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Pathology of the urinary system

Terms in this set (123)

What are the requirements for normal renal function?
Functional renal tissue
Adequate blood perfusion
Elimination of urine
What species have a unipyramidal kidney?
Cats, dogs, small ruminants, and horses
What species have a multi-pyramidal kidney?
Swine and bovids
What is unique about the cortex of a cat's kidney?
It is yellow due to the large lipid content of the tubular epithelial cells
What are mesangial cells?
Phagocytic cells in the kidney, synthesize collagen and the mesangial matrix
What is the juxtaglomerular apparatus?
The conjunction of the arterioles, glomerulus, and distal tubule. Controls GFR.
What is the structural/functional unit o the kidney?
Nephrons
How should the average kidney appear?
2.5-3 vertebrae in length
Easily removed fibrous capsule (exc horses)
Smooth capsular surface
Understand 'normal' varies in species
Kidneys receive ___% of the cardiac output of blood
25
How does a kidney that has undergone hyperemia/congestion appear?
Dark red and oozes blood on the cute surface
What are the three processes that can lead to a hyperemic/congested kidney?
Active (hyperemia) - acute inflammation
Passive (congestion) - heart failure, venous obstruction
Hypostatic congestion - unilateral agonal change
What can cause multifocal cortical hemorrhages?
Bacteremias/viremia secondary to vasculitis/necrosis/toxins
What are potential causes of occlusions that lead to renal infarcts?
Primary thrombi or embolic showers
What is the progression of a renal infarct?
Acute - swollen and red
Subacute - pale with zone of red
Chronic - pale and shrunken
Vasculitis in the kidney can lead to various lesions in various species, what are the ones we learned in class?
Porcine circovirus - 2
MCF
Canine herpesvirus 1
Most primary glomerular disease is ________-mediated and ___________ in nature
immune mediated and inflammatory
What is a CS that is highly suggestive of glomerular disease?
Heavy proteinuria in the absence of sediment abnormalities
Define glomerulitis
inflammation restricted to glomeruli, occurs in acute septicemias
Define glomerulonephritis
Inflammation of the glomerulus and nephron, implies secondary changes accompanying the primary glomerular disease
Define glomerular amyloidosis
Deposition of amyloid fibrils in the glomerular basement membrane
What species does glomerulonephritis occur most commonly in?
Dogs
What is exudative glomerulitis? Cause?
Acute exudation of neutrophils
Bacterial septicemia
What typically causes glomerulonephritis in dogs?
Deposition of circulating immune complexes (type 3 hs)
How does chronic glomerulonephritis appear grossly?
Capsular surface is pitted, due to fibrosis, and on the cut surface the cortex may be thinned and granular with pale gray dots (glomeruli)
What causes amyloid?
excess production of biproducts from chronic antigenic stimulation
What does amyloid deposition cause in the kidneys?
Pressure atrophy
Where is the location of amyloid in most dogs?
Glomerular
What are the clinical pathology signs associated with amyloidosis?
Marked proteinuria and hypoalbuminemia
What are the gross findings associated with amyloidosis?
Kidneys are enlarged, pale, and have a smooth to granular capsular surface. Can appear pale/waxy/fine on the cut surface.
What are the consequences of glomerular disease?
Protein losing nephropathy
Procoagulant state
Renal failure
What can be a sequelae of a protein losing nephropathy?
Becoming hypoproteinemic (edema)
What can be a sequelae of the procoagulant state seen in glomerular disease?
v AT III
Thombi
What is Acute Kidney Injury (AKI)?
Abrupt ^ in serum CREA and BUN
Azotemia
What is Acute Tubular Injury (ATI)?
Most important cause of acute renal failure, life threatening.
Nephrotoxic or ischemic causes
What are potential causes of nephrotoxic ATI?
Drugs (aminoglycosides, cephalosporins, tetracyclines, sulfonamides, amphotericin b, and antineoplastic agents)
Ethylene glycol
Melamine/cyanuric acid
Plants (lilies, oak leaves/acorns, raisins/grapes)
Heavy metals
Mycotoxins
Vit D intoxication
What is the gross appearance of a kidney that has undergone a nephrotoxic ATI?
Swollen and pale and the cortex may bulge from the cut surface and appear moist. The medulla is pale/congested
What is the most important cause of tubular necrosis in small animals?
Ethylene glycol poisoning (antifreeze)
How to dx ethylene glycol toxicosis at necropsy?
Scrape the cut surface of the kidney and smear onto a slide, calcium oxalate precipitates will glow under polarized light.
How will melamine/cyanuric acid poisoning appear grossly?
Gold-brown circular crystals located in the distal tubules
What can vit D toxicity cause systemically?
Renal, tendon, ligament, and cardiovascular MINERALIZATION
What are causes of ischemic tubular necrosis?
Reduced renal perfusion
Hypoperfusion complicated by hemoglobinuria
Hypoperfusion complicated by myoglobinuria
What can cause red urine?
Hemoglobinuria
Myoglobinuria
Hematuria
What are the potential outcomes of renal tubular necrosis?
Regeneration if the basement membrane is intact, fibrosis if not.
What is the gross appearance of a hemoglobinuric ischemic kidney?
Dark red
What causes papillary or renal medullary necrosis?
Ischemia caused by vasoconstriction or compression of vessels lasting longer than two hours
What are causes of ischemia leading to papillary/renal medullary necrosis?
Excessive NSAID use
Urinary obstruction
Pyelonephritis
Amyloidosis
What can be seen with ultrasound that is indicative of NSAID toxicity in equine adults/foals?
Renal medullary rim sign (hyper-echoic band parallel to the corticomedullary junction)
What are sequalae to papillary/renal medullary necrosis?
Obstruction by sloughed material
Calculus formation (—>stones)
Disruption of the external surface of the papilla (allows for bacteria to enter ascending)
Normal cat kidney
A kidney that has undergone serous atrophy of fat
Top kidney has undergone hypostatic congestion
Lesions seen in the kidneys of swine with hog cholera/African swine fever, Erysipelothrix, salmonella, or circovirus
Lesion seen in the kidney of dogs with canine herpesvirus
Lesions seen in the kidneys of patients with vasculitis
Hyaline casts caused by glomerulonephritis
Nightmare fuel (Dioctophyma renale - giant kidney worm)
Acute renal infarct of a dog
Comparison of a normal cat kidney and one with amyloidosis
Toxic vs ischemic acute tubular necrosis kidneys
Oxalate crystals in an urine sediment that is representative of ethylene glycol toxicosis
What is a potential cause of perirenal edema in cats?
Lily toxicosis
What can cause hydrothorax, perirenal edema, and pale kidneys with petechiae?
Oak toxicosis
Kidneys of a patient with aminoglycoside toxicosis (neomycin)
Kidneys of patient with pigmented (hemoglobin) ischemic tubular necrosis
Lesions seen with chronic copper toxicosis
Lesion seen with red maple toxicosis in horses
Lesions seen with papillary necrosis
How does a kidney with acute/subacute primary tubulointerstitial nephritis appear?
W/ multifocal white foci throughout the renal cortex and medulla
What type of viral agents cause tubulointerstitial or interstitial nephritis?
FIP
Canine herpes
Equine viral arteritis
What type of bacterial agents cause tubulointerstitial or interstitial nephritis?
Lepto
Corynebacterium
E.coli (cattle)
What type of fungal agents cause tubulointerstitial or interstitial nephritis?
Aspergillus (GSD)
Histoplasma
Algae
What type of parasites cause tubulointerstitial or interstitial nephritis?
Toxocara canis
Toxoplasma gondii
Halicephalobus gingivalis
Encephalitozoon cuniculi
What type of plants can cause tubulointerstitial or interstitial nephritis?
Hairy vetch in cattle
When renal functional capacity is abruptly impaired by __% or more, acute renal failure can ensue
75
What causes death in animals with acute renal failure?
Cardiotoxicity of elevated serum potassium, metabolic acidosis and/or pulmonary edema
What are clinical signs that can be seen in a patient with acute renal failure?
Oliguria/anuria
V/D
Ammonia breath
What are 'end stage kidneys'?
Small, pitted, and fibrotic.
Cannot differentiate cause.
What are general causes of pre-renal level renal failure?
Conditions that cause v blood flow or local obstruction to vascular supply
What are general causes of renal level renal failure?
Disease/lesions that interfere with renal function and waste products are retained in the blood
What are general causes of post-renal level renal failure?
Disease/lesions of the lower urinary tract that prevent excretion of urine
What causes uremia?
The accumulation of toxins in the blood and tissues due to renal failure
Why are uremic patients acidotic?
Bicarb is not being reclaimed from filtrate
Because renal failure can lead to hyperphosphatemia, what secondary disease can occur?
Secondary hyperparathyroidism, contributes to soft tissue mineralization
What is the main clinical manifestation of systemic hypertension?
Retinal detachment
Why is a horse's urine naturally cloudy?
Mucus and calcium carbonate crystals
What are two developmental abnormalities of the lower urinary tract?
Ectopic ureters and patent urachus
What is one of the most important causes of urinary problems in domestic animals?
Uroliths
What are factors that lead to calculi formation?
pH
Bacterial infection
^ dietary PO4
Dehydration
Breed
NSAIDs
What type of stones are commonly seen in the urine of dogs with portal-caval shunts?
Ammonium biurate crystals
What can predispose an animal to bacterial cystitis?
Urinary stasis
What is the most common cause of cystitis/pyelonephritis in pigs?
Actinobaculum suis
What is the most common cause of cystitis/pyelonephritis in cattle?
Corynebacterium renale
C. cystitidis
MCF
What is the most common cause of cystitis/pyelonephritis in dogs?
E.coli
Proteus sp
Klebsiela sp
Staph sp
What is the most common cause of pyelonephritis in dogs or pigs?
Dogs - dioctophyma renale
Pigs - Stephanurus dentatus
How does acute cystitis appear?
Hemorrhagic, fibrinopurulent, necrotizing, or ulcerative
What are the two forms of chronic cystitis?
Follicular - white lymphoid nodules with red rims
Polypoid - Inflamed connective tissue with ulceration or hyperplasia
What can cause sterile hemorrhagic cystitis in cats and dogs?
Cyclophosphamide admin
What is a toxic cause of hemorrhagic and ulcerative cystitis in horses?
Cantharidin toxicosis
What is a cause of emphysematous cystitis in dogs?
Diabetes mellitus, neuro disease, and adrenal disease
What causes neuro problems with the bladder in dogs?
IVDD
What causes urinary bladder atony in horses?
Accumulation of calcium carbonate sediment + Cauda equina neuritis
What species can have idiopathic cystitis?
CATS!
Horses
It's always these two isn't it?
What is the most common cause of a urinary bladder rupture?
Urethrolithiasis
What can cause rupture of a male foal's bladder?
If it is full during parturition and the urethra is occluded, pressure on the bladder can cause rupture along the dorsal surface
What can the presence of renal unilateral hypoplasia lead to?
Compensatory hyperplasia in the other kidney
What is juvenile onset chronic kidney disease?
Any non-inflammatory, degenerative, or developmental chronic kidney disease in animals <2
How can the kidneys of patients with juvenile onset chronic kidney disease appear?
Small and misshapen
What feline polycystic kidney disease (PKD1)?
Heritable disease seen in persian cats.
Swiss cheese appearance and leads to renal failure
Primary renal neoplasia are uncommon, what is the source of most neoplasia seen in the kidney?
Metastasis
What are the two most common primary neoplasias of the kidney?
Tubular epithelium carcinomas (older dogs) and embryonal nephromas (young pigs/chickens)
In the cat/cow what morph changes can you see with renal lymphoma in the kidney?
Single/multiple pale tan nodules
How to differentiate renal lymphoma from FIP lesions in the kidney of the cat
FIP lesions will follow the VESSELS
Tumors of the urinary bladder happen most commonly in what age group of animals? What are the CS?
Older
Dysuria, hematuria, or obstruction
What is the most common tumor of the urinary bladder? Where does it most commonly occur?
Urothelial carcinoma
Trigone area
What breed is predisposed to urothelial carcinoma?
Scottish terriers
How can we iatrogenically cause transplantation of urothelial carcinomas?
Through percutaneous fine needle aspirates
Ulcerated urothelial carcinoma
What does ectopic ureters predispose an animal to?
Urocystitis, pyelitis, and pyelonephritis
Examples of acute and chronic pyelonephritis
Examples of bacterial pyelonephritis
Examples of emphysematous cystitis (Diabetes, uti, addisons)
Example of hydronephrosis
Renal gout can occur more in what species? Why?
Birds/reptiles, because they excrete uric acid rather than urea
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