Urinary System Flashcards
What are the possible causes of renal dysplasia?
- congenital infections
(feline panleukopenia, canine herpesvirus, bovine viral diarrhea) - autosomal dominant in Suffolk sheep
- hypovitaminosis A in swine
- intrauterine ureteral obstruction in swine and calves
Describe the typical appearance of renal cysts
- fluid filled
- lined by flat or cuboidal epithelium
Describe the appearance of a polycystic kidney
- numerous variable-sized cysts in both cortex and medulla
- on cut surface, have a honeycomb like appearance
- cysts filled with colorless fluid
What can happen to the renal cysts?
- may grow slowly or remain static
- may increase in size and/or number, causing compression atrophy
What is a horseshoe kidney?
- congenital malformation that results from fusion of the cranial or caudal poles of the kidney
- incidental finding
What causes hemoglobin in the kidneys?
What is the gross and micro appearance?
- severe intravacular hemolysis and hemoglobinuria
- dark red to black kidneys
- orange casts in tubule lumens
What causes myoglobin in the kidneys?
Give two examples
What is the gross appearance?
- occurs when high levels of myoglobin are filtered into the tubules
- Rhabdomyolysis and equine paralytic myoglobinuria
- dark red to black kidneys, and dark red urine
What is the gross appearance of kidneys with lipofucsinosis?
dark brown to black kidneys
What is the cause of bile pigment in the kidneys?
What is the gross appearance?
- in obstructive jaundice or liver disease, the kidneys excrete conjugated bilirubin
- kidneys are yellow-green
What is the gross appearance of hyperemia and congestion?
What are the common causes?
- bright or dark red kidneys
- result of prolonged prostration and circulatory failure
What is the common cause of general renal hemorrhage?
result of vasculitis or vascular necrosis
What are possible causes of renal petechia and ecchymosis?
- extensive vascular injury or platelet consumption leading to DIC
- acquired or congenital clotting defects
- viremia (hog cholera, african swine fever, canine herpesvirus)
- bacteremia
- toxins
What are common causes of renal infarction?
- associated with thrombosis of renal vessels
- valvular endocarditis
- prolonged ischemia
When is renal infarction commonly seen?
- cattle and pigs with vegetative valvular endocarditis of the left heart
- cats with left atrial thrombosis associated with cardiomyopathy
- dogs with renal amyloidosis due to loss of plasma anticoagulants
- endotoxin related thrombosis
Describe primary amyloidosis
- very rare
- due to deposition of amyloid AL, derived from Ig light chains produced by abnormal plasma cells
Describe secondary amyloidosis
- most common
- deposition of amyloid AA that originates from serum alpha-globulin
- associated with chronic antigenic stimulation
Describe the gross appearance of amyloidosis
- kidneys are enlarged, pale, and have a finely granular surface
- waxy on cut surface
Describe the microscopic appearance of amyloidosis
- deposition of pink, amorphous material in the glomeruli or medullary interstitium
Describe familial renal amyloidosis
- occurs in Abyssinian cats and Shar pei dogs
- characterized by medullary deposits of amyloid, with fibrosis and papillary necrosis
- can lead to thrombosis of pulmonary arteries and renal veins
What is renal cortical necrosis?
Describe the gross appearance
- an acute and severe ischemia of the renal cortex due to vasospasm of cortical vessels
- cortex has mosaic appearance with intermixed areas of red and yellow
What are the causes of renal medullary necrosis?
- localized ischemia of renal medulla
- amyloidosis in cats
- pyelonephritis
- diabetes mellitus
- urinary obstruction
- anti-inflammatory and analgesic drugs
Describe the histological appearance of chronic nephrosis
- fibrosis
- tubular loss
- architectural disorganization
- regeneration
- limited inflammatory response
Describe the histological appearance of acute nephrosis
- swelling of tubular epithelium
- cytoplasm may be vacuolated
- nucleus pyknotic, karyolytic, karyorrhectic
- tubules may be hypocellular, dilated, and contain necrotic debris and hyalinized casts
What are causes of nephrosis?
- ingestion of exogenous substances (which can precipitate as crystals)
- heavy metals
- insecticides
- nephrotic plants (pigweed and oak)
Describe embolic nephritis
- cause
- appearance
- caused by bacteremia
- multifocal suppurative glomerulitis
- bacterial colonies in glomerular and interstitial capillaries
- chronic renal microabscesses may result
What are the two main mechanisms of glomerulonephritis?
- deposition of Ag/Ab complexes
- autoantibodies directed against GBM
What are the 3 morphologic types of glomerulonephritis?
- membranous: thickening of BM
- proliferative: increased cellularity
- membranoproliferative: combination of both
What is White-Spotted Kidney?
- multifocal interstitial nephritis
- residual lesion of E. coli bacteremia
What is pyelonephritis?
What is the pathogenesis?
inflammation of the renal pelvis and parenchyma
- originates from ascending bacterial infection
- ascends ureters, invades renal pelvis, and enters parenchyma
What are predisposing factors to pyelonephritis?
- urinary obstruction
- abnormal vesico-ureteral reflux
- cystitis
Describe the gross appearance of pyelonephritis
- suppurative exudate in pelvic cavity
- partial destruction of medulla
- irregular discoloration of cortex
- scarring and fibrosis
- inflammation in ureter and bladder
Describe the microscopic appearance of pyelonephritis
- large number of neutrophils and bacteria within tubule lumens, and necrosis of tubular epithelium (acute)
- white bands of scar tissue, fibrosis, loss of tubules (chronic)
What is granulomatous nephritis?
- a form of chronic nephritis characterized by predominance of macrophages
- dry form of FIP
What are some etiologies of granulomatous nephritis?
- virus (corona virus)
- fungal organisms
- bacteria
- parasite migration (H. gingivalis, saprophytic nematode, dictiophyma renale, stephanurus dentatus)
What is hydronephrosis?
What is the cause?
abnormal and permanent dilation of the renal pelvis and calyces, with progressive atrophy of renal parenchyma
- due to increased pressure following partial or complete obstruction of urine outflow
What is urolithiasis?
- the process or formation of solid or semi-solid concretions anywhere in the urinary collecting system
What are predisposing factors to urolithiasis?
- increased urine concentration of stone constituents
- low urine volume
- urine pH
- urinary tract infections
- diets high in phosphate
- high level of silica on pastures
What are the possible conequences of urolithiasis?
- hydronephrosis if lodged in ureter
- chronic cystitis or bladder distention and rupture if lodged in urethra
- acute hemorrhagic urethritis
What is the main cause of familial renal diseases?
- abnormal structure or function
What is End-Stage Kidney?
a term used to describe kidneys that are severely affected by chronic inflammation and fibrosis
- kidneys are shrunken, pale, and firm
Define renal disease
any deviation form normal renal structure or function
Define renal failure
the inability of the kidney to maintain normal function
- requires 70-75% loss of renal function
What is the cause of Hemorrhagic Ulcerative Gastritis?
- uremia
- arteriolar necrosis with mucosal infarction and mineralization of the gastric glands and submucosal vessels
What is mucoarteritis/endocarditis?
Describe the gross appearance
- a non-inflammatory condition due to deposition of glucosaminoglycans with subsequent fibrinoid degeneration of connective tissue
- opague, light yellow roughened endocardial plaques
How does pulmonary edema occur?
damage to the blood-air barrier and plasma fluid leaks into the alveoli
What causes secondary renal hyperparathyroidism?
- abnormal renal function results in excessive retention of phosphorus
- parathyroid glands activated to increase calcium
What are possible causes of cystitis?
- bacterial infection
- formation and accumulation of uroliths
- exposure to toxic compounds (blister beetles, bracken fern, cyclophosphamide)
What are the characteristics of chronic cystitis?
- mucus metaplasia of transitional epithelium
- multifocal lymphoid hyperplasia (follicular cystitis)
- formation of mucosal polyps (polypoid cystitis)
What are possible causes of feline lower urinary tract disease?
- diet high in magnesium and phosphate
- alkaline urine pH
- decreased fluid consumption
What are three examples of primary epithelial tumors?
- renal adenoma
- renal adenocarcinoma
- renal cystadenocarcinoma
What are three examples of primary urinary tumors?
- nephroblastoma
- transitional cell papilloma
- transitional cell carcinoma
