PRAC: Tarc Path Urinary Tract Flashcards
How does hydronephrosis appear PM?
- dilated thin pelvis with fibrosis of the tissue (d/t compression of interstitial BVs v renal blood flow -> ischaemic necrosis)
- Tubules undergo degeneration and/or atrophy and necorsis -> pale radiating columns or rays of fibrotic tissue
How may animals with hydronephrosis compensate?
- hypertrophy of the other kidney providing it is a unilateral disease
- if bilateral disease cannot compensate -> renal failure
Causes of hydronephrosis?
- intraluminal occlusion of UT by calculi, mucus plugs, blood clots, neoplasia, inflame cell s
- external compression by neoplasia, inflame, circumferential fibrosis, vaginal ± uterine collapse
- congenital (ureter aplasia, ectopic ureters etc.)
- trauma to urinary tract
- bladder paralysis
What would you suspect in a dog, died after short illness and near signs that was a guard dog in a breakers yard, drinks from puddles. On PME kidney has indistinct pale striations in inner zone of cortex (tubular degeneration and necrosis) but is not fibrotic. On histopath there is multifocal tubular dilation, degenerate tubular epithelial cells are distended with intracytoplasmic vacuoles, many tubules contain crystalline material. How can this be more definitively dx?
- ethylene glycol poisoning
- 2D image taken using polarised light shows presence of intratubular crystals
Outline pathogenesis of ethylene glycol toxicity
- oxidised by liver (alcohol dehydrogenase) to toxic metabolites inc glycol acid and oxalate
- filtered by glomeruli directly causing acute tubular necrosis
- formation and precipitation of calcium oxalate crystals in renal tubular lumens, tubular epithelial cells and the interstitium causes internal obstruction and mechanical damage
How may herbivores succumb to a similar condition to ethylene glycol toxicity?
eating oxalate containing plants
How does pyelonephritis present in cows?
- recently calved
- v milk yield
- passing small flecks of blood in last phase of urination
- stiff when walking and hunched back
- grunted with pain in rectal exam of lumbar area
- ^ temperature
What is seen PM with pyelonephritis?
- renal calyces contain supparative exudate bordered by rim of red hamaemorrhage
What pdf pyelonephritis in cows?
- it is an ascending bladder infection
- trauma @ parturition van compromise defence mechanisms of the ureters
- stress of parturition, peak lactation, high protein diet ^ risk (high protein ^ pH urine allowing easier colonisation of urinary tract)
What bacteria can cause pyelonephritis in cows?
- E. Coli
- Arcanobacterium pyogenes
- Corynebacterium renale
± opportunistic staph and strep - Uropathogenic E. COli and corynebacterium renale produce urease (hydrolyses urea -> ammonia) dmaage to urinary tract mucosa and ^ urine pH
What other species are affected by pyelonephritis postpartum?
Sows
How does acute tubular necrosis appear histologically?
- deffuse degernation and encores of epithelial cells of convoluted tubules
- glomeruli and collecting ducts often spared
- BM may or may not be retained
- no reactive inflammation or scar tissue would indicate recent cell death
What can cause acute tubular necrosis?
- ischaemia
- nephrotoxins
- inflammation
- infectious agents
What determines how well the kidney heals after acute tubular necrosis?
- whether BM is intact
- if in tact, forms a scaffold for cellular regeneration potential for renal function to be maintained
- if lost, no scaffold -> fibrous scar tissue formation and v renal function
When is basement membrane damage most commonly seen?
- with iscaemic insults
- (cf. toxins which damage epithelium and may well leave BM in tact)
