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A farmer presents several chicks ranging from 10-14 days of age. Most have curled up toes and walk on their hocks, but a few have paraparesis with splayed legs.

The leg muscles are atrophied and flabby.

Which one of the following choices is the most likely diagnosis?

A - Granulomatous neuritis
B - Riboflavin deficiency
C - Marek's disease
D - Newcastle disease
E - Floppy chick disease

This is an example of riboflavin deficiency which causes decreased egg production and decreased hatching of eggs. The deficiency affects the myelin sheaths of main nerves causing a curled toe paralysis.

Marek's disease also shows symptoms of "spread-leg" paralysis, but is not seen in chicks less than 3 weeks of age.

What is the most likely etiology of the distorted pupil in the chicken eye on the right?

Other affected chickens from this flock showed depression, transient paralysis, atherosclerosis, and persistent neurologic disease.

A - Newcastle disease
B - Tuberculosis
C - Campylobacteriosis
D - Infectious laryngotracheitis
E - Marek's disease

This is an example of the ocular form of Marek's disease, caused by an alphaherpesvirus.

One of the most characteristic lesions is enlarged peripheral nerves with loss of striations.

Newcastle disease also has a neurological component, but not the distorted pupils.

A pig farmer complains of strange behavior in his feeder pigs. Most are hyperexcitable yet are not squealing. A few are lethargic, wandering aimlessly and seem to be blind.

Bloodwork shows a marked increase in sodium concentration. Upon inspection of the pen, it turns out that the waterer had been inadvertently turned off.

Which one of the following treatments is indicated?

A - Frequent small amounts of water
B - Ad lib water
C - Ad lib water and IV 1/2 strength Ringers solution
D - Furosemide
E - Mannitol

Frequent small amounts of water. It is dangerous to rapidly correct for a hyperosmolar or hypoosmolar state (salt toxicity) and could lead to brain swelling.

It is best to gradually rehydrate the animals with small amounts of water given frequently. Also, IV 1/2 strength Ringers solution with 2-1/2 % dextrose can be given at a slow rate.

A 4-year-old stallion presents with urine scald, fecal retention and a right head tilt. Rectal examination reveals atonia of the anus and rectum, however, no fracture is palpated.

Which one of the following tests is most indicated?

A - Tibial muscle and nerve biopsies
B - Cervicothoracic spinal radiography
C - Antibodies against P2-myelin protein
D - Immunoblot against DNA fragments from P tenuis
E - Search the pasture for yellow star thistle

Antibodies against P2-myelin protein. Horses with polyneuritis equi have circulating antibodies against P2-myelin protein. Other diseases to rule out in this case would be equine herpesvirus-1 and equine protozoal encephalomyelitis.

A positive immunoblot test for Sarcocystis neurona antibodies in the serum of a horse indicates which one of the following?

A - Poor response to treatment for equine protozoal myeloencephalitis
B - Favorable response to treatment for equine protozoal myeloencephalitis
C - The horse has been in Africa
D - Exposure to equine protozoal myeloencephalitis
E - Definitive diagnosis of equine protozoal myeloencephalitis

Exposure to the organism. There is NO definitive ante mortem test for equine protozoal myeloencephalitis (EPM), although immunoblot for antibodies on the cerebrospinal fluid is suggestive of the disease and a rationale to start treatment in a horse with clinical neurologic signs.

Which one of the following diseases have been linked with the variant form of Creutzfeldt-Jakob disease (vCJD) in humans?

A - Bovine spongiform encephalopathy
B - Sporadic bovine encephalomyelitis
C - Q fever
D - Equine West Nile virus encephalitis
E - Eastern equine encephalomyelitis (EEE)

Bovine spongiform encephalopathy (BSE) suddenly appeared in the mid 1980's in the UK, likely due to changes in the practice of feeding meat and bone meal of sheep origin. In 1997, it was confirmed that Creutzfeldt-Jakob disease was associated with the bovine disease.

Sporadic bovine encephalomyelitis (SBE), caused by Chlamydia pectoris (also called Chlamydophila pecorum), is not known to cause disease in humans.

The 11-year-old spayed female cat shown below is presented with generalized weakness and unable to lift her head.

The owners have noticed her at the water bowl more often and she seems to be urinating more in the last month.

Which blood chemistry test would be most likely to diagnose cause of her weakness?

A - Calcium
B - Sodium
C - Potassium
D - Bicarbonate
E - Chloride

Potassium. This is a classic presentation of a cat with hypokalemic myopathy which is often due to potassium loss from renal disease.

Other causes of generalized weakness and neck ventroflexion include polymyositis, organophosphate toxicity, myasthenia gravis.

The patellar reflex tests the integrity of which one of the following nerves?

A - Peroneal
B - Sural
C - Tibial
D - Sciatic
E - Femoral

Femoral. The patellar reflex is a monosynaptic reflex that tests the integrity of the femoral nerve and the L4-L6 spinal segments.

The sciatic nerve is tested with the withdrawal reflex.

The menace response is used to test which cranial nerves?

A - II and VII
B - I and VIII
C - IX and X
D - V and VIII
E - V and VII

The menace response is used to test visual input (cranial nerve II - optic) and blink response (cranial nerve VII - facial). Take care not to induce air movement which would elicit a tactile response (cranial nerve V - trigeminal) instead of visual.

There are many mnemonics to help memorize the cranial nerves. Click here for mnemonics courtesy of Neuromonkey.

A 5-year-old intact male Cocker Spaniel is presented with severe lower back pain. The dog is ambulatory but too fractious to examine reflexes or conscious proprioception. The dog is sedated and carefully lateral radiographs are made of the lumbar spine. The radiograph is shown below.

What is your diagnosis?

A - Renal calculi
B - Spinal fracture
C - Discospondylitis
D - Intervertebral disc disease
E - Cauda equina syndrome

Spinal fracture. The dorsal spinous processes of L4, L5, and L6 are fractured. Spinal fractures can be very unstable so care must be used to prevent further injury of the spinal cord, especially in the sedated or anesthetized animal.

A 15 year old cat is presented with a 3 week progression of wandering in circles to the left, standing in corners, and dull mentation.

Conscious proprioceptive deficits (knuckling) can be elicited in the right thoracic and right pelvic limbs.

There is a decreased menace response on the right, but pupillary light reflexes are normal in both eyes. The examination is otherwise normal. A brain tumor is suspected.

Where is the most likely location of the lesion?

A - Left cerebrum
B - Right brainstem
C - Right cerebrum
D - Left brainstem
E - Cerebellum

Left cerebrum.
Remember that conscious proprioception and visual perception are affected by lesions in the contralateral cerebral hemisphere.

Circling direction is generally toward the side of the lesion.

A 4-year-old Rat Terrier is presented with a 3 day history of progressive stumbling and falling.

Physical exam reveals a right head tilt, left sided hypermetria, generalized ataxia and vertical nystagmus.

Which one of the following choices is the most likely diagnosis?

A - Fibrocartilagenous embolism
B - Granulomatous meningoencephalitis
C - Ascending and descending myelomalacia
D - Amyotrophic lateralizing sclerosis
E - Central pontine myelinolysis

Granulomatous meningoencephalitis.
The lesion in this case localizes to the left cerebellum causing the left hypermetria and a right paradoxical head tilt.

Granulomatous meningoencephalitis often affects this area.

Another top differential would be a cerebellar neoplasm.

Acquired equine motor neuron disease is a disease characterized by weight loss, paresis with trembling, preference to lying down, and decreased activity.

Which one of the following choices is associated with this disease?

A - Thiamine deficiency
B - Lead toxicosis
C - Organophosphate toxicosis
D - Vitamin E deficiency
E - Rickettsial infection

Vitamin E deficiency. Acquired equine motor neuron disease uncommon today due to horse owner awareness. When it occurs, it is usually seen in older adult horses.

Owners may say that the horse can "walk better than it can stand" when a horse has acquired equine motor neuron disease. The horse will stand still trembling in a tucked up stance, but it will walk well (but in short strides).

A 1 year-old Thoroughbred stallion is presented with difficulty walking for the past week.

Examination reveals ataxia in the pelvic limbs and there is a tendency for him to overreach in all four limbs when ambulating.

Which one of the following choices is the most common cause of these signs in the horse?

A - Tetanus
B - Botulism
C - Cervical vertebral malformation/malarticulation
D - Lead toxicity
E - Occipitoatlantoaxial malformation/malarticulation

Cervical vertebral malformation/malarticulation is a common cause of these symptoms.

Occipitoatlantoaxial malformation is a rare congenital defect seen in Arabian breeds. Botulism and tetanus may cause stiffness and/or weakness, but not ataxia and overreaching.

Other differentials in the case above would include degenerative myeloencephalopathy and equine protozoal myelitis.

The 4-year-old neutered male German Shepherd mix shown below is presented with difficulty eating.

Physical exam reveals that he is unable to close his jaw.

Range of motion of the jaw is normal and the rest of the examination is normal.

Which one of the following choices is the most likely diagnosis?

A - Masticatory myositis
B - Rabies
C - Bell's palsy
D - Trigeminal neuritis
E - Distemper

This is the clinical picture of trigeminal neuritis. Bilateral damage to the motor component of cranial nerve V would result in the inability to CLOSE the jaw.

Masticatory myositis causes inability to OPEN the jaw.

A five-month-old Yorkshire terrier is presented with ataxia in all four limbs and neck pain.

There is loss of conscious proprioception in all four limbs. A radiograph of the cervical spine is shown below.

Which one of the following choices is the most likely diagnosis?

A - Discospondylitis
B - Caudal occipital malformation
C - Atlantoaxial instability
D - Spina bifida
E - Intervertebral disk disease

This is atlantoaxial instability. There is increased distance between the cranial aspect of the dorsal spinous process of C2 and the caudal aspect of the dorsal arch of C1 indicating instability of C1-C2.

Atlantoaxial instability is usually seen in toy dog breeds under a year or two of age.

Caudal occipital malformation involving the foramen magnum is seen most often in Cavalier King Charles Spaniels.

Which one of the following choices is the basic structural component that constitutes a urine cast?

A - Desquamated epithelial cells
B - Red blood cells
C - Mucus
D - Leukocytes
E - Tamm-Horsfall protein

Casts are made up of Tamm-Horsfall proteins. These are high molecular weight mucoprotein produced by the distal tubular epithelial cells of the kidney.

The presence of casts may indicate tubular damage but not the severity of the change. Casts may also contain cellular debris (WBC, RBC, epithelial cells) or fat.

Within urine sediment, mucus looks like homogeneous, ribbon-like material.

A 7 year-old cat is presented with miosis, ptosis, enophthalmos, and protruded nictitating membrane involving the right eye.

These symptoms are caused by damage to which one of the following innervation pathways?

A - Left oculomotor innervation to the eye
B - Right parasympathetic innervation to the eye
C - Right sympathetic innervation to the eye
D - Left vagal innervation to the eye
E - Right trigeminal innervation to the eye

Right sympathetic innervation to the eye. Horner's syndrome(miosis, ptosis, and enophthalmos) is caused by defective ipsilateral sympathetic innervation to the affected eye.

Loss of parasympathetic innervation (via the oculomotor nerve) to the eye would cause a dilated pupil.

Trigeminal damage would result in decreased sensation to the eye.

A 2 year-old Bernese Mountain Dog is presented for acute pelvic limb paralysis while outside chasing a cat.

In the exam room, the dog is dragging the right pelvic limb and barely walking on the left pelvic limb.

Exam reveals decreased conscious proprioception in the left pelvic limb and absent conscious proprioception in the right pelvic limb. Patellar reflexes are absent on the right and intact on the left.

No back pain can be elicited. The rest of the neurologic exam is normal. You strongly suspect a fibrocartilaginous embolism.

Which of the following tests can show concrete evidence of a fibrocartilaginous embolism?

A - Magnetic resonance imaging
B - Acetylcholine receptor antibody test
C - Myelography
D - Computerized tomography
E - Cerebrospinal fluid analysis

Magnetic resonance imaging. Fibrocartilaginous embolism can be confirmed only via magnetic resonance imaging.

Myelography, cerebrospinal fluid analysis and computerized tomography are usually normal. Acetylcholine receptor antibody test is used to diagnose acquired myasthenia gravis.

The 12-year-old spayed female cat shown below is presented with a history of weakness for the past 2 days. She has neck ventroflexion and a stiff, stilted gait.

Which one of the following is in the top of the differential list?

A - Bilateral otitis media/interna
B - Caudal occipital malformation
C - Hyperkalemic periodic paralysis
D - Cervical vertebral malformation
E - Hypokalemic myopathy

Hypokalemic myopathy.
The posture is classic for hypokalemia and other neuromyopathies (e.g., myasthenia gravis, organophosphate intoxication) in cats.

Hyperkalemic periodic paralysis has not been reported in cats.

Which of the following pairs of tissues can both cause increased serum alanine aminotransferase (ALT) levels in dogs and cats?

A - Heart and kidneys
B - Liver and muscle
C - Spleen and liver
D - Kidneys and pancreas
E - Pancreas and intestine

Damage to liver and muscle cells of dogs and cats causes increased serum levels of alanine aminotransferase (ALT).

ALT is a considered a "leakage" enzyme. High levels are normally found in the cytoplasm of healthy cells. When hepatic or muscle cells are damaged, ALT leaks into adjacent tissue where it is picked up by the venous circulation.

Other species such as horses, ruminants, pigs, and birds do not have high levels of ALT inside cells. Aspartate aminotransferase (AST) is the leakage enzyme predominant in these species.

The magnitude of the elevation of leakage enzymes can be deceiving - are a few cells leaking a lot or many cells are leaking a small amount? Severe damage to a healthy liver may result in very high levels, while low levels may be seen when significant atrophy or fibrosis of the liver is present and few cells are left. Prognosis of the former may be good, for the latter it is certainly grim.

Differentiation between muscle and liver as the source of increases in ALT/AST is determined by evaluation of other muscle (creatine phosphokinase (CK) and AST) and liver enzymes (AST, sorbitol dehydrogenase (SDH), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP)), the species, and the clinical evaluation.

Leakage enzymes do NOT provide an estimate of actual liver function. This is evaluated by measurement of substances dependent on the efficacy of liver function such as bile acids, blood urea nitrogen, albumin, and glucose.

In which one of the following cattle breeds is syndactyly most commonly inherited?

A - Holstein-Friesian
B - Angus
C - Hereford
D - Simmental
E - Brown Swiss

Holstein-Friesian cattle inherit syndactyly, or "mule foot", a simple autosomal recessive trait, more often than other breeds. Syndactyly is the partial or complete fusion of the digits of one or more feet. Forefeet are affected most often.

Affected animals walk slowly, usually with a high-stepping gait. They may also be more prone to hyperthermia than normal cows.

Swainsonine is a toxic compound present in which one of the following plants?

A - Persea americana (Avocado)
B - Pteridium aquilinum (Bracken fern)
C - Astragalus flavus (Milk vetch)
D - Prunus virginiana (Chokecherry)
E - Nerium oleander (Oleander)

Swainsonine is found in many species of Astragalus and Oxytropis, called locoweeds, vetches, or milk vetches.

Ingestion of swainsonine causes neurologic signs of cerebral disease, called "locoism" in livestock. Behavior changes, aggression, ataxia, depression, circling, and vision loss are some of the clinical signs seen.

Recovery is possible with removal of the source, but since locoweed is palatable, animals may eat it again even when other forage is available.

Cattle consuming locoweed at high altitudes can develop congestive heart failure, called "High mountain disease". Pulmonary hypertension causes excessive strain on the heart muscle.

Nerium oleander (Oleander) contains cardiac gylcosides.
Pteridium aquilinum (Bracken fern) contains glycosides and thiaminase.
Persea americana (Avocado) contains persin.
Prunus virginiana (Chokecherry) contains cyanide

A 10 year old Quarterhorse gelding pastured in the northeastern United States is presented for weakness and depression. The owner reports that the horse's urine is an unusually dark brown color.

On physical exam, the horse is tachycardic and tachypneic. The mucous membranes are a dark yellowish brown.

The horse's plasma has a pink tinge. A CBC, blood smear, biochemistry panel, and urinalysis indentify intravascular hemolytic anemia, hemoglobinemia, methemoglobinemia, and hemoglobinuria.

Erythrocytes are seen on the blood smear with Heinz bodies and eccentrocytosis.

Ingestion of which one of the following plants is most likely to cause of this spectrum of clinical signs in this case?

A - Quercus spp (Oak)
B - Xanthium spp (Cocklebur)
C - Tetradymia spp (Horsebrush)
D - Veratrum spp (Skunk cabbage)
E - Acer rubrum (Red maple)

Ingestion of Acer rubrum (Red maple) is most likely the cause of hemolytic anemia and the resultant pathology in this horse.

Wilted or dry leaves and bark of red maple trees contain oxidants which damage red blood cell (RBC) membranes, resulting in the formation of Heinz bodies and eccentrocytes. Acute intravascular hemolysis, hemoglobinemia, methemoglobinemia, hemoglobinuria, and methemoglobnuria follow.

Clinical signs of toxicity include: weakness, depression, tachypnea, tachycardia, icterus, cyanosis, and brown discoloration of blood and urine.

Post mortem findings include: icterus, splenic hemosiderosis, splenomegaly, swollen dark red-blue black kidneys with red-brown tubular casts, and a swollen brown liver.

Toxicity is often fatal. If the horse survives the hemolytic crisis, renal failure may develop due to pigmenturia.

Treatment is supportive care: IV fluids, oxygen, and blood transfusions.

Which one of the following management recommendations is most helpful to reduce the incidence of mare reproductive loss syndrome?

A - Remove the horses from affected pastures
B - Vaccinate mares and stallions against equine coital exanthema
C - Progesterone supplementation between 4-6 months of pregnancy
D - Spray paddocks to kill Habronema muscae larvae
E - Cut down all the black walnut trees on premises

Removal of mares from affected pastures is necessary for control of mare reproductive loss syndrome (MRLS). The exact pathogenesis of MRLS is still unknown, however, it is associated with exposure to/ingestion of "hirsute" or hairy catepillars.

The eastern tent caterpillar was associated with the first outbreak in Kentucky in 2001-2 where over 3000 pregnant mares aborted. Other episodes have been seen in Florida (2005) and Australia (2007) with exposure to other species of hirsute catepillars.

The most current theory - damage to the oral mucosa or intestinal lining by the setae (spines) of the catepillars introduces bacteria that causes bacteremia and subsequent infection of the fetus and/or placenta.

Early embryonic loss, abortion, stillbirths, weak foals, and infected foals are seen. Swollen umbilical cords are also often seen in aborted fetuses.

Feeding hay and removal of wild cherry trees, a major food source for the caterpillars, is also beneficial in reducing the incidence of MRLS abortion.

A 4 month old calf from a small beef herd presents with a fracture of the right metatarsus. He was normal last night.

The owner found the calf this morning after rounding up the herd for deworming.

This is the 5th calf this season with fractured bones. One had a vertebral fracture, two calves had humeral fractures, and one other had a cannon bone fracture.

Which one of the following choices is the most likely problem in this herd?

A - Low dietary protein
B - Low dietary copper
C - High dietary calcium
D - Hypovitaminosis D
E - High dietary phosphorus

Low dietary copper levels (Cu) causes bones of growing animals to be brittle because they do not develop the normal trabecular structure. Higher fracture rates are seen in Cu deficient than in Cu replete animals.

Pathologic fractures are more common during periods of exertion, such as the morning round up.Rough handling exacerbates the number of fractures.

Treatment of Cu deficiency includes copper glycinate injections, and feeding of mineral mixes with Cu. Copper boluses can also be given.

In areas with high levels of molybdenum (Mb) in the soil, Cu levels are often low. Mb interferes with absorption of Cu, hence Mb excess results in Cu deficiency.

Pathologic fractures can be seen with hypovitaminosis D growing cattle, but this is unlikely in animals on pasture.

Calcium deficient calves may also develop a similar syndrome of pathologic fractures.

Which one of the following conditions occurs in the Fall in temperate climates, among cattle moved from poor pasture to lush pasture?

A - Hypocalcemic paresis
B - Vagal indigestion
C - Acute bovine pulmonary emphysema and edema
D - Verminous bronchitis (Husk)
E - Rumenal hyperkeratosis

Acute bovine pulmonary emphysema and edema(ABPEE) is associated with Fall onset, occurring 5-10 days after changing cattle from poorer to better, often lush, pasture.

Toxicity occurs because rumen micro-organisms convert L-tryptophan in lush pasture grasses to pneumotoxic 3-methylindole, which damages respiratory epithelial cells.

Acute bovine pulmonary emphysema and edema(ABPEE) is associated with Fall onset, occurring 5-10 days after changing cattle from poorer to better, often lush, pasture.

Toxicity occurs because rumen micro-organisms convert L-tryptophan in lush pasture grasses to pneumotoxic 3-methylindole, which damages respiratory epithelial cells.

Remove fermented rumen contents, flush with saline.

This is the clinical picture of a ruminal drinker calf with chronic indigestion from milk deposited directly into the rumen.

Treat by removing the fermented material and flushing the rumen with saline. Attempt to induce gastric/reticular groove closure during feeding by inducing vigorous sucking activity with a finger before feeding milk. If calves relapse, consider weaning.

The problem occurs due to failure of the gastric groove reflex, which normally shunts milk directly into the abomasum, (bypassing the rumen). Most often seen in bucket fed calves who gulp their milk.

Several rabbits in a commercial meat operation have developed genital scabs, perineal ulcerations a crusty exudate around the nose and eyes. Microhemaglutination tests are positive for treponematosis.

Which one of the following steps is most effective to treat this problem?

A - Amprolium-medicated feed for whole herd, 2 weeks; Increase ventilation
B - Clindamycin PO for exposed rabbits, 8 days; Cull affected animals
C - Amipcillin PO for affected rabbits, 10-14 days
D - Isolate affected animals, Lincomycin in water 2-3 weeks
E - Penicillin IM for all rabbits, 5-7 days

Treat ALL rabbits with parenteral (IM) penicillin when there is an outbreak of Treponema cuniculi (tremponematosis). Tetracycline or chloramphenicol are also effective

AVOID oral antibiotics in rabbits, which can upset normal gram-positive gut flora.

Particularly avoid lincosamide antibiotics like Clindamycin and Lincomycin, which target gram-postive bacteria and are specifically contraindicated in rabbits and rodents

What nerve(s) need to be blocked in order to dehorn cattle?

A - Auriculopalpebral and Infraorbital
B - Cornual
C - Cornual and Infratrochlear
D - Auriculopalpebral
E - Infratrochlear

Typically a cornual nerve block (branch of the trigeminal- midway between eye and base of horn, just below temporal line) will anesthetize most cows for dehorning. If that is not enough, do a ring block around the base of the horn.

In contrast, for goats you need to block BOTH the cornual nerve (caudal ridge, root of zygomatic arch of frontal bone) and infratrochlear nerve (dorsomedial to eye, close to edge of bony orbit) before dehorning. This is because the goat horns lie more rostral on the skull and closer to the bony orbits than the horns of a cow.

A SLAP® heartworm antigen test with a reported sensitivity 96% and specificity of 98% is being used.

Assuming the prevalence of heartworm in the area is 10%, what is the predictive value positive (PVP) of the test?

A - 80%
B - 88%
C - 99%
D - 84%
E - 92%

PVP is 84%. The trick with this kind of question is to pick an imaginary number of animals that you test, like 1000, and fill out your 2x2 table from there. Follow the links to see diagrams step by step.

If prev is 10% then there must be 100/1000 dogs with heartworm and 900 dogs that are disease-free.

A 96% sensitive test will correctly call 96/100 positive (box "a"), and IN-correctly call 4/100 negative, (box "c": these are the false negs).

If 100/1000 animals are infected, then 900/1000 are disease-free. Your 98% specific test will correctly call 882/900 disease-free (box "d": 0.98 X 900=882) and IN-correctly call 18/900 positive, (box "b": these are the false pos).

Now your a,b,c,d boxes are all filled, it is easy to calculate PVP=a/(a+b)=96/(96+18)=84%

What percentage of dairy cows have a retained placenta after calving?

A - 30-40%
B - 20-30%
C - 5-15%
D - 25%
E - 1-4%

Retained placenta occurs in 5-15% of dairy cattle. Very common, about 1 in 10 calvings. NORMALLY, the placenta is expelled in 3-8 hours. If it's still there 12-24 hours after calving, it's retained.

Typically, retained placentas are dispelled spontaneously after 4-10 days as the caruncles necrose.

An owner may insist you pull it out. Manual removal is usually not helpful-should only be done if placenta comes out with GENTLE traction. Manual removal is contraindicated if cow has signs of septicemia- removal may cause a septic metritis, peritonitis.

Which one of the following conditions predispose a cow to metritis?

A - Milk fever, Malnutrition, Excess dietary zinc
B - Dystocia, Overfeeding in dry period, Ca-P imbalance in feed
C - Contaminated calving environment, Abortion, Hypomagnesemia
D - Strep. agalactiae mastitis, Retained placenta, Laminitis
E - Agalactia, Milk fever, Bovine vibriosis

Cows are predisposed to post-parturient Bovine metritis by many things: Dystocia, Overfeeding in dry period, Ca-P imbalance in feed. Also predisposed by Retained placenta, Contaminated calving environment, Abortion, Malnutrition. Infectious causes of metritis include Brucellosis, Leptospirosis, Trichomoniasis, Bovine campylobacter.

Which organism determines the minimum temperature needed to pasteurize milk in the United States?

A - Listeria monocytogenes
B - Brucella abortus
C - Mycobacterium bovis
D - Escherichia coli
E - Coxiella burnetii

Temperature of pasteurization is set by the toughest, most heat-resistant organism, which is Coxiella burnetii, the cause of Q fever. If the temperature is high enough, for long enough to kill Coxiella, it will also kill the other organisms.

Historically, bovine TB, (Mycobacterium bovis) was the organism that prompted pasteurization ordinances.

Brucella and Listeria can also be transmitted in milk.

E. coli is typically a contaminant from unsanitary milking conditions.

Milk pasteurization standards in the United States are detailed in the Grade A Pasteurized Milk Ordinance. Basically, the higher the temp, the shorter the pasteurization time needed. ie: 90 C (194 F) for 0.5 seconds, or 100 C (212 F) for 0.01 seconds. (see item 16p)

Which one of the following neonatal calf diarrheas has public health/zoonotic significance?

A - Colibacillosis, Ostertagiasis
B - Colibacillosis, Rotavirus
C - Cryptosporidiosis, Salmonella
D - Salmonella, Coccidiosis
E - Clostridium perfringens, Coronavirus

Cryptosporidiosis is caused by a protozoa implicated in drinking water-associated outbreaks of diarrhea in humans; Salmonellae can infect humans from a number of different sources (turtles, chickens, eggs)

E. Coli can cause human disease, but Ostertagia and bovine rotavirus do not. (There IS a human version of rotavirus, however)

C. perfringens can be found in soil and in the normal gut flora and is not contagious.

A 3-month old calf is presented for necropsy. The calf collapsed and suddenly died this morning after she escaped and was chased around the back pasture for 45 minutes by her owner.

Among other things, endocardial plaques in the left ventricle of this calf's heart are discovered.

What advice should be given the farmer?

A - Treat the other calves with vitamin E/Selenium
B - Check the mother for bovine leukosis by AGID
C - Take all the calves off ionophore-containing feed
D - Start the other calves on Ceftiofur (Naxcel ®)
E - Search the calf barn for sources of lead

Treat the other calves with vitamin E/Selenium. Think White Muscle Disease when you see SUDDEN DEATH and endocardial PLAQUES in a young calf, lamb or kid with a history of recent VIGOROUS EXERCISE. Follow this link to a Merck image of pale ventricular myocardium.

Typically seen in young, fast-growing animals (ie: calves 2 weeks-6 mos) Clinical signs may include dyspnea (due to myocardial disease), stiff gait, arched back, weakness, recumbent but BAR (bright, alert, responsive).

Sudden death may resemble enterotoxemia, should see acute bloody diarrhea, convulsions, opisthotonos in first days of life with enterotoxemia.

A cow is presented on emergency with urea/non-protein nitrogen toxicity.

What is the treatment of choice?

A - Atropine, Protopam chloride IV q 4-6 hours
B - Rumenal infusion 2-8 liters vinegar,3-10 gallons cold water
C - Rumenotomy
D - IV Fluids with MgSO4, Na thiosulfate PO
E - Relieve bloat, drench with 2-8 liters sodium bicarbonate

Treat Urea/non-protein nitrogen (NPN) toxicity with a rumenal infusion 2-8 liters 5% acetic acid (vinegar) and 3-10 gallons of cold water. The vinegar decreases rumenal pH which slows absorption of un-ionized ammonia. Repeat Q 6 hours up to 48 hours. Best results if animal is still ambulatory.

It is often impossible to treat these cases before they die because of rapid progression to death. If possible, Rx with IV fluids. If necessary, relieve bloat.

Urea/NPN toxicity is related to ammoniated feed toxicity which causes so-called "Bovine bonkers". Manage ammoniated feed toxicity by removing the ammoniated feed and treating severe cases with anticonvulsants like diazepam, pentobarbital.

Abortions due to brucellosis tend to occur at what stage of pregnancy?

A - Third trimester
B - At any time during pregnancy
C - Second trimester
D - Last half of pregnancy
E - First trimester

Typically, Brucellosis causes abortion in the LAST HALF of pregnancy, for the 5th month onwards. Last trimester is also a good answer, though not entirely correct. You might remember "Bruce is always late".

Expect STILLBORN calves. Cows only abort ONCE.

Brucellosis is REPORTABLE.

The vaccines used are the Brucella abortus strain 19 vaccine or the RB51 vaccine, given to heifer calves 4-12 months old, along with a USDA tattoo in the right ear. Remember: "The right ear is the RIGHT EAR".

BVD and Trichomoniasis (occasionally) can cause early abortion in cows, but MOST things cause abortion late, like 3rd trimester.

Listeriosis and Arcanobacterium pyogenes can cause abortion at any time during pregnancy.

Among mixed-sex twins in cows (ie: a male twin and a female twin), what % of female twins are sterile freemartins?

A - More than 90%
B - Less than 10%
C - 30-50%
D - 60-80%
E - 10-30%

Freemartins are sterile female calves, born twin to a male in up to roughly 92% of mixed twin calvings.

In twin pregnancy, the male fetus differentiates first, and transfers XY antigens across chorionic placental blood vessels, which inhibits development of the ovaries in the female twin.

THINK SMALL: May have small vulva, small stature. Look for a short vagina, no cervix, anestrus, On rectal feel HYPOPLASIA of uterus (small). Can sometimes detect 2 bloodtypes in single animal


A middle-aged dog was recently diagnosed with hyperadrenocortism. The owner has questions regarding skin lesions on this animal.

There are erythematous papules and raised firm lesions. A single skin scraping is negative for mites, but there is gritty material in the scraping.

Which one of the following choices is the most likely diagnosis?

A - Flea allergy dermatitis
B - Superficial pyoderma
C - Calcinosis cutis
D - Squamous cell carcinoma
E - Demodecosis

Calcinosis cutis. This commonly occurs in dogs with Hyperadrenocorticism. Often the skin calcification is visible on radiographs.

Secondary demodecosis can occur in dogs with hyperadrenocorticism, but the lesions are characterized by focal alopecia, erythema and comedones. A skin scraping or skin biopsy can differentiate the two conditions.

An obese 7-year-old Labrador Retriever presents for annual vaccinations.

The owners claim that they have restricted his diet and try to exercise him but he still keeps the weight on. There is alopecia on the dorsum of his tail and he has an unusual worried facial expression.

Which one of the following choices is the most likely diagnosis?

A - Hypoadrenocorticism
B - Hyperadrenocorticism
C - Sarcoptic mange
D - Hypothyroidism
E - Male pattern alopecia

Tail alopecia and tragic facial expression are a classic signs of Hypothyroidism in dogs.

Other areas of bilateral alopecia that are common in hypothyroidism are the ventral and lateral trunk, caudal thighs, ventral neck and dorsum of the nose.

Hyperadrenocorticism commonly has truncal alopecia and also presents with obesity. It is more common in toy dog breeds.

Oxalate is the toxic agent found in which one of the following plants?

A - Hordeum spp (Foxtail)
B - Solanum spp (Nightshade)
C - Delphinium spp (Larkspur)
D - Hypericum perforatum (Klamathweed)
E - Sarcobatus vermiculatus (Greasewood)

Oxalates are found in Sarcobatus vermiculatus (Greasewood). Greasewood toxicity is seen primarily in sheep, sometimes in cattle, usually when large amounts are consumed over a short period of time.

Oxalates occur in plants as salts of calcium, sodium, and potassium. Calcium oxalate is insoluble and is lost through the GI tract.

Sodium and potassium oxalates are soluble and either 1) bind to calcium in the rumen and lost through the GI tract, or 2) are absorbed and react with calcium in body fluids. Death is attributed to hypocalcemia and/or kidney failure caused by calcium oxalate crystals in the renal tubules.

Signs of oxalate toxicity include: dullness, lowering of the head, loss of appetite, separation from the herd; followed by excessive salivation with frothing, progressive incoordination; and finally, coma, irregular breathing, and death.

Oxalate containing plants include: Sarcobatus (greasewood), Oxalis (sorrel), Rumex (dock), Halogeton, Amaranthus (pigweed), and Chenopodium (lambsquarter.) Oxalates are also produced by molds (Aspergillus niger) in contaminated feeds.

Delphinium spp (Larkspur) contain alkaloids.
Hypericum perforatum (Klamathweed) contain hypericin.
Hordeum spp (Foxtail) cause physical injury.
Solanum spp (Nightshade) contain alkaloids.

Benzodiazepines act in upon which one of the following receptors?

A - Dopamine
B - Gamma amino butyric acid
C - N-methyl-D-aspartate (NMDA)
D - Alpha - adrenergic
E - Muscarinic type cholinergic

The gamma amino butyric acid receptor (GABA) is the site of action of benzodiazepine (BZ) tranquilizers, and many other drugs.

Barbiturates, inhalant anesthetics, and propofol all have binding sites on the GABA receptor. GABA is the primary inhibitory neurotransmitter in the brain of mammals.

Binding of a BZ enhances the binding of GABA to its receptor. This results in hyperpolarization of the cell and inhibition of neuronal activity. Sedation, muscle relaxation, and anti-seizure effects are seen with BZs.

Diazepam and midazolam are the BZs used most often in veterinary medicine. Zolazepam is found in combination with tiletamine in the general anesthetic Telazol®.

BZs are commonly used in combination with opioids as premedication prior to general anesthesia in older or compromised patients. Agitation can be seen when given as premedication to young healthy patients, especially cats.

Ketamine acts upon N-methyl-D-aspartate (NMDA) receptors in the spinal cord. The potent sedatives xylazine, medetomidine, romifidine, and detomidine, etc. act primarily at alpha-2 receptors.

Cholinergic receptors are normally activated by acetylcholine and are blocked by atropine and glycopyrrolate. Dopamine acts at dopamine receptors.

Which one of the following choices is a side effect of xylazine in horses?

A - Sweating
B - Hypoxemia
C - Excitement
D - Tachycardia
E - Diarrhea

Sweating is seen in horses sedated with xylazine and all alpha-2 agonists. The specific mechanism is not known, but interference with thermoregulation in the hypothalamus is thought to be involved.

Although respiratory rate and volume are both decreased, hypoxemia does not develop in normal horses.

Alpha-2 agonists cause a reflex bradycardia - the heart rate decreases in response to the high blood pressure caused by vasoconstriction caused by alpha-2 receptor stimulation. This is a baroreceptor-type response of the cardiovascular system to maintain blood pressure within the normal range.

Alpha-2 agonists cause ileus that can be significant with high doses and in combination with other anesthetic agents, but does not cause diarrhea.

Analgesia, muscle relaxation, ataxia, and dose dependent sedation are also seen, not excitement.

Which one of the following choices is the most common etiology of canine cholangiohepatitis?

A - Toxicity
B - Neoplastic biliary obstruction
C - Liver fluke migration
D - Ascending infection
E - Idiopathic

Enteric bacteria migrate up the bile duct from the intestines and create an infection in the liver and biliary tract in most cases of canine cholangiohepatitis.

Feline cholangiohepatitis is more common than the canine form and has three main etiologies.
1. Acute neutrophilic (suppurative)
2. Chronic (lymphoplasmacytic or mixed)
3. Lymphocytic (nonsuppurative)

A female veterinarian is pregnant and her physician tests her serologically for toxoplasmosis.

IgM is negative.
IgG is positive

What is the most appropriate interpretation?

A - Both mother and baby are safe
B - Need to re-check in 2 weeks for rising titers
C - Mother at risk, baby is safe
D - Mother is safe, baby at risk
E - Both mother and baby at risk

Both mother and baby are safe. The toxoplasmosis organism causes birth defects in a developing fetus if a mother is infected for the first time in her life while pregnant (ie: IgM positive while pregnant).

Toxoplasmosis is not generally dangerous to immune-competent people and a positive IgG result suggests an old infection.

There are challenges to toxoplasmosis testing in pregnant women (false positives). If a pregnant woman is IgM positive, confirmatory tests must be done.

A dozen young chickens at a broiler-raising facility are found dead on their backs and sides with no premonitory signs.

Necropsy of a dead bird shows good body condition and no particular pathology. What is the most likely clinical diagnosis?

A - Dissecting aneurysm
B - Newcastle disease
C - Highly pathogenic avian influenza
D - Ascites syndrome
E - Flip over disease

This is the clinical picture of flip-over disease, a production-related disease associated with intensive husbandry. The cause is not known but thought to be related to high carbohydrate intake. Ventricular fibrillation may be the cause of sudden death, and a lack of gross pathology is common.

Because broilers affected with flip over disease frequently die on their backs, differential diagnosis includes ascites syndrome (waterbelly). Sick birds with ascites syndrome typically show clinical signs like cyanosis, panting and abdomens distended by fluid. Essentially a form of right ventricular heart failure secondary to pulmonary hypertension or more rarely, hepatic failure.

Dissecting aneurysm is another cause of sudden death, but animals display severe hemorrhage on necropsy. Click here to see a necropsied chicken with frank abdominal hemorrhage and a ruptured aorta

Which group is most at risk of developing the lesion evident in this image?

(Myxomytous mitral valve disease)

A - Older, small-breed dogs; Cavalier King Charles Spaniel
B - Sheep or goats pastured above 2000 meters; Saanens
C - Cattle without reticular magnets; Charolais
D - Obese cats, any breed; Burmese cats
E - Young horses ingesting Perilla mint; Standardbreds

This is endocardiosis (degenerative valve disease). Note the nodular thickening of mitral valve margins. Degenerative valve disease is the most common cardiac disease of dogs, accounting for about 75% of all canine cardiovascular disease.

Roughly 60% of affected dogs have myxomatous degeneration of the mitral valve. Older, small-breed dogs have a higher incidence and Cavalier King Charles Spaniels are prone.

Don't confuse endocardiosis, a degenerative disease with infective endocarditis which is due to bacterial infection of the cardiac valves and endocardial muscle.

An older adult cat is presented with a chronic history of coughing, wheezing, tachypnea and intermittent respiratory distress, suggesting a diagnosis of feline asthma. What thoracic radiographic pattern is most likely to be prominent?

A - Alveolar
B - Bronchiolar
C - Mixed alveolar-vascular
D - Vascular
E - Interstitial

Feline asthma classically demonstrates a bronchiolar lung pattern on thoracic radiographs (or broncho-interstitial). The hallmark of a bronchiolar pattern is irregularly thickened walls of bronchioles that look like "donuts" end-on or "tram tracks" side-on.

For an excellent visual summary of bronchiolar pattern, see Dr. Allison Zwingenberger's Vet Radiology site.

The other 3 basic lung patterns are:

1. Alveolar pattern, characterized by "air bronchograms". Click here to see examples from Drs. O'Sullivan and O'Grady's excellent summary on Thoracic radiograph interpretation.

2. Interstitial pattern, characterized by decreased visualization of pulmonary vessels, cardiac and diaphragm silhouettes. Click here to see Dr. Anne Bahr's clear discussion of radiographic lung patterns with a clinical example containing both interstitial and alveolar pattern.

3. Vascular pattern can suggest either hypervascularity or hypovascularity.
Click here to see a vascular lung pattern in the caudodorasal lung fields of a dog with severe heartworm.

A client calls in the middle of winter to say her furnace went out the night before and the whole house became very cold.

This morning one pet hamster appears to be dead and several others are lethargic.

What message should be communicated to the the owner?

A - Older animals are more likely to die from cold stress
B - Put tetracycline in the water and maintain the ambient temperature
C - Need to examine the lethargic animals and increase calorie intake
D - The other animals are likely to die
E - The hamster is not dead

The hamster is not dead. At temperatures under 41°F (5°C), hamsters will enter pseudohibernation. Though not a true hibernation, they are called "permissive hibernators".

They may look "dead" to the owner, but they are alive. Cold temperatures may also stimulate hamsters to gather up food.

This heifer has walked with an increasingly stiff and extended hock and stifle since 2 months of age. The gastrocnemius muscle is contracted, and the animal walks with short pendulum-like steps.

What advice should be given to the owner?

A - Cull
B - Vitamin E supplements
C - Radial neurectomy
D - Deep bedding, pectineus tenotomy
E - Quadriceps tenotomy

This is the typical presentation of spastic paresis, also known as Elso heel. Because spastic paresis is heritable, it is generally best to cull breeding animals.

Look for an animal with a stiff hind leg in full extension, whether walking or standing. Affected animals (especially breeding bulls) should be eliminated. Palliative surgical treatments (gastrocnemius tenotomy, tibial neurectomy) are sometimes done to give relief and salvage the animal long enough to gain weight for slaughter.

What is the function of the proventriculus in the chicken?

A - Replaces function of teeth
B - Vocalization in males
C - Glandular stomach
D - Avian version of gall bladder
E - Gizzard

The proventriculus is the glandular stomach in birds. The ventriculus (also called the gizzard), is the muscular stomach that contains grit and small rocks, and helps birds grind up hard seeds and other foods, in effect, acting like teeth.

The crop is a diverticulum of the esophagus, used for temporary food storage that empties into the proventriculus. The purpose of the crop is to allow a bird to quickly swallow what food it can, then fly to safety and digest the meal at leisure.

In hand-fed pediatric birds (usually valuable parrots), there are many potential problems possible with crop burn, crop puncture or proventricular impaction.

An immunochromatographic test kit for detection of fecal canine parvoviruses (CPV) antigen is being tested in a local cat shelter where as many as 10% of the cats there may have panleukopenia secondary to infection with the canine parvovirus.

Here are simulated test results, compared to a gold standard test for CPV.

.....................CPV pos.......CPV neg............. Total

Test kit positive..........128..............734...........862

Test kit negative..........63............1575...........1638


What is the sensitivity of this test kit?

A - 128/734
B - 734/862
C - 1575/2309
D - 1575/1638
E - 128/191

Sensitivity=128/191 (67%) a/(a+c)
This is a classic example of a 2x2 table in epidemiology, used to compare a new test (the immunochromatographic test kit) to a gold standard test (the CPV test). Draw a 2x2 table, and label the boxes a,b,c,d. Sensitivity = a/(a+c). Click here to see a Basic 2X2 table.

Feline panleukopenia virus(FPV) is closely related to type 2 canine parvoviruses(CPV-2, CPV-2a, CPV-2b). CPV-2a and CPV-2b have been shown to cause a panleukopenia-like illness in domestic cats. Click here for a PDF summary on Canine and Feline Parvovirus in Animal Shelters (may take a half minute to load) by Dr. Cynda Crawford, Maddie's Shelter Medicine Program, Univ. Florida College Vet Med.

Carprofen (Rimadyl ®) is a nonsteroidal anti-inflammatory (NSAID) commonly-used in dogs with arthritis. What is the most important side effect about which to be concerned?

A - Secretory diarrhea
B - Hypersensitivity
C - Seizures
D - Hepatopathy
E - Protein-losing nephropathy

There is a reported incidence of hepatopathy in 0.05% of dogs treated with carprofen (Rimadyl ®). Geriatric dogs, or dogs with pre-existing chronic diseases like inflammatory bowel disease (IBD), renal or hepatic insufficiency may be at a greater risk of toxic side effects. Carprofen is contraindicated in animals with bleeding disorders, like Von Willebrand's disease.

GI effects like gastric upset and gastric ulcers are LESS common with carprofen than with other NSAIDS, but still can occur.

What is the average length of estrus in the cat?

A - 4-5 days
B - 9-10 days
C - 6-7 days
D - 2-3 days
E - 21 days

Estrus in the cat generally lasts 6-7 days (range 1-10 days).

Cats are seasonally polyestrous and induced ovulators. The length of feline estrus is affected by whether a male is present. If a male is present, estrus typically lasts 1-4 days. Without a male, estrus lasts 7-10 days and recurs in 2-3 weeks.

UNlike dogs, the feline estrus cycle is controlled by day length. In North America, cats go through an anestrus period in December and January when day length is less than 12 hours.

A 3-day old female alpaca (cria) is presented in respiratory distress. The cria's cheeks flare noticeably during inspiration, and the distress is more pronounced during nursing, when the animal gasps and inhales milk.

What is the most likely diagnosis?

A - Choanal atresia
B - Mitral stenosis
C - Lung lob torsion
D - Diaphragmatic hernia
E - Wry face

Choanal atresia is one of the most common congenital problems of South American camelids. Choanal atresia occurs when the caudal nares (choanae) fail to open during embryologic development. Can be unilateral or bilateral and may cause complete or partial blockage.

What is the best way to evaluate the body condition of an adult llama?

A - Digital exam of the supraorbital fossa
B - Feel the intercostal spaces
C - Rectal exam to evaluate pelvic fat
D - Weight X height at withers X 0.28
E - Palpate over the lumbar vertebrae

Assess body condition of llamas and alpacas by palpating the amount of tissue over the lumbar vertebrae. South American camelids are adapted to high mountain environments and diets. Most adult males (and females through midgestation), maintain appropriate body condition on 10-14% crude protein grass hay with total digestible nutrients (TDN) of 50-60%. Late gestation and heavily lactating females need a higher percentage of crude protein and TDN of 65-70%. Excess legumes in the diet are not typically necessary and may cause obesity.

Zearalenone intoxication is primarily associated with which clinical signs?

A - Leukoencephalomalacia, hypertension
B - Estrogenism, vulvovaginitis
C - Immunosuppression, Hemorrhagic diathesis
D - Terminal necrosis of extremities, gangrene
E - Salivation, vomiting

Think of reproductive dysfunction (estrogenism, vulvovaginitis) with zearalenone, the only known mycotoxin with primarily estrogenic effects. Zearalenone is produced by Fusarium spp molds on plants and common feed grains like corn, barley and wheat. Often a second mycotoxin called deoxynivalenol is also prduced which causes decreased feed intake. The presence of deoxynivalenol may limit exposure to zearalenone if the animal eats less.

Fumonisin is another Fusarium spp mycotoxin associated with moldy corn. In equids, look for CNS disease (Equine leukoencephalomalacia). In pigs, see hypertension and pulmonary edema (porcine pulmonary edema-PPE).

Ergotism is caused by ingestion of alkaloids in a parasitic fungus, Claviceps purpurea, that infects small grains (rye, wheat) and forage plants like bromes, bluegrass and ryegrass. Look for vasoconstriction with terminal necrosis of the extremities due to thrombosis-affected animals are predisposed to frostbite and gangrene. May have CNS effects, potent oxytocic action or pituitary effects (decreased prolactin leading to agalactia).

Slaframine toxicosis causes profuse salivation, primarily in horses and occasionally in cattle. Due to the fungus Rhizoctonia leguminocola (black patch disease) on red clover (Trifolium pratense) especially in wet, cool years.

Trichothecenes are a group of related cytotoxic mycotoxins associated with many fungi. Think of vomitoxin (and vomiting) and also of immunosuppression. Refusal to eat contaminated feed is a typical sign, due to taste aversion. Macrocyclic trichothecene-related diseases have several specific names, including the best known, stachybotryotoxicosis.

A 12 year old neutered female black Scottish terrier is presented with a 3 week history of limping on the right fore. The lateral digit is swollen and the nail is deviated ventrally, with ulceration of the nail bed.

A lytic bone lesion of the 3rd phalanx is visible on radiograph and cytology of the mass suggests neoplasia. Chest radiographs are clear. Following amputation of the digit, histopathology indicates that the mass is a subungual melanoma.

What message should be communicated to the owner?

A - Radiotherapy is indicated
B - Best outcome with radiotherapy and chemotherapy
C - Chemotherapy is indicated
D - 95% chance she will survive 1 year
E - 50% survive 1 year, 30% local recurrence

The prognosis is poor. Melanoma of the digit is an aggressive, infiltrative tumor, with substantial metastatic potential and poorer prognosis. Median survival with resection is 12 months, with a 30% local recurrence rate. Melanomas are not thought to be responsive to radiotherapy, and the efficacy of chemotherapy for subungual melanomas is unclear.

In contrast, the prognosis is good for dogs with digital squamous cell carcinoma (SCC). 95% of dogs with digital SCC survive 1 year after amputation and 75% survive 2 years after amputation. SCC have a low metastatic rate and most have not yet metastasized at the time of amputation and diagnosis. In addition to chest radiographs prior to surgery, local lymph node aspiration for cytology during surgery is important in order to help assess prognosis.

What distinguishes lymphoma from leukemia?

A - Lymphoma originates in solid tissues
B - Lymphoma occurs only in dogs
C - Lymphoma is benign
D - Leukemia is the precursor to lymphoma
E - Leukemia is derived only from myeloid cells

Lymphoma originates in solid tissues. In general, lymphoma and leukemia both arise from malignant transformation of lymphoid cells and are named based on tumor location. Lymphoma=solid organs and bone marrow. Leukemia=blood circulation and bone marrow. Leukemias can also arise from myeloid cells (monocytes, basophils, eosinoiphils, megakaryocytes, erythrocytic precursor cells).

Lymphoma is a tumor of lymphocytes that originates mainly in solid lymphoid tissues including the bone marrow, thymus, lymph nodes, and spleen. In addition, common extranodal sites include the skin, eye, CNS, testis, and bone. Lymphomas are further distinguished according to their location (multicentric, cutaneous, CNS, GI).

Leukemia is a malignant neoplastic disease of the WBC or RBC precursors with neoplastic cells in the bone marrow and peripheral blood. Leukemias are further distinguished according to their behaviour (acute or chronic) and their precursor cell (lymphoid or myeloid), so you will see names like Acute Lymphocytic Leukemia (ALL) or Chronic Myeloid Leukemia (CML).

In cats, FeLV infection is an important risk factor for both leukemia and lymphoma. FIV infected cats have a higher than expected incidence of FeLV-negative lymphomas.

A five year old neutered male dog is presented with a raised 2 cm alopecic dermal mass on the lateral right hock, present for several months. A fine needle aspirate and cytology reveals a monomorphic population of round cells with dark blue staining intracytoplasmic granules.

Based on the presumptive diagnosis, what is the best choice for a treatment plan?

A - Itraconazole
B - Fluocinolone
C - Wide marginal excision
D - Benign neglect
E - Doxycycline

Wide marginal excision. Think of mast cell tumors when you see round cells with intracytoplasmic granules on a fine-needle aspirate. Follow this link to see mast cell cytology.

Wide marginal surgical excision offers the best chance for a cure of mast cell tumors especially if the cell type is well differentiated, if margins are clear and there is no evidence of spread to local lymph nodes. The location of the mass on the lateral hock is a challenge in this case, because it may not be possible to make wide and deep margins without skin grafts or healing by second intention.

Benign neglect is an excellent treatment option for masses confirmed on cytology to be cutaneous histiocytoma (pleomorphic round cells with clear blue cytoplasm-no granules). Histiocytomas are benign and usually resolve on their own within three months.

Doxycycline is an antibiotic often used to treat tick-borne diseases. In acute Ehrlichia canis infections, light blue intracytoplasmic inclusion bodies, morulae, may rarely be found within peripheral white blood cells.

Itraconazole is an antifungal drug used treat infections such as Aspergillosis, Cryptococcus, blastomycosis, histoplasmosis and coccidiodomycosis. In these cases, cytology would demonstrate dark staining fungal elements (hyphae, sperules, etc) extracellularly, and these elements would be much larger than the cells themselves.

An otherwise healthy rabbit that keeps shaking his head and scratching incessantly. There is a brown crust coating the interior of both ears.

What is the most likely diagnosis?

A - Psoroptes cuniculi
B - Otodectes cyanotis
C - Taenia serialis
D - Cheyletiella
E - Sarcoptes scabei

This is the ear mite Psoroptes cuniculi, extremely common in rabbits worldwide. Click here for an image. The mites irritate the ear which causes serum and brown crusts to accumulate.

Untreated infestations can cause secondary infections which can damage the inner ear. The crust can be cleaned with cotton soaked in dilute hydrogen peroxide, animal must be restrained or anesthetized for procedure. Mitacides approved for dogs and cats can be used, treat the inner ear plus the head and neck. SC ivermectin has been shown to be effective.

Cheyletiella, also called walking dandruff, is a fur mite also common in rabbits.

Sacroptes mange is rarely seen in rabbits, much more common in other animals, such as dogs and cattle.

Taenia serialis is a rare larval worm infestion in rabbits.

Several sheep aged 1-2 years in a herd of 300 were observed lagging and acting depressed in late summer. This morning, two animals found in sternal recumbancy died within hours.

On necropsy of one animal, the skin appears bruised and blackened due to extensive capillary rupture subcutaneously.

The pericardial sac is filled with straw-colored fluid and there is excess fluid in both the thoracic and peritoneal cavities. The liver has grayish yellow, necrotic foci and flukes.

What is the diagnosis?

A - Clostridium hemolyticum
B - Blackleg
C - Infectious necrotic hepatitis
D - Tyzzer's disease
E - Bacillary hemoglobinuria

Infectious necrotic hepatitis (Black disease) is the result of both Clostridium novyi and liver flukes.

When sheep eat spores of C. novyi on contaminated pasture soil, latent spores ultimately become lodged in the liver. The spores multiply in areas of liver necrosis caused by migration of liver flukes like Fasciola hepatica and Fascioloides magna.

C. novyi produces a lethal necrotizing toxin that kills sheep and occasionally cows and pigs.

A male gerbil is presented with a distinct oval area of alopecia on the mid-ventral abdomen. The animal has been observed rubbing this area on objects around its' terrarium.

What is the most appropriate interpretation?

A - Demodex meriones infestation, treat with ivermectin
B - Normal, do nothing
C - Trichophyton mentagrophytes, do a fungal culture
D - Sarcoptic mange, do a skin scrape
E - Common site of mammary gland adenocarcinoma, biopsy can confirm

This is the normal location of the ventral marking gland (or pad) in gerbils. It is normal and more pronounced in males than females.

Gerbils are often seen rubbing this area on things. This rubbing is thought to be a form of territorial marking.

Demodex meriones occurs occasionally in older, debilitated gerbils.

A 5-year old Arabian mare expels the placenta 2 hours after foaling.

On examination, it appears that the placenta has passed "inside out", with the allantoic side of the allantochorion exposed.

What is the correct interpretation?

A - Suggests premature placental separation
B - Foal at risk for peripartum asphyxia
C - Normal finding
D - Do not rebreed this mare
E - Sign of placental insufficiency

It is normal for a horse to expel the placenta "inside out", with the allantoic side of the allantochorion exposed.

Following parturition, the placenta should be expelled within 3 hours, or it is considered retained in the horse.

Which one of the following choices is the best post-mortem diagnostic test for scrapie in sheep?

A - Immunohistochemistry of the third eyelid
B - Skin biopsy of scraped area
C - IFA test on whole blood
D - ELISA antibody test on serum
E - Histopathology of the obex

Histopathology of the obex is the post-mortem test of choice for scrapie.

Immunohistochemistry of the nictitating membrane, though NOT 100% sensitive, can detect scrapie in live animals. A rectal mucosa biopsy test was approved by USDA APHIS in 2008 which is less time-consuming to perform and can be repeated.

Immuno-blot testing of biopsied tonsils may detect prion proteins in subclinically-infected sheep less than 1 year old. Antibodies against scrapie/prions are NOT produced.

When you think of Scrapie, remember also Bovine spongiform encephalopathy (BSE;cows) and Chronic Wasting disease (CWD; deer, elk).

All of these are REPORTABLE.

A mare has a waxy deposit on the end of each teat. What is the most likely explanation?

A - Recently bred
B - Precursor to mastitis
C - Normal sebaceous plug
D - About to go into labor
E - Signals LH surge and beginning of estrus

Waxing teats mean the mare is about to foal. "Waxing" happens in about 95% of mares 6 to 48 hours before foaling.

In the final two to three days of pregnancy, the teats of most mares distend with colostrum.

Colostrum drips and dries on the nipples to make a waxy coating at each teat orifice.

Which one of the following choices is the mechanism of action of omeprazole?

A - ?-Adrenergic receptor agonist
B - Cyclooxygenase blocker
C - H2-receptor antagonist
D - Synthetic prostaglandin E1 analog
E - Proton pump inhibitor

Omeprazole is a proton pump inhibitor that decreases gastric acid secretion. Omeprazole inhibits the sodium/potassium proton pump at the luminal surface of parietal cells. Parietal cells normally secrete hydrogen ions nto the stomach, a key component of acidic HCL.

Other drugs that decrease gastric acid secretion include the H2-receptor antagonists cimetidine, ranitidine, and famotidine and a synthetic prostaglandin E1 analog called Misoprostol.

Carprofen, Etodolac, Deracoxib, Meloxicam and Firocoxib are all nonsteroidal anti-inflammatory drugs (NSAIDS) that may CAUSE gastric acid secretion.

What are ongoing losses in fluid therapy?

A - The tears I shed when I can't make sense of fluid calculations
B - Percent dehydration multiplied by body weight
C - Vomit and diarrhea
D - Urine output
E - Fluids given minus extracellular volume estimate

Ongoing losses are typically vomiting, diarrhea or other losses into a third compartment (pleura, abdomen etc). These are sometimes called "contemporary" losses. A classic example of a disease with significant ongoing losses is a puppy with parvovirus who has both diarrhea and vomiting.

Sensible losses are easily measured, like the fluids the animal loses by urination.

Insensible losses are the fluids an animal loses that are hard to measure, through breathing and via the skin. In humans and animals that sweat (like horses) sweating is part of insensible losses.

Remember that all three types of loss must be accounted for (or at least estimated) when calculating fluids needed to rehydrate a dehydrated animal.

Which one of the following choices is the most appropriate treatment for the male guinea pig seen in this image?

[Ringworm (Trichophyton), guinea pig. Dermatophyte infections on the guinea pig are often located on the face, back, or front feet]

A - Fipronil SQ
B - Ivermectin SQ
C - Amitraz dips, once weekly
D - Griseofulvin PO
E - Penicillin G IM

The preferred answer is griseofulvin. This is ringworm in guinea pigs, which is usually self-limiting with good husbandry and sanitation.

Treat isloated lesions with topical miconazole, griseofulvin or butefanine.

Systemic treatments include fluconzole or griseofulvin. Remember that griseofulvin is teratogenic and must not be given to pregnant females.

Avoid fipronil and penicillins in guinea pigs. Amitraz is used against demodectic mange, not ringworm.

What is the proper name for this parasite of pigs?

Migrating swine kidney worm.]

A - Dioctophyma renale
B - Stephanurus dentatus
C - Trichinella spiralis
D - Capillaria plica
E - Gnathostoma spinigerum

This is Stephanurus dentatus, the swine kidney worm. These large worms (2-4.5 cm long) can be found encysted in pairs along the ureters from the kidney to the bladder.

Found worldwide, particularly in tropical and subtropical areas. Seen in the U.S. as a parasite of pigs raised outside in the southeastern and southcentral states.

What is a dysmature foal?

A - Born pre-term with ciliary dyskinesia
B - Born post-term, normal axial skeletal size but emaciated
C - Born pre-term, but with paradoxically normal respiratory function
D - Born to mare that ate endophyte-infested fescue
E - Born post-term but small

Dysmature foals are born post-term but small. Also called "small for gestational age", these foals are thought to have suffered placental insufficiency in-utero.

A postmature foal is a post-term foal that with normal axial skeletal size but is thin to emaciated. Most commonly born to mares ingesting endophyte-infested fescue.

Gestation length in mares ranges from 310 days to more than 370 days.

What is a gilt?

A - Female pig that has had more than one litter
B - Female pig that has not had a litter yet
C - A male pig, castrated before puberty
D - Ewe that has lambed at least once
E - Castrated male sheep

A young female pig that has not had a litter yet is called a gilt

A male pig, castrated before puberty is called a barrow

A wether is a castrated male sheep.

FYI-A female ferret is called a Jill and a male is called a Hob

How long is a practice required to maintain client medical records?

A - Decades
B - Weeks
C - Years
D - Months
E - Never

The exact amount of time you must preserve medical records varies by state and provincial law, but it is measured in YEARS, usually 4-6 years or so.

The number of years is typically based on the statue of limitations in your state or province for bringing certain claims against veterinarians.

In the state of Michigan for example, claims include general professional malpractice (2 years), negligence (3 years), property damage (3 years) and breach of contract (6 years).

Retained placenta and metritis can predispose to which one of the following secondary conditions?

A - Contagious equine metritis
B - Postpartum dysgalactia syndrome
C - Cystic endometriosis
D - Laminitis
E - Colic

In horses, retained placenta and septic metritis can cause acute laminitis.

Other causes of equine laminitis include:
Grain overload
Overeating on lush, high-protein Spring grasses
Exposure to black walnut (Juglans nigra) shavings
Over-exercise on hard surfaces and
Lameness on one limb requiring overdependency on opposite leg, which then develops laminitis.

This is a corneal abscess secondary to infectious keratoconjunctivitis (pinkeye).

What is the most commonly recognized organism that causes pinkeye in COWS?

A - Colesiota conjunctivae
B - Chlamydophila pecorum
C - Moraxella bovis
D - Mycoplasma spp
E - Neisseria spp.

In cattle, Moraxella bovis is the most commonly recognized cause of infectious keratoconjunctivitis, ("Pinkeye"); Other causes include Mycoplasma spp and Neisseria spp. The severity of infection with Moraxella bovis may increase with infection with IBR or other microbes. Chlamydophila pecorum is the most common cause of pinkeye in sheep.

Which one of the following choices includes the cardinal sign of trigeminal neuritis?

A - Dysphagia, dysphonia and stridor
B - Inability to close the mouth
C - Circling and head tilt toward side of lesion, no other signs
D - Masseter muscle pain associated with chewing
E - Paralyzed eyelid, ear or lip on one or both sides of the face

Idiopathic trigeminal neuritis, cranial nerve 5, (CN 5) is characterized by acute onset of flaccid jaw paralysis. Affected animals cannot close their mouth and have difficulty eating and drinking. Seen occasionally in dogs, rare in cats. Cause is unknown.

Idiopathic facial nerve paralysis, cranial nerve 7, (CN 7) results in the inability to move the eyelid, lip, or ear and dryness of the eyes and mouth.

Masticatory myositis is characterized by pain on opening the mouth and swelling of the muscles of mastication (acute) or atrophy of the temporalis and masseter muscles with the inability to open the mouth due to fibrosis (chronic).

Dysphagia, dyphonia, and stridor are most often associated with dysfunction of the vagus nerve, cranial nerve 10 (CN 10).

Circling and head tilt toward the side of the lesion with no other signs is a common presentation of vestibulocochlear nerve, cranial nerve 8 (CN 8) lesions. Concurrent CN 7 paralysis and Horner's syndrome (ptosis, miosis, enophthalmis) may be present with middle- and inner-ear infections.

A 2 day old pup has a GGT level of 500 times the adult upper reference range. Which one of the following choices is the most likely interpretation?

A - Due to colostrum absorption
B - Caused by traumatic placental detachment
C - Associated with bone development
D - Associated with neonatal cholestasis
E - Suggestive of a congenital a liver shunt

Very high GGT levels are seen with colostrum absorption

In newborn pups, lambs, and calves, an increase in GGT up to 1000 times is normal when they receive high levels of colostrum from the dam.

High levels of GGT are produced in the mammary epithelium during lactation. When evaluating bloodwork, reference ranges specific for the age of the patient should be utilized.

A 2 year old Angus cow presents with weakness of the hind limbs and a staggering gait. On physical exam, the heart rate and respiratory rate are slow and irregular, and the pupils are dilated. The cow's breath and urine smell like the odor of mouse urine.

Suddenly the cow's pulse becomes rapid and thready, she collapses, and dies of apparent respiratory failure.

Which one of the following plants is most likely to have caused this spectrum of clinical signs?

A - Pinus ponderosa (Western yellow pine)
B - Conium maculatum (Poison hemlock)
C - Veratrum spp (False hellebore, Skunk cabbage)
D - Centaurea spp (Knapweed, Yellow star thistle)
E - Tetradymia spp (Horsebrush)

Poisoning with Conium maculatum (Poison hemlock) is responsible for the death of this cow.

At least 8 toxic piperidine alkaloids have been isolated from poison hemlock . Coniine is found in seeds and the mature plants; g-coniceine is found in young growing plants.

Poison hemlock is toxic to all livestock and humans. Signs of toxicity develop 1-2 hours after ingestion and are usually fatal.

Signs include nervousness, trembling, weakness especially of the hind limbs, weak pulse, irregular heart rate, recumbency, coma and death. A mousy odor exuding from the urine and breath is pathognomonic.

Ingestion of Poison hemlock during gestation causes arthrogryposis and other congenital defects in cattle, goats, and pigs.

In which respiratory virus infecting horses is antigenic drift most important in the development of novel strains?

A - Equine influenza virus
B - Equine papillomavirus
C - Equid herpesvirus-4
D - Equid herpesvirus-1
E - Equine adenovirus

Antigenic drift is most important in the epidemiology of equine influenza.

Point mutations in the genes for hemagglutinin and neuraminidase cause changes in these surface proteins that can lead to the development of new virus strains not recognized by antibodies to earlier strains.

Because influenza is an RNA virus without proofreading ability, mutations can occur more rapidly with flu than mutations seen in DNA viruses like equid herpesviruses and adenoviruses.

What condition is associated with rectal stricture in pigs?

A - Intestinal spirochetosis
B - Intussusception
C - Coccidiosis
D - Rotavirus
E - Salmonella typhimurium

Salmonella typhimurium is associated with rectal strictures in growing pigs. Caused by an ulcerative proctitis that damages rectal tissue. Can see large numbers of cases. Can see sporadic rectal strictures as a sequelae to rectal prolapse. Follow this link to see a Merck image of rectal prolapse in a sheep.

Intestinal spirochetosis is a post-weaning diarrhea seen in the ABSENCE of Brachyspira (Serpulina) hyodysenteriae (swine dysentery), but similar in presentation to it. This syndrome is being recognized more frequently worldwide.

A bovine diet that is low in thiamine or high in sulfur can cause ____________.

A - Pregnancy toxemia
B - Polioencephalomalacia
C - Downer cows
D - Pseudorabies
E - Parturient paresis

The two most common causes of polioencephalomalacia (PEM) are low thiamine (due to thiaminase activity from plants like bracken fern or low thiamine diets) and high sulfur in the diet (which can come from a high molasses-urea diet, corn or sugar cane byproducts, water, or other plants, including alfalfa, Canada thistle (Cirsium arvense), kochia, (Kocchia scoparia), and lambsquarter (Chenopodium spp).

A postpartum down cow is being treated for Milk fever with a slow IV of Calcium gluconate.

During treatment, the heart is ausculted and pulses in the facial artery are monitored.

What changes are expected as the treatment progresses?

A - Arrhythmia changing to steady rhythm
B - Tachycardia slowing to bradycardia, pulse strength about the same
C - Bradycardia, weak pulse, changing to tachycardia, +/- arrhythmia
D - Tachycardia, weak pulse slowing to bradycardia, strong pulse
E - Bradycardia, weak pulse, speeding up to tachycardia, strong pulse

Expect TACHYCARDIA, WEAK PULSE in cows with milk fever. As you Rx with Ca gluconate, expect heart to SLOW down, and pulse strength to INCREASE.

CAUTION!! Calcium IV is CARDIOTOXIC!!! Too much Ca too fast will causes arrhythmias and even cardiac arrest!

A 2-year old heifer is presented who died the night before.

She was stunted compared to her herdmates, and had a 3-week history of poor appetite, unthriftiness, diarrhea.

Necropsy reveals that the abomasum is edematous and covered in small umbilicated nodules 1-2 mm in diameter (cobblestone or "Moroccan leather" appearance).

Several other younger cows in this Spring-calving herd look unthrifty and have diarrhea too.

What is the plan of action?

A - Cull the sick cows, Keep horses off same pasture 3 months
B - Treat affected heifers with Albendazole
C - Treat affected heifers with Ivermectin, repeat in 6 months
D - Treat herd with Amprolium, repeat q 5 weeks
E - Deworm cows post-calving, calves by midsummer, all stock in fall

Treatment includes deworming cows post-calving, calves by midsummer, all stock in fall. An abomasum with a cobblestone or "Moroccan leather" appearance is pathognomonic for Ostertagia, one of the three stomach worms of cattle. Follow this link to see a Merck image of Ostertagia in an abomasum. These worms remain dormant in the gastric glands of the abomasum, emerging in the spring.

Rx is based on regular deworming of whole herd (2-4 times/year). Ivermectin or high dose Albendazole/Fenbendazole, given repeatedly can help treat the dormant ("hypobiotic") Ostertagia in the gastric glands.

Amprolium is your treatment of choices for calves and cows with Coccidiosis.

Which three diseases are on the differential diagnosis list when encountering sudden death in a young, fast-growing calf?

A - Lasalocid toxicity, Salmonellosis, Lymphosarcoma-juvenile form
B - Bovine Viral Diarrhea, Lasalocid toxicity, White muscle disease
C - White muscle disease, Enterotoxemia, Colibacillosis
D - Winter dysentery, Enterotoxemia, IBR-encephalitic form
E - Salmonellosis, Colibacillosis, Enzootic Calf Pneumonia

When you hear "Sudden Death" in calves, think White Muscle Disease caused by Selenium/vitamin E deficiency; Think Enterotoxemia caused by Clostridium perfringens type C. And think Severe Colibacillosis. Can also see sudden death with encephalitic form of IBR and severe Salmonellosis.

A 2-month old calf is presented that was found dead.

The night before this calf was weak, feverish and had a mucoid brown diarrhea with a small amount of blood and a nasty odor.

Necropsy reveals a pseudo-diptheritic membrane lining parts of the distal small bowel and large bowel.

What is the diagnosis?

A - Salmonellosis
B - Coccidiosis
C - Ostertagiasis
D - Cryptosporidiosis
E - Bovine Viral Diarrhea, mucosal form

If you see "pseudo-diphtheritic membranes" in the intestines, think Neonatal salmonella. Look also for fever, diarrhea, especially with a "Septic tank odor" and systemic signs like septicemia, pneumonia, meningitis. Can die suddenly without diarrhea.

Other rule outs for OLDER calf diarrheas include:

Coccidiosis ( Older than 21 days and in ALL ages, bloody diarrhea, tenesmus)

Ostertagiasis (anorexia, poor growth, diarrhea in less than 2 year olds on pasture- a chronic disease)

BVD (Young cattle 6-24 mos, with mucosal lesions, diarrhea)

Winter dysentery (explosive outbreak watery diarrhea with clotted dark blood, stabled animals, all ages in winter) and

Johne's disease (Intractable diarrhea, cachexia).

Crypto is typically a disease of the young, 1-4 weeks old.

A 2-week old calf is presented that is dehydrated and almost emaciated from weight loss. She has a 1 week history of watery, foamy diarrhea and exhibits tenesmus during examination.

The calf is the only sick one in a mixed group of calves that range from 3 weeks to 2 months of age

What is the diagnosis?

A - Coronavirus
B - Coccidiosis
C - Colibacillosis
D - Ostertagiasis
E - Cryptosporidiosis

Watery diarrhea in a SINGLE animal (1-4 weeks) in a group, plus emaciation suggests Cryptosporidiosis.

Expect a more acute, lethal presentation of hemorrhagic diarrhea in 1-4 DAY old calves with Colibacillosis, and multiple cases with the viral diarrheas like Rotavirus - (5d-2 wks old, self limiting); Coronavirus, (4-30d).

OLDER-animal diarrheas on this list include Coccidiosis ( Older than 21 days and in ALL ages, bloody diarrhea, tenesmus) Ostertagiasis (anorexia, poor growth, diarrhea in less than 2 year olds on pasture- a chronic disease).

At what age do a cow's permanent canine teeth begin to erupt?

A - 3 years
B - Cows don't have canines
C - 3.5 to 4 years
D - 2 to 2.5 years
E - 5-6 years

3.5 to 4 years. Cows DO have canine teeth but they look like incisors. Permanent canines erupt at around 4-5 years in cows.REFERENCES VARY by about 6 months, because the times of tooth eruption also vary among different individual animals.
1st permanent incisors (I1-centrals) erupt at 1 to 1.5 years
2nd permanent incisors (I2-medials) erupt at around 2 to 2.5 years
I3-laterals erupt at roughly 3.5 years.
Permanent canines (which look like a 4th set of incisors in ruminants) come in around 3.5 to 4 years.
FULL eruption of a new tooth may take another 6 months.

One reference, (Pasquini) suggests this approximate, but easy-to-remember rule of thumb for FULLY erupted permanent incisors in cows: I1-2 yr, I2-3 yr, I3-4 yr

This 3 year old Charolais bull weighing 2100 lbs was found at pasture walking in circles. He has been fed silage enriched with 5% dried chicken litter in addition to the winter pasture.

Physical examination findings include
T = 104.6°F (40.3°C)..[N=101.5-103.5 F]
Pulse rate = 46 beats per minute....[N=55-80bpm]
Resp. rate = 21 per minute....[N=10-30 brpm]

He is depressed, anorectic and drooling, with a head tilt to right. The right ear and eyelid both droop. The bull is ataxic with predominantly right sided proprioceptive deficits.

A sample of cerebrospinal fluid (CSF) taken at the lumbosacral space has normal color, no turbidity but has an increased mononuclear cell count and an elevated protein concentration.

Which one of the following choices is the most likely diagnosis?

A - Otitis media/interna
B - Rabies
C - Nervous coccidiosis
D - Listeriosis
E - Thromboembolic meningoencephalitis

Listeriosis is most likely in this bull. Infection with Listeria monocytogenes usually presents with MULTIFOCAL brainstem signs as seen by dysfunction of multiple cranial nerves, most often V, VII-X, and XII.

Circling is thought to be more than just CN VIII damage because of the intensity associated - affected animals will sometimes continuously circle till they collapse. This suggests that other areas of the brain such as the basal ganglia and the descending reticular formation are also affected.

Thromboembolic meningoencephalitis (TEME) causes brainstem and cerebellar signs but the CSF would be neutrophilic and xanthochromic. The xanthrochromia is due to vasculitis/thrombosis in the CNS. TEME is more common in feedlot calves; respiratory disease, septicemia, and joint disease may also be seen.

Animals with otitis media/interna are alert and responsive, and have signs of vestibular dysfunction, but are not paretic.

The bull could have rabies, but the multifocal nature of this bull's problem and the localization of lesions to the brainstem favor a diagnosis of listeriosis.

Patients with nervous coccidiosis are usually centrally blind, and have cerebral rather than brainstem signs. It is most often seen in calves soon after the development of diarrhea.

What kind of organism causes Equine granulocytic ehrlichiosis?

A - Protozoa
B - Chlamydia
C - Erhlichia
D - Spirochete
E - Anaplasma

This is a tricky question to help you remember that two diseases FORMERLY classified as ehrlichia have now been re-classified. The causative organism of Equine granulocytic ehrlichiosis (EGE) was originally classified as Ehrlichia equi, but is now called ANAPLASMA phagocytophila due to DNA sequencing studies.

Do not confuse EGE, a necrotizing vasculitis in HORSE with BOVINE anaplasmosis, primarily an anemia, with icterus, fever.

Another name change occurred with the causative organism of Potomac Horse Fever (PHF), from Ehrlichia risticii to NEOrickettsia risticii. PHF presents as a febrile colitis/diarrhea, with laminitis 3-5 d after diarrhea in horses of all ages: A big rule out is salmonella (think septicemia/fever+ diarrhea).

A mare presents with a history of herding and mounting other mares in a broodmare group. During the physical exam, the mare is very unruly and tries to bite and kick.

After sedation, rectal palpation findings reveal a walnut sized, smooth left ovary and a softball sized right ovary. No ovulation fossa is palpable on the right ovary.

Which one of the following choices is the most likely diagnosis for the right ovary?

A - Granulosa cell tumor
B - Cystic ovary
C - Anovulatory follicle
D - Transitional status
E - Hematoma

Granulosa cell tumors (GCTs) secrete reproductive hormones such as testosterone, inhibin, and estrogen. Testosterone causes the mare to show stallion-like behavior, while estrogen causes persistent estrus

Approximately 50-90% of mares with GCTs have elevated testosterone and over 85% of mares with GCTs have high inhibin.

With GCTs the contralateral ovary tends to stop producing follicles and resembles an ovary during anestrus.

Thi calf was aborted at 7.5 months pregnancy in early fall. The dam was a primiparous beef animal housed on pasture in Northern California.

Necropsy revealed multiple petechial hemorrhages on the palate and scleral mucus membranes of the fetus, and marked lymphadenopathy. The calf was not decomposed; the cow retained the placenta.

Image courtesy Dr. Lisle George copyright 2012

Which one of the following choices is the most likely diagnosis of the abortion in this case?

A - Brucella abortus
B - Neospora caninun
C - Leptospira pomona
D - Pine needles
E - Foothill abortion agent

This is a typical case of foothill abortion, also called Epizootic Bovine Abortion. The condition is common in the coastal and Sierra Nevada foothills, and throughout much of the western United States. It is the most common cause of abortion in California beef cattle.

The etiologic agent has not been identified with certainty. Research suggests that it is a delta protobacteria with DNA homology to bacteria of the vibrio genus. Pregnant cattle exposed to thymic tissues from aborted fetuses can be protected from abortion by feeding tetracycline through the early stages of pregnancy.

The agent is transmitted by the soft shelled Pajahuello tick (Ornithodorus coriaceus). The disease occurs predominantly in heifers. Infection develops during the first trimester of pregnancy while abortions occur later around the 5th to 9th month.

Exposed cattle develop immunity, but it is not known how long protection lasts. However, abortion does not often recur in these animals. The presence of petechial hemorrhages and lymphadenopathy in a late-term aborted fetus is suggestive of foothill abortion.

Neospora is another common abortifacient of beef cattle, but does not produce lymhadenopathy or petechiae in the fetus. Leptospirosis, brucellosis, and pine needles also do not produce the same pathologic lesions as the foothill agent.

An obese 6 year-old neutered male Pomeranian presents with a 2-year history of intermittent dry, honking cough. This morning he started retching. The dog never boards in a kennel and has not traveled recently.

On physical exam, a cough can be elicited by pressing on the trachea. A heart murmur is noted, loudest on the left at the 5th-6th intercostal space. The rest of the exam was unremarkable.

T=102.2 F (39 C)..[N=99.5-102.5 F]
HR=120 bpm .......[N=80-120]
RR=80 brpm .......[N=15-34]
CRT=2 sec...........[N= less than 2 sec], MM=pink

What diagnosis is at the top of the differential list?

A - Congestive heart disease
B - Chronic bronchitis
C - Tracheal obstruction
D - Tracheal collapse
E - Tracheobronchitis

When you hear a "HONKING COUGH" and heart murmur in a fat little dog that coughs after touching his tracheal area, think tracheal collapse. Toy/Min. breeds (Pomeranians, Toy poodle, Min. poodle, Yorkies) are predisposed.

Mitral insufficiency / dysplasia murmurs are often detected concurrently.

Intermittent hx and lack of fever suggest a chronic, non-infectious cause. For definitive diagnosis do thoracic radiographs, bronchoscopy.

Which disease of rabbits is reportable?

A - Encephalitozoonosis
B - Treponematosis
C - Tularemia
D - Myxomatosis
E - Rabbit (Shope) Fibroma Virus

Tularemia is a disease primarily of wild rabbits caused by Francisella tularensis. Up to 90% of human tularemia cases are linked to wild lagomorph exposure. Tularemia is a Category A bioterrorism agent. REPORTABLE.

Treponematosis (rabbit syphillis, vent disease) is a venereal disease of rabbits caused by Treponema paraluis cuniculi. Click here to see a rabbit with cutaneous treponematosis

Myxomatosis ("big head") is a fatal disease of domesticated rabbits caused by myxoma virus, characterized by mucinous skin lesions or "myxomas".

Encephalitozoonosis is a protozoal disease caused by Encephalitozoon (Nosema) cuniculi. Typically does not cause illness in rabbits, but is an emerging disease of immunosuppressed humans.

A 3-year old Irish Setter presents with a history of lameness and swelling in the distal forelimb. A radiograph looks like the image below.

What is the presumptive diagnosis?

Click here to see image

A - Osteochondrosis
B - Hypertrophic osteodystrophy
C - Panosteititis
D - Osteomyelitis
E - Osteosarcoma

This is a classic image of Osteosarcoma, a COMMON, aggressive bone tumor typically found in the appendicular skeleton, especially distal radius.

90% have microscopic metastases to lungs by time of Dx, (but less than 10% will have visible thoracic metastasis at time of diagnosis).

Usually, does not cross joint (unlike osteomyelitis, which usually DOES cross joint). Look for soft tissue swelling, periosteal proliferation, sunburst periosteal reaction (33%), possible pathologic fractures.

Which one of the following drugs is used primarily to treat pituitary-dependent hyperadrenocorticism (Cushing's disease) in dogs?

A - Phenoxybenzamine
B - Liothyronine
C - Imidocarb
D - Mitotane (o,p DDD)
E - Fludrocortisone acetate

Mitotane (o,p DDD) is used to treat pituitary-dependent hyperadrenocorticism (Cushing's disease). Mitotane selectively destroys the glucocorticoid-secreting cells of the adrenal cortex.

REMEMBER dogs undergoing mitotane therapy should receive supplementary glucocorticoids when undergoing stress (ie: surgery, trauma, acute illness).

Alternative treatments include l-Deprenyl (decreases pituitary ACTH secretion) or Ketoconazole (inhibits enzymes of cortisol synthesis, may be used in dogs who do not tolerate Mitotane).

NOTE Trilostane, a drug is also used in treatment of hyperadrenocorticism. Survival times appear to be similar between Trilostane and Mitotane.

Trilostane is typically given SID to BID lifelong, while maintenance Mitotane is typically given 2-3 times per week. Long-term, Trilostane is more expensive than Mitotane.

Trilostane appears to be safer in general but patients must be monitored for adrenal necrosis, which can lead to Addisonian crisis and death if unrecognized. Experienced practitioners may disagree on whether to use Trilostane vs. Mitotane.

Which one of the following antibiotics is the treatment of choice in the face of a vibriosis abortion storm?

A - Tetracycline
B - Fluoroquinolone
C - Chloramphenicol
D - Cephalosporin
E - Aminoglycoside


Long acting oxytetracyclines are effective against Campylobacter jejuni and C. fetus subsp fetus, the organisms that cause vibriosis. Daily dihydrostreptomycin or penicillin can also be used but is more labor intensive.

Chloramphenicol is prohibited in food animals.

A 12 year old neutered male cat is presented with a history vomiting, weight loss, increased drinking, polyphagia and recent urinary accidents in the house.

On physical exam, the patient is unthrifty and tachycardic with a moderate systolic heart murmur, loudest on the left.

T=102 F (38.8C)..[N=100-103.1F]
HR=172 bpm.......[N=130-140]
RR=38 bpm.........[N=16-40]

PCV=40 %.............[N=24-45%], WBC=14,810..[N=3800-19,500]

Blood chemistry
NA=157................[N=151-161], K=4.1..[N=3.5-5.1]
LDH=250...............[N=35-225], ALT=108..[N=8.3-53]
Total protein=6.2..[N=5.7-8.0], Glucose=140..[N=63-132]
Alk Phos=480.........[N=3-65], Cholesterol=110..[N=95-130]
BUN=42 mg/dL.......[N=10-30], Creatinine=1.9 mg/dL..[N=0.8-2.0 ]
Bilirubin (total)=0.2.[N=0.0-0.2]

U Sp. G= 1.017........[N=1.020-1.040]
Glucose none, WBC none, RBCs occasionally.

Which one of the following tests is most likely to confirm the diagnosis?

A - Fasting blood glucose
B - Serum total T4
C - Echocardiogram
D - ACTH stimulation test
E - Hepatic biopsy

Think of hyperthyroidism and a serum total T4 test for a middle-aged to older cat with clinical signs of weight loss, polyphagia, polyuria, polydipsia, and or poor grooming habits (ie: unthrifty).

Other signs include hyperexcitability and palpable enlargement of the thyroid gland. GI signs are common, including vomiting, diarrhea and increased fecal volume. Cardiovascular signs can include tachycardia, systolic murmurs, dyspnea, cardiomegaly, and congestive heart failure.

Clinical pathology findings may include a stress leukogram and mild erythrocytosis. Liver enzymes are commonly increased, particularly alkaline phosphatase. Urine specific gravity results vary.

The test of choice for hyperthyroidism is serum total T4 (TT4--measures protein-bound and free (unbound) T4), in conjunction with clinical signs.

The lesions of chronic Salmonella pullorum in poultry are indistinguishable from the lesions of which disease?

A - Fowl cholera
B - Samonella arizonae
C - Fowl typhoid
D - Samonella enteritidis
E - Coronaviral enteritis

In mature chickens, the lesions produced by chronic infection with Salmonella pullorum are indistinguishable from the lesions of fowl typhoid, caused by Salmonella gallinarum.

A number of older cows in a Texas herd are losing condition rapidly with a corresponding drop in milk production. Two pregnant animals have aborted.

Affected animals are off feed, uncoordinated and out of breath after exertion. On physical exam, affected cows have a rapid bounding pulse and pale mucous membranes. One animal appears icteric with a temperature of 105°F (40.6°C).

A blood smear looks like this: click here to see image

What is the most likely diagnosis?

A - Theileriosis
B - Leptospira icterohaemorrhagiae
C - Eperythrozoon spp.
D - Babesia bigemina
E - Anaplasmosis


Which two drugs are contraindicated in animals with history of seizures?

A - Acepromazine, ketamine
B - Xylazine, thiopental
C - Ketamine, diazepam
D - Morphine, phenobarbital

Acepromazine, ketamine, and xylazine are contraindicated in animals with a history of seizures.

Thiopental is contraindicated in animals with history of asthma, because it can cause apnea, and in Greyhounds. Morphine should not be used in cases of high intracranial pressure (like head trauma after being hit by a car). Diazepam and phenobarbital are drugs used to TREAT seizures.

STRATEGY HINT: This is a "frequency" question. That is, you can see how the choice "ketamine" is repeated, twice. Chances are that the correct choice will include the word that is repeated the most often. In this case, even if you have no idea what the right answer may be, simply narrowing down to the two answer choices that include ketamine will increase your chances of picking correctly to 50:50 !

A foal born 12 hours ago is observed swishing its' tail from side to side, straining with an arched back and rolling on the stall floor.

What test is indicated to rule in the presumptive diagnosis?

A - Ultrasound of umbilicus/urachus
B - Succussion of right caudal abdomen
C - Digital exam of rectum
D - Cystocentesis
E - Endoscopy of gastric mucosa

Digital exam of rectum. Foals with meconium impaction will swish their tail from side to side, roll, and strain to defecate. A digital exam of the rectum will aid in rapid diagnosis.

Meconium impaction is the most common cause of colic in the newborn foal, typically seen within 24 hours of birth. More common in colts (males) than fillies because colts have a smaller pelvis.

A commercial pig farm experiences an explosive outbreak of respiratory disease with high mortality, primarily in young pigs under 6 months of age.

Affected pigs show severe respiratory distress, fever up to 107°F (41.5°C), anorexia, and reluctance to move. Some animals display open-mouth breathing with a blood-stained, frothy nasal and oral discharge.

On necropsy, the lungs are bilaterally dark and swollen and ooze bloody fluid from the cut surface. Click here to see image

Which one of the following choices is the most likely diagnosis?

A - Mycoplasma hyopneumoniae
B - Swine influenza
C - Haemophilus parahaemolyticus
D - Actinobacillus pleuropneumoniae
E - Fusobacterium necrophorum

This is a classic scenario of an outbreak of pleuropneumonia, caused by Actinobacillus pleuropneumoniae.

Heat pasteurization of milk is done principally to prevent transmission of which one of the following organisms to people?

A - Mycobacterium avium subspecies paratuberculosis
B - Mycobacterium bovis
C - Mycobacterium avium
D - Enterotoxigenic Escherichia coli O157:H7
E - Mycobacterium tuberculosis

A century ago, Mycobacterium bovis (bovine tuberculosis) used to be a common zoonotic health threat, transmitted through milk to children through their emerging teeth at the gums.

Today, human cases of M. bovis are emerging more in binational communities with ties to Mexico who consume unpasteurized milk products (like fresh queso).

A 4-day-old foal is presented with clinical signs of depression, icterus, head pressing, and disorientation. Serum biochemistry reveals increased levels of gamma-glutamyltransferase, alkaline phosphatase, and unconjugated bilirubin.

On further questioning, the owner mentions that he gave the foal an oral nutritional supplement when it was a day old but was not sure what was in it.

What could this supplement have contained to cause these clinical signs?

A - Vitamin A
B - Vitamin E
C - Selenium
D - Iron
E - Copper

Neonatal foals given oral iron supplements at birth can develop toxic injury to their liver and subsequent hepatic encephalopathy.

Foals are born with a high serum iron level and absorb iron more readily than adult horses.

An adult horse with clinical signs of voluminous gastric reflux, depression, colic, and fever is most likely suffering from which one of the following choices?

A - Proximal enteritis
B - Ulcerative duodenitis
C - Proliferative enteropathy
D - Right dorsal colitis
E - Cantharidin toxicity

Proximal enteritis, or duodenitis-proximal jejunitis, is a clinical syndrome characterized by large volumes of gastric reflux resulting from excessive fluid and electrolyte secretion into the small intestine and small intestinal inflammation and edema.

Laminitis is an important potential sequela. The cause is unknown but several bacteria and toxins including Clostridium difficile, Clostridium perfringens, Salmonella, and fumonosin B1 mycotoxins have been implicated.

Ulcerative duodenitis is a disorder of foals resulting in fever, colic, diarrhea, and delayed gastric emptying. Lawsonia intracellularis causes proliferative enteropathy in foals and weanlings, a disease characterized by hypoproteinemia, diarrhea, chronic ill thrift, and ventral edema.

Right dorsal colitis is typically a result of non-steroidal anti-inflammatory drug toxicity and results in hypoproteinemia and colic.

Cantharidin toxicity (blister beetles, Epicauta spp.) causes a wide range of clinical signs predominated by profuse diarrhea, stranguria and pollakiuria, and colic.

Several younger sheep in a large herd have died suddenly with a diagnosis of infectious necrotic hepatitis secondary to fluke infestation.

Which one of the following choices is the most practical and effective control measure?

A - Clorsulon antihelmintic for whole herd
B - High-dose penicillin for clinical cases
C - Treat ponds with copper sulfate molluscicide against lymnaeid snails
D - Vaccinate all animals with Clostridium novyi toxoid
E - Clostridium hemolyticum bacterin for animals under 3 years

Active immunization with Clostridium novyi toxoid before the late summer is the most effective way to control and prevent Infectious necrotic hepatitis (Black disease) in sheep.

Because vaccinated sheep have long-term immunity after only one shot, only new introductions to the flock (lambs and sheep brought in from other areas) need to be vaccinated.

Reducing the number of snails (intermediate hosts for fluke cercaria) with molluscicides or by fencing off wet areas may not be practical due to expense or amount of pasture lost. Likewise, use of flukicides is complicated by the need for careful timing and long withdrawal times for meat and milk.

When a foal is being treated with erythromycin (for Rhodococcus equi for example), the mare is at risk of developing enterocolitis due to which one of the following organisms?

A - Lawsonia intracellularis
B - Clostridium difficile
C - Rhodococcus equi
D - Escherechia coli
E - Clostridium novyi

A history of recent antimicrobial therapy is common in cases of Clostridium difficile associated diarrhea. Adult horses exposed to erythromycin are particularly at risk for C. difficile enterocolitis.

Clostridium novyi is the cause of infectious necrotic hepatitis, which is primarily seen in sheep but can also be seen in cattle, hogs, and horses.

Lawsonia intracellularis is the cause of proliferative enteropathy, resulting in diarrhea and hypoproteinemia in foals and swine.

Rhodococcus equi is a notable cause of pneumonia in older foals characterized by pulmonary abscessation as well as some extrapulmonary manifestations.

Escherechia coli can be a cause of septicemia and diarrhea in foals and calves.

A 4-year old thoroughbred mare is presented with a sudden onset of profuse, watery diarrhea and marked depression.

The mare has been intermittently treated with phenylbutazone over the last 2 months for minor lameness and was transported by trailer for 9 hours recently.

On physical exam the horse is dehydrated, with slow capillary refill time, purplish mucous membranes and cold extremities.

T=100.0 F (37.8 C)..[N=99-101.3 F]
HR=48 bpm.............[N=28-40]
RR=32 brpm............[N=10-14]

The horse dies 3 hours later. On necropsy there is blood-stained fluid in the intestines and pronounced edema and hemorrhage in the wall of the large colon and cecum.

Which one of the following choices is the most likely diagnosis?

A - Sand enterocolopathy
B - Nonsteroidal anti-inflammatory drug toxicosis
C - Granulomatous enteritis
D - Parascaris equorum infestation
E - Colitis X

This is the clinical picture of colitis X, an acute to peracute-onset of lethal diarrheal disease of horses.

Look for shock signs, peracute severe diarrhea and a packed red cell volume (PCV) above 65%, and sudden death.

The cause is unknown but stress (like transport) or surgery often precedes disease.

This is a diagnosis of exclusion-if you rule out other peracute severe diarrheas (Salmonellosis, Potomac horse fever (PHF), Clostridial enterocolitis, Lincomycin/Tetracycline toxicosis), you are left with presumptive colitis X.

A three year old male neutered Weimaraner dog is presented with a two day history of worsening anorexia, lethargy, cough and exercise intolerance.

On physical exam, the mucous membranes are pale with a few petechiae.

T=99.8 F (37.7 C)..[N=99.5-102.5 F]
RR=24 brpm.....[N= 15-34]
HR=144 bpm....[N= 110-120]

A coagulation profile shows the following:

Thrombocytes= 343,500 per microliter..[N=200,000-900,000]
Buccal mucosal bleeding time (BMBT), normal
Activated partial thromboplastin time (aPTT), increased
Prothrombin time (PT), increased
Thrombin time (TT), normal
Fibrin degradation products (FDPs), normal

Which one of the following choices is the most appropriate diagnosis?

A - Neonatal isoerythrolysis
B - Idiopathic thrombocytopenia
C - Disseminated intravascular coagulation (DIC)
D - Anticoagulant rodenticide toxicity
E - Von Willebrand's disease

Anticoagulant rodenticide toxicity (or liver disease) can demonstrate increased activated partial thromboplastin time (aPTT) and prothrombin time (PT).

Sometimes a mild to moderate thrombocytopenia may occur (50,000-150,000/μl). Proteins induced by vitamin K1 absence or antagonism (PIVKA) will be prolonged. The PIVKA test is more sensitive than PT/aPTT but is not as widely available. A threefold increase in PT or PIVKA is supportive of anticoagulant rodenticide toxicosis.

Often there is no history of exposure to a rodenticide. Clinically, vague initial clinical signs like anorexia, lethargy and exercise intolerance may be the first manifestation of illness. With progression, you may see an acute hemorrhagic presentation.

Follow this link to see a table of the four most important coagulation disorder patterns

A cat with a previous diagnosis of diabetes mellitus confirmed by persistent fasting hyperglycemia and persistent glycosuria is presented for a routine check-up. The owner relates that she ran out of injectable insulin two months ago, but the cat seemed to do fine without it, so she stopped giving insulin shots.

On physical exam, the cat appears healthy and a dipstick test shows a blood glucose level of 125 mg/dL (normal 61-132 mg/dL)

What is the most likely explanation?

A - Incorrect initial diagnosis
B - Transient diabetes mellitus
C - Type I diabetes mellitus
D - Insulin resistance
E - Concurrent diabetes insipidus

20% of cats may have transient or subclinical diabetes mellitus characterized by resolution of the clinical weeks to months after beginning insulin treatment. Clinical disease may or may not recur in the future.

Non-insulin-dependent diabetes mellitus (type II) occurs in about 30% of cats at the time of diabetes diagnosis. There is a a reduced population of pancreatic Beta cells.

Cats with non-insulin-dependent diabetes mellitus may respond to a treatment regimen of weight loss, diet, oral hypoglycemic drugs, and correction of concurrent insulin antagonistic disease; that is, they can respond without injectable insulin.

Persistent fasting hyperglycemia (blood glucose greater than 200 mg/dL) and persistent glycosuria are confirmatory for diabetes mellitus, so "incorrect diagnosis" is a wrong answer choice in this case.

Several sheep are sick at a petting-zoo that has cows, horses, pigs, bison and white-tailed deer. One of the deer is also affected. Affected sheep are listless and off-feed, with serous or mucopurulent nasal discharge and rectal temperatures ranging from 105-107.5°F (40.5-42°C).

Physical exam shows swollen muzzles with edema and congestion of the lips, nose and face with small hemorrhages and ulcers on the mucous membranes. The ulcers appear where the teeth contact the swollen lips and tongue. Two affected sheep are lame.

What is the diagnosis?

A - Caprine arthritis encephalitis
B - Contagious ecthyma (soremouth)
C - Peste des petits ruminants (PPR)
D - Foot-and-mouth disease (FMD)
E - Bluetongue

Swollen sore muzzles with mucous membrane erosions, high fevers and lameness suggests infection with Bluetongue virus. Bluetongue is almost exclusively seen in sheep, though white-tailed deer, pronghorn antelope and desert bighorn sheep in North America can be severely affected. Rare in cows. REPORTABLE.

Bluetongue is indistinguishable from Foot and Mouth disease (FMD), so that is a good second choice. But FMD is unlikely in the scenario above because FMD mainly affects pigs and cattle.

A 4-year old quarterhorse presents with a 3 week history of diffuse patchy alopecia on the ventral midline and face, including a "bulls-eye" lesion in the center of the forehead.

There is a mild conjunctivitis and uveitis OU (both eyes). A punch skin biopsy looks like the image below. What is the most appropriate treatment?

A - Trichlorfon drench, antibiotic ophthalmic ointment TID
B - Do nothing
C - Ivermectin now, repeat in 4 months
D - Topical DMSO, Oxybendazole q. 8 weeks
E - Corticosteriods, benzimidazole-piperazine q. 12 weeks

The treatment of choice for Onchocerca spp microfilaria is an avermection-family drug, with retreatment at 4 month intervals.Treated horses show marked improvement. Although adult filaria are not killed by avermectins, in practice most horses are free of disease within 6-12 months.

Adult filaria live in calcified nodules in the ligamentum nuchae and produce microfilaria that migrate to the ventral midline, face, neck, and chest. The resulting dermatitis is thought to be a hypersensitivity to microfilarial antigens. Accumulation of microfilaria in the eye may also lead to conjunctivitis and uveitis.

Note that Culicoides spp (no-see-ums, biting midges) carry the onchocerca microfilariae, but do not cause the problems listed above themselves. Instead, biting midges cause sweet itch, a very pruritic warm weather dermatitis that is also secondary to hypersensitivity.

Doing nothing is a poor choice in this symptomatic animal. Finding microfilaria in skin biopsies of asymptomatic horses is a common incidental finding. Because of this, some references debate the role of onchocera in the pathogenesis. It seems likely that variations in immune response play a role in severity of disease presentation.

In humans, Onchocerciasis is a well known cause of hypersensitivity-related superficial keratitis (river blindness) and dermatitis.

Two blood samples are shown below from a 4-year old female spayed Doberman pinscher is presented with a 2-day history of progressive weakness and inappetence.

Physical exam shows icteric, pale mucous membranes and tachycardia.
What message should be communicated to the owner?

A - 50% of cases are heartworm positive
B - Many dogs relapse within a year
C - Zoonotic, may indicate tick-related problem
D - Infectious, need to check other dogs in house
E - Grave prognosis

Many dogs relapse within a year. This is the clinical picture of Immune-mediated hemolytic anemia (IMHA). Owners need to know that many dogs will relapse within a year and that chronic treatment and monitoring is indicated.

The basis of chronic therapy is based on immunosuppression (with prednisone, for example), on tapering doses for 3-6 months, as long as hematocrit is stable.

Dogs with IMHA usually die of anemia or thromboembolism. Mortality is estimated at 40-60%.

Be aware that thrombocytopenia, thromboembolism and disseminated intravascular coagulation (DIC) are three associated conditions to watch for in a dog with IMHA.

A 4-year old quarterhorse mare is presented with a runny left eye and a urine-scalded perineum. No other horses on the farm are sick. Physical exam reveals a corneal ulcer and keratitis OS (left eye), and atrophy of the temporal and masseter muscles.

There is decreased perineal sensation, a weak tail and weak anal sphincter with retained manure. The horse is bright, alert and responsive.
T=102.2 F (39.1 C)..[N=99.0-101.3 F]
HR=40 bpm............[N=28-40]
RR=12 brpm...........[N=10-14]

Which one of the following choices is the most likely diagnosis?

A - Equine degenerative myelopathy (EDM)
B - Equine protozoal myelopathy (EPM)
C - Nigropallidal encephalomalacia
D - Botulism
E - Cauda equina neuritis

Horses with Cauda equina neuritis (also called polyneuritis equi) have a progressive symetric LMN paresis of the tail, bladder, rectum, anal sphincter. Look for urinary incontinence, fecal retention and a weak or paralyzed tail. May see hind limb paresis if lumbosacral spinal cord is affected.

Cranial nerves can also be affected, but typically cranial involvement is asymetric. May see temporal or masseter atrophy (Cranial Nerve 5), facial paralysis and exposure keratitis (Cranial nerve 7), head tilt or other CNS signs.
Cause is unknown, may be an autoimmune process. Grave prognosis. Eventually euthanized.

Herpesvirus myeloencephalopathy (EHV-1) may also present with urinary incontinence, but this is an uncommon manifestation of equine rhinopneumonitis. You would expect to hear a history of the more common EHV signs in other horses from the same farm, like respiratory disease ("snots") in foals and abortions in mares.

A multiparous cow that calved two months ago is presented with a history of blood-stained urine for the last week. Today, the cow is off-feed and colicky, switching her tail restlessly and urinating frequently.

T=103.8 F (39.9 C)..[N=101.5-103.5 F]
HR=70 bpm.............[N=55-80]
RR=32 brpm............[N=10-30]

A cowside dipstick test shows hematuria and proteinuria. The bladder, ureters and left kidney feel grossly normal on rectal exam.

Which one of the following choices is the most likely diagnosis?

A - Polycystic kidney disease
B - Pyelonephritis
C - Leptospirosis
D - Pyometra
E - Dioctophyma renale

This is the clinical picture of a cow with early signs of pyelonephritis. Onset is typically insidious. The first clinical sign may be passage of blood-stained urine (hematuria) in an otherwise normal animal.

As infection (usually Corynebacterium spp or E. coli) ascends up the ureters into the kidney, the cow may display frequent attempts to urinate, anorexia, a slight fever, loss of production, colic, restlessness, tail switching, polyuria, more hematuria or pyuria.

Early in the disease, enlarged ureters and involvement of the kidney may not be detectable on rectal palpation. In chronic cases, the left kidney may be enlarged, with loss of lobulation and pain. The cow may show colic, diarrhea, polyuria, polydipsia, stranguria, and anemia.

The Animal Welfare Act is enforced by which U.S. government agency?

A - National Institute of Health (NIH)
B - Centers for Disease Control and Prevention (CDC)
C - Institutional Animal Care and Use Committee (IACUC)
D - Department of Agriculture (USDA)
E - Food and Drug Administration (FDA)

The United States Department of Agriculture (USDA) enforces the Animal Welfare Act.

Specifically, it is the Animal and Plant Health Inspection Service (APHIS) within the USDA that is responsible.

The Animal Welfare act sets minimal standards for care of laboratory animals including dogs, cats and non-human primates. It regulates the pet trade, animal transportation and exhibition and licensure of animal dealers. Since 1976 it has prohibited most forms of commercial animal fighting.

A dog that was treated for vomiting with metoclopramide is now displaying involuntary muscle spasms and inappropriate aggression.

Which one of the following choices is most appropriate to help reverse the adverse effects?

A - Yohimbine
B - Ace-promazine
C - Diphenhydramine hydrochloride
D - Telazol (tiletamine-diazepam combination)
E - Ketamine

Diphenhydramine hydrochloride. Metoclopramide crosses the blood-brain barrier, where dopamine antagonism at the medullary chemoreceptor trigger zone (CTZ) causes an antiemetic effect.

This dopamine antagonism can also cause adverse extrapyramidal signs, like involuntary muscle spasms, motor restlessness and inappropriate aggression. If recognized in time, extrapyramidal signs can be reversed by restoring the dopamine:acetylcholine balance with the anticholinergic action of an antihistamine like diphenhydramine hydrochloride.

The pyramidal and extrapyramidal systems are a complex series of upper motor neurons (UMN) that connect the cerebral cortex to distant body parts and influence muscular tone and control.

The pyramidal system controls skilled muscle movement.
The extrapyramidal system helps support the body against gravity (posture) and recruits spinal reflexes to initiate voluntary movement.

Where should a feline leukemia (FeLV) vaccine be injected?

A - Below stifle, lateral right hind
B - Above stifle, lateral right hind
C - Above stifle, lateral left hind
D - Below stifle, lateral left hind
E - Cervical interscapular region

Below stifle, lateral left hind. Feline leukemia virus (FeLV) and rabies vaccinations have been associated with sarcomas. You should always keep a record of where vaccinations were given.

Remember your L's and R's for feline vaccination:
For FeLV, vaccinate LOW and LATERAL on the LEFT hind.
For Rabies vaccinate low and lateral on the RIGHT hind.

Here is a direct quote from the AAFP Feline Vaccine Advisory Panel Report
"FeLV or FIV antigen (plus any other antigen except rabies) should be administered subcutaneously (SC) on the lateral side of the left hind limb below the stifle joint (vaccine-associated sarcomas arising in the proximal femoral area are difficult to completely excise; placement of vaccines in this area is strongly discouraged)."

What is the most common clinical sign exhibited by a horse with cystic calculi (bladder stones)?

A - Colic
B - Uremic breath and urethral ulcers
C - Straining to defecate
D - Inappetance
E - Hematuria after exercise

Bladder stones in horses are usually single, large spiculated stones composed of calcium carbonate. The most common clinical sign exhibited by horses with cystic calculi is hematuria after exercise. Hematuria is most evident toward the end of a voided urine stream. Other signs may include stranguria, pollakiuria and urinary incontinence.

In adult male geldings, urethral obstruction may also be associated with cystitis. If there is urethral blockage by smaller uroliths, stranguria, pollakiuria, incontinence, restlessness, colic and stretched posture may be more prominent.

A flock from a egg layer poultry operation is presented to investigate an outbreak of respiratory disease among a mixed-age population of adult chickens.

The owner reports a sudden onset of sneezing, nasal discharge and facial swelling among about 30% of the birds.

A typical sick chicken looks like the image below.

What is the clinical diagnosis?

A - Fowl Cholera
B - Infectious Bronchitis
C - Candidiasis
D - Infectious Laryngotracheitis
E - Infectious Coryza

This is Infectious Coryza. Think acute respiratory disease with nasal discharge, sneezing, and SWELLING UNDER THE EYES. Caused by Haemophilus paragallinarum (gallinarum), infected flocks are a constant threat to uninfected flocks; farms with multiple-age flocks can perpetuate disease. In the USA, "All-in/all-out" management has essentially eliminated infectious coryza from many commercial poultry farms. Follow this link to see original Merck image of Infectious Coryza.

Infectious Laryngotracheitis (ILT) look for gasping, coughing, blood stained beaks, blood occluding trachea on necropsy. A highly contagious herpesvirus infection, severe forms of ILT, can have 50% mortality. In most states ILT is REPORTABLE. Follow this link to see an image of ILT.

Infectious Bronchitis is characterized by respiratory signs, decreased egg production and poor egg quality. Classically may see "wrinkled eggs" with inf Bronchitis.

Pasteurella multocida causes Fowl Cholera. Think sudden onset septicemia. Signs vary greatly. In acute fowl cholera, dead birds are first indication of disease. May see fever, depression, anorexia, oral mucoid discharge, ruffled feathers, diarrhea, increased respiratory rate. Follow this link to see an image of Fowl Cholera.

Another name for Candidiasis is thrush. Think Candida albicans, thickened mucosa, whitish, raised pseudomembranes in crop, mouth and esophagus. Follow this link to see an image of Candidiasis.

A flock from a local broiler poultry farm is presented. Half of the flock has died in the last 10 days. Examination of the flock shows chickens that are gasping and coughing, extending their necks to inhale. Some have blood-stained beaks. There are no obvious neurologic signs.

Necropsy finds hemorrhage in the airways, as shown below.

The most likely presumptive diagnosis is?

A - Marek's disease
B - Infectious Laryngotracheitis
C - Infectious coryza
D - Viscerotropic Velogenic Newcastle disease
E - Fowl pox, diptheritic form

Blood in the trachea and this Hx suggest Infectious Laryngotracheitis (ILT). A highly contagious herpesvirus infection, ILT is characterized by RESPIRATORY signs (rales, severe dyspnea, coughing). In severe forms, mortality can reach 50%, typically due to occlusion of the trachea by blood, mucus or caseous exudates. In most states ILT is REPORTABLE.

Infectious coryza is a milder respiratory disease, with swelling around the eyes and head, sneezing, nasal discharge.

Newcastle disease is characterized primarily by respiratory signs. Severe forms include depression, neurologic signs or diarrhea. Look for GI hemorrhage with most severe form, Viscerotropic Velogenic Newcastle disease (VVND), which is REPORTABLE.

With Fowlpox, only a few birds typically affected with scablike lesions around head. Click here to see Fowlpox.

See only depression before death with Marek's disease . Some birds may have characteristic unilateral paresis (one leg forward, one leg back). On necropsy, see lymphoid tumors in organs and enlarged nerves.

In September, two Quarter Horse mares horses are presented that are pastured in a group of 5 in Oklahoma. The horses eat pasture grass supplemented by alfalfa hay and a small amount of grain.

One mare was found peracutely dead this morning. The other is depressed, anorexic and colicy.

Physical exam reveals dark, congested mucous membranes with small ulcer-like erosions. The mare makes frequent attempts to urinate, yielding red urine (hematuria) with a urine specific gravity (USG) of 1.006. She makes repeated attempts to drink small amounts of water and keeps her muzzle submerged in the water trough.

T=102.7 F (39.3 C)..[N=99-101.3 F]
HR=40 bpm............[N=28-40]
RR=20 brpm...........[N=10-14]

Necropsy of the other mare shows that the stomach and bladder linings are irritated and hemorrhagic.

What is the diagnosis?

A - Sorghum cystitis
B - Clostridium perfringens type A
C - Arsenic toxicity
D - Cantharidin toxicity
E - Enzootic hematuria

This is Cantharidin toxicity caused by blister beetles (Epicauta spp) which swarm in alfalfa hay during harvest.

Cantharidin is a potent irritant: see colic, renal disease, hematuria, peracute death. Follow this link to see a Merck image of Hemorrhagic gastritis. Follow this link to see a Merck image of Hemorrhagic cystitis.

Enzootic hematuria is a cow disease thought to be caused by Bracken fern toxicity. In horses, see thiaminase-related STAGGERS with bracken fern and with Horsetail (Equisetum spp) on U.S. West Coast.

Sorghum cystitis/ataxia is characterized by cystitis, urinary incontinence ("dribbling" ), posterior incoordination.

A 3-year old Quarter horse/Appaloosa cross mare is presented on emergency because she collapsed in the last 30 minutes.

The mare is recumbent and weak, with respiratory stridor, muscle fasiculations, sweating, prolapse of the third eyelid and her lips pulled back spasmodically, like a grin.

T=100.2 F (37.9 C)..[N=99-101.3 F]
HR=24 bpm.............[N=28-40]
RR=16 brpm............[N=10-14]

The horse is hydrated and has had no recent history of colic. During the examination, she improves markedly and within 60 minutes stands and appears almost normal again with no treatment.

What is the clinical diagnosis?

A - Hyperkalemic periodic paralysis (HyPP)
B - Equine degenerative myelopathy (EDM)
C - Epilepsy
D - Grass staggers
E - Myasthenia gravis

This is likely to be Hyperkalemic periodic paralysis (HyPP), an autosomal dominant trait found in ~ 4% of Quarter horses.

Heterozygotes often have periodic episodes 15-90 min: prolapse 3rd eyelid, muscle fasiculations, collapse. 25% cases traced back to one stallion named "Impressive".

Onset of signs unpredictable, and many triggers: diets high in POTASSIUM (>1.1%, ie: alfalfa hay, molasses, electrolyte supplements, kelp-based supplements). Fasting, anesthesia, heavy sedation, trailer rides, and stress can precipitate clinical signs.

Grass staggers think "goose-stepping" (overstepping) from ergot on grass. EDM think ataxia in foals 6-8 mos. Epilepsy poorly documented in horses. Myasth. Gravis basically a dog disease.

A 7 year-old intact female poodle is presented. The owner has noted a lot of drinking and some urinary "accidents" in the house in the last week and that the dog "hasn't seemed herself" either.

Yesterday she vomited twice. On physical exam the dog appears depressed and listless, has dark injected mucous membranes and a distended tender abdomen.

T=104 F (40 C)..[N=99.5-102.5 F]
HR=100 bpm.....[N=110-120]
RR=30 brpm......[N=15-34]

What diagnosis is of most immediate concern?

A - Pregnancy
B - Diabetes mellitus
C - Pyometra
D - Hepato-splenic tumor
E - Intestinal foreign body

The preferred answer is Canine pyometra.

Pyometra is a life-threatening emergency which typically requires immediate surgery (ovariohysterectomy) if the cervix is closed and there is no obvious discharge. Open cervix pyometras are likely to present with a purulent discharge, simplifying Dx, but surgical ovariohysterectomy is still STRONGLY recommended.

Pyometra should always be near the top of your DDX when presented with an older intact female dog or cat with a fever and distended abdomen.

Follow these links to see a pyometra radiograph in a Norwegian Elkhound and to see a pyometra ultrasound in a cat.

An emaciated cow is presented. She appears weak and anorexic, with enlarged superficial cervical lymph nodes.

She is somewhat dyspneic and has an intermittent hacking cough. Her manure looks normal.

T=102.9 F (39.5C)..[N=101.5-103.5 F]
HR=60 bpm............[N=55-80]
RR=30 brpm...........[N=10-30]

The cow dies the next day. On necropsy, the following lesion in the lungs is revealed.

What is the diagnosis?

A - Bovine tuberculosis
B - Actinobacillosis
C - Contagious bovine pleuropneumonia
D - Johne's disease
E - Bovine lymphoma

These are the classic granulomas of Bovine tuberculosis most commonly caused by Mycobacterium bovis or Mycobacterium tuberculosis in cattle. It is REPORTABLE. May also see granulomas on chest wall. Look for cows with chronic debilitation, emaciation, but WITHOUT the telltale watery diarrhea of Johne's disease.

Actinobacillosis causes Wooden tongue in cows. See granulomatous nodules in the tongue or may see submandibular swellings. Typically a disease of head, neck, limbs. Occasionally in lungs, pleura, udder, and subcutaneous tissue.

An 8-month old male German Shorthaired Pointer is presented with a history of intermittent hindlimb lameness which is exacerbated by exercise during hunting.

On physical exam the dog is painful on manipulation of the right stifle. Click here to see a radiograph of affected area.

What advice should the owner be given?

A - Need to test dog and owner for blastomycosis
B - Joint imbrication may prevent imminent cruciate ligament rupture
C - Good prognosis for return to function by 18 months of age
D - Need arthroscopy to confirm the diagnosis
E - Don't breed this dog

Discourage breeding of dogs with osteochondrosis (OC, or OCD).

Common sites for OC are the shoulder (caudocentral humeral head), elbow (medial aspect of humeral condyle), stifle (femoral condyle, usually lateral), hock (ridge of the talus, usually medial).

OC typically presents as a lameness in a young (4-10 mo), male (3x more likely than female), fast-growing, large breed dog; bilateral in 51%.

Prognosis for return to function is good to excellent with shoulder OC. More likely to see degenerative joint disease in elbow, stifle, hock OC.

A petting zoo is experiencing a high mortality outbreak among young chickens, guinea fowl, pheasants and turkeys.

Affected birds huddle near heat sources. They are off feed and weak, with whitish feces pasted around their vents (diarrhea).

On necropsy, lesions include unabsorbed yolk sacs and gray nodules in the liver, spleen, lungs, heart, gizzard, and intestine. There are firm, cheesy cecal cores.

This presentation is highly suggestive of which diagnosis?

A - Campylobacter jejuni
B - Coronaviral enteritis
C - Salmonella pullorum
D - Histomoniasis
E - Avian spirochetosis

This is the clinical picture of Salmonella pullorum, which usually causes very high mortality (potentially approaching 100%) in young birds.

Pullorum disease was once common in North America but has been eliminated from most commercial chicken stock. The disease may occur in other avian species (eg, guinea fowl, quail, pheasants, sparrows, parrots, canaries, and bullfinches).

A 4 year-old quarterhorse in California is presented with fever, lethargy, ataxia, icterus, petechiation, and limb edema.

A complete blood count shows characteristic neutrophil inclusion bodies suggesting equine granulocytic ehrlichiosis.
Click here to see inclusion bodies

Which one of the following choices is the most appropriate treatment?

A - Oxytetracycline
B - Euthanize. There is no effective treatment
C - Streptomycin
D - Penicillin
E - Chloramphenicol

Oxytetracycline is an extremely effective treatment for Equine granulocytic ehrlichiosis (Anaplasma phagocytophilum), most commonly seen in California in the United States. Dexamethsone may help horses with severe ataxia and edema (20 mg, sid for 2-3 days).

Penicillin, chloramphenicol, and streptomycin are not effective.

What is the most common cause for the problem seen in this turtle?

A - Hypovitaminosis B (thiamine)
B - Septicemic cutaneous ulcerative disease (SCUD)
C - Pasteurella multocida
D - Nutritional secondary hyperparathyroidism
E - Vitamin A deficiency

This is an aural abscess, secondary to vitamin A deficiency.

Captive terrestrial box turtles are most at risk, usually due to diets containing little vitamin A.

Other presentations of hypovitaminosis A include froth from nose (a sign of respiratory disease) and renal disease.

An 8-year old dog is presented with a 2-week history of occasional cough and moderate exercise intolerance.

On physical exam there are increased lung sounds. Thoracic radiographs show right ventricular enlargement.

Lab testing shows that the dog is heartworm antigen-positive, anemic and has proteinuria on urinalysis.

A - Cannot say without more information
B - Class II
C - Class IV
D - Class I
E - Class III

This is the clinical picture of class II heartworm disease (ie: moderate disease). In a nutshell, Class I is mild and class III is severe. Class IV is an acute shock-like syndrome (caval syndrome).

Canine heartworm disease can be classified with 4 parameters--physical exam, thoracic radiograph, packed cell volume (PCV) and urinalysis.

Class I heartworm disease is an asymptomatic-to-mild case with no radiographic signs and no lab abnormalities.

Class II heartworm disease is moderate, with occasional coughing and mild-to-moderate exercise intolerance. On physical exam there may be slight loss of body condition and increased lung sounds. Mild-to-moderate radiographic changes, like right ventricular enlargement are present. Lab results may show anemia and proteinuria.

Class III heartworm disease is severe. Variably characterized by weight loss, exercise intolerance and tachypnea at rest. Look for severe or persistent coughing, dyspnea, hemoptysis, fainting and ascites. Severely abnormal radiographs may show right ventricular hypertrophy, enlargement of the main pulmonary artery, and diffuse pulmonary densities. Labwork will indicate marked anemia, thrombocytopenia, and proteinuria.

Class IV heartworm disease (also called post-caval or caval syndrome) is an acute, shock-like presentation caused by retrograde worm migration from the pulmonary artery through the right ventricle, right AV valve and into the vena cava. Caval syndrome is characterized by acute collapse, hemoglobinuria, and respiratory distress. Usually fatal if surgery is not immediately instituted to physically remove worms.

After a stressful period of cold winter weather in northern Colorado, a petting zoo reports that one adult mule deer out of a herd of eight is sick.

On physical exam, the animal has a fever, increased respiratory rate and pulmonary rales, suggesting aspiration pneumonia.

Which one of the following choices is the most appropriate next step to take?

A - Report case to state health department
B - Perform an intradermal tuberculin test
C - Treat herd with high-dose penicillin
D - Treat sick animal with high-dose penicillin
E - Cull sick animal, vaccinate herd against histophilosis

Suspect chronic wasting disease (CWD) in any adult cervid with aspiration pneumonia. Reportable in most states and provinces, but especially in important in Colorado. CWD was first identified in northern Colorado in 1967 and remains more highly endemic there than anywhere else in the U.S.

Click here to see a USDA map of CWD distribution in wild cervids the US (scroll down to page 3).

Although weight loss is progressive throughout disease, remember that CWD may be present in deer and elk that are not thin or emaciated. Some animals may die of CWD without gross lesions. Death or clinical illness in CWD-affected animals can be precipitated by stressors like cold weather or restraint.

When present, the most common gross lesions due to CWD are poor body condition, watery rumen contents, and dilute urine.

A commercial turkey operation experiences an outbreak of disease in 40% of its 12-16 week old birds. Typically affected birds show only depression, then death.

Some animals appear weak, recumbent with one leg forward and one leg back.

On necropsy, diffuse or nodular lymphoid tumors are visible in various organs, particularly the liver, and spleen. Two affected birds have distorted pupils.

What is the diagnosis?

A - Viral hepatitis of turkeys
B - Histomoniasis
C - Infectious bursal disease
D - Newcastle disease
E - Marek's disease

Yes, turkeys can get Marek's disease.

A transient paralysis with one leg forward, one leg back is a classic sign of Marek's-just don't expect to see it in all birds. Typically affected birds show only depression, then death.

You may see diffuse or nodular lymphoid tumors are visible in various organs, particularly the liver, spleen and other organs. Lymphoid infiltrates can cause distortion of the pupil and enlargement of feather follicles ("skin leukosis"=condemnation of carcass).

A 5 year old quarterhorse is presented with a depigmented hyperkeratotic plaques localized to the concave aspect of both ears.

[Disease of the pinna]

What message should be communicated to the owner?

A - Need to check the pasture for photosensitizing plants
B - Lesions usually persist for life
C - Do not breed this horse
D - Surgical removal is curative
E - Typically secondary to underlying immunosuppression

Equine aural plaques (papillary acanthoma, ear papilloma) typically persist for life.

Equine aural plaques are caused by a papillomavirus and thought to be transmitted through mechanical transmission by biting Black flies (Simulium spp.)

There is no specific treatment. Prevention includes application of fly repellent and stabling the horse during the Black fly's feeding times (dusk and dawn).

Which one of the following ectoparasites normally spends its entire life cycle on the chicken, causing feather damage, anemia and irritation?

A - Red chicken mite
B - Trombicula alfreddugesi
C - Dermanyssus gallinae
D - Northern fowl mite
E - Neocnemidocoptes gallinae

The Northern fowl mite (Ornithonyssus sylviarum) is the only poultry mite that normally spends its entire life cycle on the host. O. sylviarum is the most important parasite of caged layers and breeding chickens in the U.S..

MOST chicken mites are nocturnal feeders that are only on the birds at night. They hide during the day away from the chicken, under manure and in crevices of the chicken house, where they lay eggs.

A 4-year old German shorthair hunting dog from the mid-Atlantic United States is presented with a right forelimb lameness of 2 weeks duration. A plain radiograph below is shown below.

What is the next appropriate diagnostic step?

A - Fine needle aspirate from affected joint
B - Histoplasmosis titer
C - Bone biopsy and bacterial culture
D - Thoracic radiographs
E - Contrast fistulogram

Bone biopsy is required for definitive diagnosis of lytic bone lesion to differentiate between infection and neoplasia. Culture is indicated as well.

The joint-crossing lytic damage seen between p2 and p3 is due to osteomyelitis (infection). Among bacterial causes, Staphylococcus spp are most common. 40%-50% of cases are polymicrobial with both anaerobes and aerobes present, and 70% of all cases test positive for some kind of anaerobe.

Osteosarcoma, an aggressive bone tumor, usually does not cross joints, but it still takes biopsy and culture to be definitive.

The calf in the image below is presented with fever, depression, visual deficits and neck rigidity due to colisepticemic meningitis

What management action will help prevent this problem in the future?

A - Ensure adequate colostrum uptake
B - Vaccinate dam with bacterin after calving
C - Cull mothers of affected calves
D - Serologic testing for phospholipase D exotoxin
E - Prophylactic sulfonamide antibiotics

Ensure adequate colostrum uptake. The calf is head-pressing, one sign of meningitis due to central nervous system disease.

Colisepticemic meningitis in calves is usually secondary to failure of passive transfer. The best prevention of colibacillosis is threefold:

1. Prevent failure of passive transfer (FPT) by ensuring colostrum uptake.
2. Better sanitation.
3. Vaccinate dam at 6 and 3 weeks before calving with bacterin (K99 + E. coli). Because here are many variants of E.coli, vaccinating the dam to protect the calf is difficult. The cornerstone of prevention is to make sure the calf gets that colostrum.

In adult cattle, thrombotic meningoencephalitis may be caused by Histophilus somni.

In pigs, see meningitis due to Haemophilus parasuis (Glasser's disease). Listeriosis causes a sporadic meningoencephalitis in cows and small ruminants

A valuable female show dog is approaching estrus and the owner wants her bred by artificial insemination to one of the most successful and expensive stud dogs in the country.

What testing method is most accurate to insure optimum timing for breeding the bitch?

A - Progesterone assays
B - LH monitoring
C - Vaginoscopy
D - Estrogen levels
E - Vaginal cytology

Daily testing for the LH surge is the most accurate method of ovulation timing. The day of the LH surge becomes "day 0" and you plan breedings from there, typically at days 2, 4 and 6. You might choose LH monitoring for frozen or chilled semen breedings, infertility cases or breedings with valuable, or subfertile studs.

Progesterone assays, vaginal cytology and vaginoscopy are all useful adjuncts to breeding management. Progesterone starts to increase at about the same time as the LH surge- although progestrone levels are not as accurate as measuring the actual LH surge, the tests may be more convenient and available than LH tests.

Estrogen measurement is of little value for ovulation timing because peak levels vary from dog to dog and do not necessarily correlate with the fertile period. Increased estrogen speeds up the turnover of vaginal epithelial cells, which causes progressive cornification seen on vaginal cytology.

A dog presents with a history of eating a shiny new United States penny that was hidden in a piece of birthday cake.

What problem may result?

A - Nickel toxicity
B - Molybdenum poisoning
C - Lead poisoning
D - Iron poisoning
E - Zinc toxicity

Think of zinc toxicosis associated with ingestion of U.S. Lincoln pennies. All pennies minted since 1984 (and a few in 1983), are 97.5% zinc by weight.

Other sources of zinc include batteries, car parts, paint, zinc-oxide sunscreen creams, zippers, board-game pieces, screws and nuts on pet carriers, and the coating on galvanized metals like plumbing pipes and some cookware.

Copper toxicity is typically associated with copper containing drenches for sheep, or improperly formulated rations.

Molybdenum poisoning is an uncommon problem of cattle.

Iron poisoning is a sporadic problem of newborn piglets overdosed by iron injection.

After diagnosis of appendicular osteosarcoma in a dog, the leg is amputated and chemotherapy is initiated. At follow-up monitoring exam 3 months later, thoracic radiographs are clear.

What finding would suggest a guarded prognosis?

A - Elevated albumin, depressed globulin
B - Polycythemia
C - Microcytosis
D - Elevated alkaline phosphatase
E - Depressed calcium-phosphorus ratio

Elevated alkaline phosphatase is associated with a poor prognosis prior to surgery for osteosarcoma. If alkaline phosphatase stays elevated postoperatively, the prognosis is even more guarded. The median survival of dogs with appendicular osteosarcoma is only 4-5 months after amputation alone, and 10-12 months with amputation plus chemotherapy.

90-95% of animals with osteosarcoma ultimately develop visible metastatic disease. The foundation of monitoring for osteosarcoma after amputation and adjunct chemotherapy is 3-view thoracic radiographs every 2-3 months.

Think of microcytotic anemia with iron deficiency in young rapidly-growing animals like piglets and puppies and with portosystemic shunts. Think of polycythemia (high RBCS) most commonly secondary to dehydration.

During a fecal examination of a 2 month old piglet this organism is seen.


What is the diagnosis?

A - Ancylostoma
B - Ascaris
C - Trichuris
D - Eimeria
E - Strongyloides

Ascarids in pigs (roundworms) resemble ascarids in dogs and cats and also ascarids in horses. Ascarid eggs look a little like a fried egg with a big yolk. Click here to compare images:
Equine ascarid egg
Canine ascarid egg
Porcine ascarid egg

Here are images of several other key parasite eggs.
Trichuris (whipworm)
Ancylostoma, Uncinaria (hookworm)
Tapeworm (resemble hookworm eggs, but larger)
Strongyloides have small, thin-shelled (20-35 × 40-55 micrometers) embryonated eggs (larval worm visible inside). Strongyloides ova must be differentiated the embryonated ova of lungworms (Pigs, Metastrongylus, 33-42 × 51-63 micrometers).

These are the key lungworms in different animals:
Dictyocaulus in cattle, deer, donkeys and horses
Protostrongylus and Muellerius in sheep and goats
Metastrongylus in pigs
Oslerus (Filaroides) in dogs
Aelurostrongylus and Capillaria in cats.

A newborn foal with hypoxic ischemic encephalopathy and a poor suckle response is being treated supportively with mare's milk via nasogastric tube, IV fluids with 5% dextrose and broad spectrum antibiotics.

What other treatment is often critical to caring for foals like this?

A - Mannitol
B - Famotidine
C - Diazepam
D - Isoxuprine HCL
E - Metoclopramide

Seizure control with diazepam (0.11-0.44 mg/kg) is critical for foals with hypoxic ischemic encephalopathy(HIE). Repeat dosage as needed. If long-term control is required, try phenobarbital (2-10 mg/kg, IV, bid-tid).

Dimethyl sulfoxide (DMSO 1 g/kg in a 10% solution, IV) can be used to help decrease cerebral edema.

Mannitol (1 g/kg as a 20% solution, IV) has been proposed to decrease cerebral edema, but must be used with caution: HIE foals often have subdural hemorrhage.

In addition to supportive care (warmth, nutrition, fluids, colostrum/plasma), remember the three "S's" of HIE problem management--

What are ongoing losses in fluid therapy?

A - Percent dehydration multiplied by body weight
B - Vomit and diarrhea
C - The tears I shed when I can't make sense of fluid calculations
D - Fluids given minus extracellular volume estimate
E - Urine output

Ongoing losses are typically vomiting, diarrhea or other losses into a third compartment (pleura, abdomen etc). These are sometimes called "contemporary" losses. A classic example of a disease with significant ongoing losses is a puppy with parvovirus who has both diarrhea and vomiting.

Sensible losses are easily measured, like the fluids the animal loses by urination.

Insensible losses are the fluids an animal loses that are hard to measure, through breathing and via the skin. In humans and animals that sweat (like horses) sweating is part of insensible losses.

Remember that all three types of loss must be accounted for (or at least estimated) when calculating fluids needed to rehydrate a dehydrated animal.

A cat is presented with bilateral conjunctivitis and rhinitis. A conjunctival scrape looks like the following image.

What is the diagnosis?

A - Ureaplasma noeti
B - Mycoplasma felis
C - Chlamydophila spp
D - Feline reovirus
E - Feline viral rhinotracheitis

An inclusion body inside of a cell in eye discharge suggests Chlamydophila spp (ie: Chlamydophila felis). Follow this link to see the original Merck image of a chlamydial inclusion body.

Genetic testing led to taxonomic reclassification in 1999, but many sources still refer to Chlamydophila felis infection as "Chlamydophila psittaci" or Chlamydiosis.

Although C. felis is a potential zoonotic disease, there are only a few reports of mild conjunctivitis in people from infected cats.

This is IN CONTRAST to the zoonotic potential of pet birds infected with Chlamydophila psittaci, which can apparently infect people more readily than the mammalian version. Single best ref on Psittacosis (what it is called when people get Chlamydophila), is the 2009 AVMA Compendium of measures to control Chlamydophila.

A feeder pig operation has a problem with sudden onset of diarrhea followed by collapse and death in piglets 1-3 days old. On necropsy, the following lesions are evident.

What is the presumptive diagnosis?

A - Lawsonia intracellularis
B - Clostridium perfringens Type C
C - Hemorrhagic bowel syndrome
D - Enterotoxigenic Escherichia coli (ETEC)
E - Brachyspira (Serpulina) hyodysenteriae

These are the hemorrhagic intestines of Clostridium perfringens Type C. Affects piglets up to 3 weeks old with a severe hemorrhagic necrotizing diarrhea. High mortality.

Brachyspira (Serpulina) hyodysenteriae is a treponemal spirochete that causes Swine Dysentery. Think MUCOID hemorrhagic diarrhea (ie: large intestine) in pigs 6 to 20 weeks old. Diarrheic pigs become dehydrated, profoundly weak, and emaciated.

Lawsonia intracellularis causes Porcine proliferative enteritis, a common diarrheal disease in growing-finishing pigs and younger breeding pigs.

Clostridium difficile is an emerging diarrhea pathogen principally in neonatal swine- may also see dyspnea, abdominal distention, scrotal edema.

Enterotoxigenic Escherichia coli (ETEC) causes EDEMA disease in recently weaned piglets with peracute death or neurological signs: ataxia, paralysis, and recumbency, and head swelling.

A canine vaginal smear looks like the image below through a microscope.

At what stage of the estrous cycle is this dog?

A - Estrus
B - Proestrus
C - Anestrus
D - Cannot tell from this slide
E - Diestrus

Think CORN FLAKES with ESTRUS. Look for greater than 90% CORNIFIED superficial cells (angular, sharp edges like , tiny pyknotic nuclei or no nuclei) when you think canine estrus, and NO NEUTS. Follow this link to see the an estrus vaginal cytology image.

In contrast, DI-estrus vaginal smears will have more than 10% nucleated, round-edged parabasal and intermediate cells. Look for the reappearance of some neutrophils (variable numbers). Follow this link to see a DI-estrus vaginal cytology image.

Full cornification usually coincides with receptivity. Serum progesterone can predict the LH surge and help estimate ovulation.

RULE OF THUMB: Breed bitch as soon as she will allow a male to mate or as soon as you see greater than 90% cornified superficial epithelial cells in a vaginal smear. Typically breed every 2-4 days until bitch enters diestrus for maximum fertility success.

What is the primary clinical presentation in chickens infected with Campylobacter jejuni?

A - Hemorrhagic diathesis
B - Enterocolitis
C - Diptheritic tracheitis
D - Nothing
E - Depression, anorexia, lethargy

The preferred answer is "nothing". Campylobacter jejuni from contaminated chicken is one of the leading causes of enterocolitis IN HUMANS, but the chickens themselves are asymptomatic.

During a routine immunization visit for a 2 year-old neutered male Newfoundland dog, a systolic murmur is detected which is heard loudest on the left side of the chest between the 2nd and 5th intercostal (IC) space and at the thoracic inlet lateral to the trachea.

Which condition is highest on a differential diagnosis list?

A - Aortic stenosis
B - Mitral dysplasia
C - Patent ductus arteriosus (PDA)
D - Tricuspid dysplasia
E - Pulmonic stenosis

Aortic stenosis (also called sub-aortic stenosis [SAS]), is a systolic murmur which may be heard most loudly on the left chest between the 2nd and 5th intercostal (IC) space or at the thoracic inlet (lateral to trachea).

Inherited in Newfoundlands. Predilection in many BIG BREEDS- German Shepherd, Golden Retriever, Boxer, Rottweiler.

Mitral dysplasia and other mitral valve problems are heard further back on left at 5th-6th IC. More common in CATS.

With Pulmonic stenosis see RIGHT ventricular hypertrophy, because pulmonic valves blocks outflow from R ventricle (mostly dogs). Follow this link to see a Merck image of Rt. ventricular hypertrophy.

Tricuspid dysplasia is heard further back on RIGHT at 5th-6th IC. Uncommon.

Expect a continuous murmur with Patent ductus arteriosus (PDA). Vast majority detected at first vaccination visit.

Which one of the following choices is a major clinical complication of equine pituitary pars intermedia dysfunction?

A - Colic
B - Circling, Head-pressing
C - Dyshormonogenetic goiter
D - Laminitis
E - Diabetes insipidus

The major clinical complication of pituitary pars intermedia dysfunction (PPID, hyperadrenocorticism) is laminitis, affecting more than 50% of the horses with PPID.

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