Urinary System III Flashcards
What are the anomalies of development with the kidney?
- Renal aplasia
- Renal hypoplasia
- Ectopic kidney
- Renal fusion
Renal aplasia
- Unilateral or bilateral
- you can live with half a kidney
Renal hypoplasia
- Decreased renal mass
o Stimulates the other kidney to undergo compensatory hypertrophy - Should NOT have evidence of scarring
o Often pitted kidneys in young animals is misdiagnosed as hypoplastic, even though it probably represented progressive juvenile nephropathy or dysplasia - If both hypoplastic=can have renal failure
Ectopic kidney
- Kidney within subcutaneous tissue
- *between the stomach and liver
- Rare in domestic animals
- Usually renal function is normal
o But at higher risk for renal failure - *if ureter gets kinked can lead to HYDRONEPHROSIS
Renal fusion
- Happens embryologically
- Renal function is normal
- “horseshoe kidney”
Renal dysplasia
- Disorganized development of renal parenchyma due to anomalous differentiation
- Congenital
- YOUNG ANIMALS present with renal failure
- Unknown cause (viral, random hereditary abnormality
- *made histologically NOT grossly
3 causes of dysplasia in/of any organ?
- Hereditary
- Viral infections
- Idiopathic
What does renal dysplasia look like grossly?
- Small
- Misshapen
- *can look exactly the same as end stage kidney
o Important DDx in a YOUNG dog with renal failure - **diagnosis it histologically
Progressive juvenile nephropathy
- YOUNG DOG DISEASE (as young as 4 months)
- Runs in families of dogs and in specific dog breeds
- Hereditary
- *chronic progressive renal disease leading to severe bilateral renal fibrosis
- Grossly looks the same as renal dysplasia
What are the specific breeds of dogs have progressive juvenile nephropathy?
- Samoyeds
- Shih Tzu
- Bull terriers
- Minatare schnauzer
Renal cysts
- Dilated nephron structure filled with water fluid
- Acquired: secondary to fibrosis
- Congenital: a few is ‘normal’
Renal cysts secondary to fibrosis
- Fibrosis squeeze renal tubules=leads to obstruction and causing a backflow of urine causing cysts
Polycystic kidney disease
- Many cysts in a kidney with young animals (in liver and pancreas as well)
- Inherited as an autosomal dominant trait in:
o Families of Persia cats
o Bull terrier - Happens in many species
- *can lead to renal failure
Renal congestion
- Difficult to recognize grossly b/c of colour of kidney
- Ex. R. sided heart failure
What are some examples of what causes renal hemorrhage?
- DIC
- Bacterial septicemia
o Receives lots of blood=excellent place to culture (spleen and liver as well) - Viral disease
What is a young puppy that died acutely with ecchymotic renal hemorrhages characteristic of?
- Canine herpesvirus-1 infection
o In utero or after birth - *multisystemic=other organs as well
Renal infarction: cause and appearance
- Obstruction of renal vasculature
- *appearance depends on TYPE of obstructing material and size of affected vessel and duration
- *often wedge shaped=arcuate OR interlobular
What will septic infarcts become?
- Abscess
- *AV valve endocarditis
- Cattle: A. pyogenes
- Pigs: Erysipelothrix rhusiopathiae
- Small animals: Staph
What will thrombosis of a trunk of a renal artery produce?
- Total OR subtotal necrosis of the kidney
Vessel size: arcuate artery infarction
- Wedge of BOTH cortex and medulla
Vessel size: interlobular artery infarction
- Wedged LIMITED to cortex
Renal infarct: acute appearance
- Red and bulging
- *significant for the case NOT the kidney
o Look at heart (left AV valve)
Renal infarct: acute to subacute appearance
- Pale and bulging
Renal infarct: subacute appearance
- Pale & bulging with a rim of hyperemia
Renal infarct: chronic appearance
- Pale depressed with loss of tissue
o Necrosis - *INCIDENTAL FINDINGS=NOT SIGNIFICANT
o Unless they are a chronic abscess
What are the causes of renal papillary/medullary crest necrosis?
- NSAIDs by inhibiting PGE-2 which is a vasodilator
a. Often dehydrated animal - Space occupying mass
a. Renal medullary vessels are very THIN WALLED
What is the sequelae to renal papillary/medullary crest necrosis based on?
- Severity
o If small=resolution
o If severe=acute renal failure - *chronic renal failure can occur if lesion heals by fibrosis and is severe enough to result in decreased ability to concentrate urine
What is hydronephrosis?
- Dilation of renal pelvis and calyces associated with progressive atrophy and cystic enlargement of kidney
What is the cause of hydronephrosis?
- Urinary obstruction
o Acquired: urinary caliculi, enlarged prostate, cysitis
o Anomalous - *depends on location of obstruction
- *unilateral or bilateral
Hydronephrosis ‘outcome’ depends on location of obstruction
- Ureteral obstruction: severe unilateral hydronephrosis
o Severe as lesion, but incidental finding - Lower obstruction: bilateral hydronephrosis with less severe kidney lesions
o *early death from uremia
**What is the importance of glomerular disease?
- Interference with glomerular blood flow and decreasing formation of ultrafiltrate IMPARIS PERITUBULAR PERFUSION
a. May cause loss of entire nephron - Glomerular permeability may be altered=leading to proteinuria
a. With NO inflammation
What is glomerular disease an important cause of in dogs and cats?
- Chronic kidney disease in dogs, occasionally cats
- Acute kidney injury
- *can lead to nephrotic syndrome
What in particularly indicative of glomerular damage?
- Proteinuria, occurring in absence of UT inflammation
If high proteinuria, what are the 2 things that cause cause it?
- Glomerular disease
- Amyloidosis
o Which can lead to glomerular disease later on
What are the 3 hallmarks of nephrotic syndrome?
- Hypoalbuminemia
- Generalized edema
- Hypercholesteremia (not totally sure why)
Why can animals with glomerular disease be hypercoagulable?
- Have loss of antithrombin III
o Often results in systemic thrombosis, most commonly respiratory thrombosis
Glomerulonephritis
- Subtype of glomerular disease
- Important cause of renal failure in dogs and cats
- *disease within glomerulus with extension to tubules and interstitium
- *NOT a final diagnosis=tells you that there are Abs attacking the glomerulus due to something outside the glomeruli (inciting cause may NOT be found)
What is the pathogenesis of glomerulonephritis?
- Deposition in glomeruli of circulating immune complexes UNRELATED to glomerular components (aka IMMUNE COMPLEX glomerulonephritis)
- From formation in situ of Abs against glomerular BM (rare in domestic animals)
a. Abs are produced against the BM of glomeruli
What can cause immune-complex glomerulonephritis in cats?
- FeLV
- FIP
- FIV
- Neoplasia
What can cause immune-complex glomerulonephritis in dogs?
- Chronic bacterial diseases
- Endometritis (pyometra)
- Immune-mediate polyarthritis
- -neoplasia
What are the 3 types of glomerulonephotis? (histology reports)
- Membranous
- Proliferative
- Membranoproliferative (most common)
Proliferative GN
- Increased cellularity of glomerular tufts
- *blue dots in glomerulus
- **most common variant in HORSES
Membranous GN
- Diffuse glomerular capillary basement membrane thickening
- *most common type in CATS
Membranoproliferative GN
- Hypercellularity and thickening of capillary BM
- *most common type in DOGS
What can be done to highlight the deposits within glomeruli?
- Immunofluorescence
- PAS stains
What is the gross appearance of acute GN?
- Can give cortex a lumpy appearance
- But can’t tell fully by GROSS appearance
- *white nodules on surface of cortex (=affected glomeruli)
