Renal disease Flashcards
What are some causes of acute renal failure?
Hemodynamic or septic shock (can be secondary to abomasal volvulus, toxic mastitis, septicemia, etc.)
What are some causes of renal tubular nephrosis?
Oxytetracycline, aminoglycoside antibiotics
What are some causes of hemoglobinuria and myoglobinuria?
Copper toxicosis, Leptospirosis, water intoxication, white muscle disease
List miscellaneous nephrotoxins
Zinc, mercury, chlorinated hydrocarbons, vitamin D containing plants (Cestrum diurnum), beets, rhubarb, pigweed, oak, brackenfern
What is the most common and important disease of the ruminant urinary tract?
Urolithiasis
Which animals are predisposed to urolithiasis?
Males castrated at a young age
What time of year does incidence of urolithiasis increase?
Late fall and winter and during arid months of summer
Where do uroliths typically lodge?
Distal aspect of the sigmoid flexure or the urethral process
What are the types of uroliths that ruminants develop?
Struvite, calcium carbonate, silica, calcium oxalate
Describe struvite uroliths
Magnesium ammonium phosphate; most common urolith in feedlot animals and animals on high concentrate diets, usually see multiple, soft, amorphous stones or “sludge” in the urinary tract
Describe calcium carbonate
Can occur in alkaline or acidic urine, possibly predisposed by feeding of urine acidifiers (due to increased calcium excretion), appear as spherical golden stones of varying signs, very radio-opaque, will NOT dissolve
Describe silica stones
Occur in animals eating feeds with high silicate (sand) concentrates- typically Western US, stones are single, hard, and damage urethral mucosa, high dietary calcium may predispose
Describe calcium oxalate
Not very common, primarily seen in sheep grazing on lush clover or legume, high dietary calcium and oxalate may predispose
What are risk factors for developing uroliths?
Decreased salt/water intake, urinary stasis, UTI (rare), high urinary pH (silica and phosphate), high estrogen, vitamin A deficiency
What clinical signs are consistent with urolithiasis?
Arched stance, treading, swishing of tail, kicking at belly, stranguria, posturing, urethral pulsations, distended bladder, colic signs, depression, lethargy, anorexia
How is urolithiasis diagnosed?
Clinical signs, azotemia and hyperkalemia on chemistry panel, hyponatremia chloremia and calcemia if bladder ruptures, abdominal paracentesis (cre 2x blood), abdominal ultrasound
How is urolithiasis treated?
Amputation of urethral process plus dissolution or surgical removal
PU not preferred
Tube cystotomy is only option if you want to maintain breeding ability
How can urolithiasis be prevented?
Urinary acidification (but may predispose to calcium carbonate stones), increase salt in ration, delay castration, urolith specific therapy (Ca:P ratio for struvite etc.), avoid pelleted feeds, remove source of excess minerals (silica)
What are the primary causative agents of pyelonephritis?
Corynebacterium renale and E. coli
Describe the pathophysiology of pyelonephritis
Adhesion of the organism to vulvar mucous membranes initiates infection, bacteria then ascends urinary tract to kidneys
When does pyelonephritis occur most frequently?
Early lactation in older cows
What pH does E. coli prefer? What pH does C. renale prefer?
E. coli- <6
C. renale- >7
What are the clinical signs of pyelonephritis?
Arched stance, treading of feet, swishing of tail, kicking at belly, fever, anorexia, depression, hematuria, pyuria, stranguria, pollakiuria, dysuria
How is pyelonephritis diagnosed?
History and clinical signs, rectal palpation of swollen lobulated kidney with thickened bladder and ureter, urinalysis with WBCs and bacteria, renal failure findings on chemistry panel, neutrophilia, hyperfibrinogenemia, >10,000 CFU/ml urine, ultrasound showing distension of renal pelvis with abscessation
How is pyelonephritis treated?
If animal is not valuable, cull
Antibiotics (ceftiofur IM or procaine penicillin) for 4-8 weeks, IV fluids for diuresis, unilateral nephrectomy (last resort)
Which animals tend to develop amyloidosis?
Older cattle with chronic inflammatory disease (TRP, foot abscess, chronic mastitis, etc.)
What clinical signs are associated with amyloidosis?
Chronic history of weight loss and depression, chronic diarrhea, uremia, polyuria, foamy urine due to high protein concentration
How is amyloidosis diagnosed?
Urinalysis with massive persistent proteinuria, leukocytosis, hyperfibrinogenemia, histopathology
What is the treatment for amyloidosis?
None- supportive care until salvage
What are the clinical signs of glomerulonephritis?
Usually no clinical manifestation but can cause renal failure or nephrotic syndrome
What are potential causes of glomerulonephritis?
Any infection of low pathogenicity that can produce persistent antigenemia, especially viruses, potentially modified live vaccines
What is the toxic agent of brackenfern?
Ptaquiloside
What disease develops with chronic exposure to brackenfern?
Enzootic hematuria
What effect does ptaquiloside have on the bladder?
Can produce small polyp-like tumors and bleeding masses (hemangiomas)
What clinical signs are associated with brackenfern toxicosis?
Hematuria, anemia, mucous membrane hemorrhages, hyphema, melena
What is the principle toxin of oak?
Gallotannin
Why is oak toxicosis not a big problem in ruminants?
They don’t find oak very tasty
What are the clinical signs of oak toxicosis?
Depression, polydipsia, black diarrhea, teeth grinding, abdominal pain, liver and kidney damage, hematuria, icterus, dehydration
