Terms in this set (318)

B. Mosquito control

Correct: The condition described here is is the dry form of avian (fowl) pox. This is a relatively slow spreading disease that can be spread by contact or by mosquitoes that may harbor infective virus for greater than a month.
In the dry form of the disease, the main sign is raised, whitish wart-like lesions on unfeathered areas (head, legs, vent, etc.). The lesions heal in about 2 weeks. Unthriftiness, decreased egg production and retarded growth may be seen. Mortality is low with this form of the disease. The wet form mainly involves the oral cavity and upper respiratory tract. Lesions are diphtheritic and can ulcerate or erode mucous membranes. Marked respiratory involvement can lead to mortality
A diagnosis is usually based on flock history and presence of these lesions. This is a pox virus and there is no specific effective treatment but there is a vaccine. Disease control is best accomplished by preventive vaccine as sanitation alone will not prevent spread of disease. Several vaccines are available and a single application results in permanent immunity.

There are not many tick borne poultry diseases but they may include spirochaetosis and Pasteurella infection.
Raising the temperature 5 degrees may be part of the treatment for infectious bronchitis in chickens. Disinfecting pens +/- quarantine is done for quail bronchitis, aspergillosis, and ulcerative enteritis. Antibiotics in the drinking water are most effective for preventing secondary bacterial infections and for mycoplasma but not preventing spread of the virus.
A. Administer ivermectin twice annually, once in the early summer and again in the fall
Correct: This case describes the appearance of the horse bot fly, Gasterophilus spp. Gasterophilus is frequently asymptomatic but treatment is recommended because bots can cause gastritis and frequently are a source of annoyance and stress to horses. In addition, the larval instars can cause stomatitis, and colic.

The key to answering this question regarding optimal treatment and management is an understanding of the Gasterophilus life cycle. Gasterophilus undergoes complete metamorphosis, including three larval instars and only one generation is produced per year. The general cycle typically begins with the female ovipositing 150-1,000 eggs on a horse during the early summer months directly on single hairs of the horse's front legs (especially around the cannon bone area) as well as the abdomen, flanks, and shoulders. The eggs are approximately 1-2mm long and are pale to grayish yellow attached near the tip of the hair.

The eggs develop into first instar larvae within five days and they are stimulated to emerge by the horse licking or biting at the fully developed eggs. The larvae then crawl to the mouth or are ingested and subsequently bury themselves in the tongue or gingiva and remain for approximately 28 days. The larvae molt to the second stage and move into the stomach. The second and later third stage larvae typically attach to the lining of the stomach in the non-glandular portion near the junction of the esophageal and cardiac regions where they remain immobile for the following 9 to 12 months.

The third instar larvae are relatively large, between 1-2cm long with a rounded body, narrow, hooked mouthparts, and spines. The hooked mouthparts enable the larvae to securely attach to the lining of the stomach and intestinal tract. After the third instar larvae have matured, they detach from the gastrointestinal tract and pass from the horse's body in the feces. The larvae burrow into the soil or dried manure where they pupate and remain for the next one to two months. This stage of the life cycle occurs between late winter and early spring.

Based on this life cycle, the recommended management protocol is typically to treat with an avermectin to control adults and all larval stages by administering in the early summer, shortly after any eggs are seen and again in the fall at the end of the botfly season. Such a control program will substantially reduce fly numbers.
C. Exploratory laparotomy to remove the ovarian remnant

Correct: This is a classic description of ovarian remnant syndrome, which is when a cat goes into estrus after previously having an ovariohysterectomy (OVH).

This can occur anywhere from weeks to years after OVH and typically the clinical signs consistent with estrus are sufficient to conclude that the cat is in estrus and has ovarian tissue present. Additional diagnostic tests that are consistent with ovarian remnant syndrome include:

Serum estrogen >70 pmol/L indicate that the cat has estrogen production from the ovary. The problem with this test is that estrogen measurements may fluctuate and can be unreliable.

Serum progesterone >6 nmol/L after induced ovulation is sufficient to conclude that corpora lutea formed and released progesterone.

Testing for serum LH levels can also help confirm the diagnosis. In intact queens, LH is consistently maintained at basal levels due to negative feedback from ovarian estradiol secretion. After OVH, this control is lost and LH concentrations increase. LH <1 ng/mL is consistent with the presence of an ovary as it is in this case.

Surgery is the treatment of choice. Many practitioners prefer to do surgery during estrus or diestrus when the ovarian tissue is enlarged and easier to locate. Remnants may be bilateral so a complete exploratory laparatomy is necessary. Ovarian tissue is most commonly at the ovarian pedicle but can also be in the mesentery or elsewhere.

You should be aware that ovarian remnant syndrome is NOT associated with new graduates or inexperienced surgeons (it is not likely the fault of the initial surgeon). It is suspected that accessory ovarian tissue separate from the ovary within the ovarian ligament or proper ligament of the ovary may become functional and cause this condition in most cases
A. Lipoma

Correct: The cells depicted are well-differentiated adipocytes. These cells are large, appear in aggregates or sometimes singly, and contain fat that stains negatively with Wright's, such that the cytoplasm appears clear. The cells possess a small, round or ovoid, pyknotic nucleus that may be compressed and located in the periphery of the cell. This benign tumor is a lipoma, which is common in dogs. If the mass hinders the animal, it may be removed surgically. Infiltrative lipomas, and their malignant counterpart, liposarcomas, are less common.

When sampling for cytology, frequently the first indication that a lipoma has been aspirated is the clear, oily appearance of the material ejected from the aspiration needle onto the slide. Care must be taken while staining to ensure that the material does not wash off the slide, as fat does not adhere readily to the glass surface.

Note: Gentle heat fixing of greasy material to a slide may be of benefit in keeping adipose cells adherent to slides during staining. This can be accomplished by holding a slide over a Bunsen burner or lighter or gentle heating on a heating tray/bar for a few seconds so that the side opposite to that containing the cellular material is slowly warmed. The slide must be left to cool completely before staining. Slides coated with poly-l-lysine, which are used for Papanicolaou staining and/or increased adherence of tissue sections to slides, are also helpful in promoting cellular adherence and eliminating loss of cells during staining.

Sometimes, local fat will be aspirated and cannot be reliably differentiated from the adipose cells of a lipoma. If there is any doubt as to the presence of a discrete mass, surgical removal with histological evaluation is recommended.
B. Acetylcysteine and S-adenosylmethionine

Correct: Acetaminophen toxicity in cats usually occurs when owners administer the drug, unaware of its significant potential toxicity in cats. In this case, the cat's clinical signs are most consistent with acetaminophen toxicity based on the Heinz body anemia that is present. Cats can die from oxidative damage and methemoglobinemia within 1-2 days of ingestion. It may also be associated with hepatotoxicity in cats, although this is seen more frequently in dogs.

Recall that cats are particularly sensitive to acetaminophen because they have decreased glucuronyl transferase activity which conjugates acetaminophen to glucuronic acid for excretion. As a result, 50-60 mg (a single tablet) may be fatal for a 4-5 kg cat.

Treatment should consist of toxin removal if possible by inducing emesis in some cases. As the cat in this case is already vomiting, this may not be necessary. Activated charcoal is controversial and should only be given if ingestion occurred within hours and should be administered very carefully in cats due to the risk of aspiration.

The specific antidote is acetylcysteine which binds to some of the reactive metabolites of acetaminophen and increases the availability and synthesis of glutathione. Other treatments may include S-Adenosylmethionine (SAMe) which has hepatoprotective and antioxidant properties. Cimetidine can be given to inhibit the p450 oxidase in the liver and limit formation of toxic metabolites. Ascorbic acid can also be used as an adjunct treatment to bind toxic metabolites. In cats with signs of hypoxemia from severe hemolytic anemia (PCV <20%), a transfusion and further supportive care may be warranted.
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