Final Exam - Food Animal Renal Disease Flashcards
(49 cards)
what are your main differentials you should have for azotemia in food animals?
dehydration, septic shock, bacteremia, nephrotoxins, pyelonephritis, leptospirosis, & urolithiasis
what defines azotemia?
elevation in creatinine & BUN
what defines pre-renal azotemia in food animals? what is seen clinically?
decreased glomerular perfusion (dehydration)
characterized by azotemia, USG > 1.025, urine:serum urea > 20:1, & urine: serum creatinine > 30:1
sunken eyes, elevated skin tent time, depression/decreased/absent suckle reflex
what defines renal azotemia in food animals?
any hemodynamic or toxic cause that leads to marked hypotension so they kidneys lose the ability to concentrate urine in the face of azotemia
what are some examples of hemodynamic causes of renal azotemia?
septic shock, hemorrhage, & severe fulminant diarrhea
what is the pathophysiology of hemodynamic causes of acute renal failure resulting in renal azotemia?
marked hypotension and/or release of endogenous pressor agents that have the potential to initiate hemodynamically mediated acute renal failure (starts as pre-renal)
severe hypotension results in the release of renin & activation of AT II which constricts the afferent glomerular arterioles
endotoxins damage the endothelium - promotes the clotting cascade
partial occlusion of renal vasculature decreases renal blood flow (bloat)
erythrocyte aggregation which occurs with high PCV & low blood flow can potentiate local renal hypoperfusion
what are some examples of nephrotoxins that cause acute renal failure in food animals?
medications - aminoglycosides/tetracyclines
endogenous - myoglobin/hemoglobin
plants - oak, pigweed, & halogeton
mycotoxins - aflatoxin
heavy metals - mercury, arsenic
what is the pathophysiology of most toxins causing acute renal failure?
most nephrotoxins damage kidneys by causing acute tubular necrosis but the basement membrane remains intact
what clinical signs are seen in food animals with acute renal failure?
polyuria/oliguria/anuria, depression, & anorexia
what derangements are seen on a chemistry panel of a cow in acute renal failure?
azotemia, metabolic alkalosis (low sodium, low chloride, hypo/normokalemia, hypocalcemia, hypo/normophosphatemia, & hypermagnesemia)
how is acute renal failure diagnosed in a cow?
low USG, discolored urine, proteinuria, sediment (casts degrade rapidly), & use fractional excretion of sodium to determine renal function
k is low because ruminants lose it in their saliva - metabolic alkalosis
BUN: creatinine ratio < 10:1
urine: serum urea < 20:1 & creatinine < 30:1
is a cbc useful for evaluating a cow for acute renal failure?
nope - won’t tell you much
what value on a chemistry panel is a prognostic indicator for a cow with acute renal failure?
magnesium - if greater than 3X, is bad!
how is fluid therapy monitored in oliguric/anuric animals with acute renal failure?
carefully monitored via CVP’s & daily weight gain
how is oliguria corrected in a cow in acute renal failure? what drugs should be avoided?
after fluid therapy & electrolyte replacement - mannitol 20% IV or furosemide 2 mg/kg IV
avoid anti-prostaglandin drugs (banamine)
what therapy is used for cows with acute renal failure?
correct the predisposing problem, replace fluid volume deficits, correct electrolyte & acid base imbalances, correct oliguria if present, & caloric support
how many nephrons must be lost before clinical signs are seen in a cow with CKD?
at least 75% of nephrons must be lost to get clinical signs
what is the pathophysiology of CKD in cows?
may be a result of an initial acute disease/residual damage or glomerular/tubulointerstitial disease
as renal function decreases, there is a decline in GFR - solutes that are normally eliminated from the body are retained (BUN, creatinine)
increased solute filtration filtration & diuresis in surviving nephrons along with concurrent tubular disease impedes normal resorption of water (leads to pu/pd)
what are some examples of causes of CKD in cows?
history or previous sepsis, diarrhea, etc
glomerular disease - amyloidosis
tubulointerstitial diseases - pyelonephritis
what are the general clinical signs associated with CKD in cows?
weight loss, anorexia, pu/pd, kidney may palpate abnormally on rectal, & severe protein loss may lead to SQ edema
what food animals are susceptible to oak toxicosis? which ones aren’t?
cattle & sheep!!!
goats aren’t affected!!!
what is the pathophysiology of oak toxicosis?
metabolites of gallotannins cause precipitation of proteins into the gi tract & kidneys
what are the predisposing factors of oak toxicosis?
weather changes, shortage of forage, & younger animals
what are the clinical signs associated with oak toxicosis?
anorexia, depression, ruminal atony, & dehydration
constipation with hemorrhagic diarrhea after
hematuria, polyuria, oliguria
ascites, hydrothorax, tenesmus, & swollen peri-anal area
