Urinary Last Section Flashcards
Why is the renal pelvis more susceptible to infections?
- Low blood supply (lower ability to mount an inflammatory response)
- Higher tonicity inhibit neutrophil function
- Ammonia inhibits complement function
What are the causes of pyelonephritis?
- Bacteria: E. coli
o Ascending infection from lower UT - Ruminants:
o Corynebacterium renale
o E. coli
o T. pyogenes - Pigs
o Actinobaculum suis
What is the gross appearance of chronic pyelonephritis?
- *pus in renal pelvis
What is the gross appearance of acute pyelonephritis?
- White spots on surface when you remove capsule
- lines radiated form renal pelvis to the cortex
Interstitial nephritis or tubulointerstitial nephritis (TIN): 2 types
- non suppurative lymphoplasmacytic IN
- granulomatous IN
What are some examples of what gives you LIN?
- Leptospirosis (LIN)
- Porcine postweaning multisystemic wasting syndrome (PMWS) (LIN)
- White spotted kidney (LIN)
- Feline infectious peritonitis (GIN)
Leptospirosis
- Rare
- LOVES the kidney
- L. interogans
- 3 forms: acute, subacute, chronic
- *species specific: serovars adapted to certain species
o Wont cause disease in that species, but if affects other species=see leptospirosis
Acute leptospirosis
- Liver damage + RBC hemolysis
o Icterus
o Hemoglobinurea
Subacute leptospirosis
- Renal disease LEADING TO RENAL FAILURE IN DOGS!
o Other species do NOT progress to renal failure
Chronic leptospirosis
- Abortion
- Stillbirth
- *most important in livestock
What does lymphoplasmacytic interstitial nephritis look like grossly?
- White spots on surface
o In cows=incidental due to old E. coli septicemia
o *first differential in pigs: PCV-2
Porcine postweaning multisystemic wasting syndrome
- Cause: porcine circovirus-2
- *can cause lymphoplasmacytic interstitial nephritis
- Kidney is NOT the primary target
White spotted kidney: significance, species, reasoning
- *incidental finding
- Can see in young calves
- Old E. coli septicemia=not related to cause of death
White raised creamy spots on cat kidney, what could it be?
- Lymphosarcoma: older cats
- FIP: cats less than 3 years old
Feline infectious peritonitis
- Cause: feline coronavirus
- *centered on or close to vessels
- *multifocal pyogranulomatous nephritis
Hypercalcemic nephropathy
- Renal disease secondary to hypercalcemia
- Can lead to renal failure
What are the cause of hypercalcemia?
- Primary hyperparathyroidism
- Nutritional secondary hyperparathyroidism
- Granulomatous inflammation
- Hypoadrenocorticism
- Neoplasia
- Vitamin D toxicity
Renal neoplasia
- Uncommon (<1%)
- Often malignant
- *more commonly get tumor metastasis to kidney
Renal adenocarcinoma
- Embryonic tumor
- YOUNG animals
- In swine or chickens=incidental finding at slaughter
o Usually unilateral - Rarely malignant: except up to 50% in DOGS have metastasized
Lymphosarcoma
- Metastasis to kidney
- MOST common tumor type found in kidney of CATS
- Differential: FIP
- *creamy white lesions
Females urethra
- Short and close to skin, GI and genital tract
- *predisposed to ascending infections
Males urethra
- Long and narrow
- *prone to obstruction
Urinary bladder before death
- Contracts and appears THICK
- If mucosa is smooth and shiny=normal (even if thickened)
- Urine should be clear
What are the defence mechanism of the lower UT?
- Urine flow
- *urine is not favorable for bacterial growth
Why is urine not favorable for bacterial growth?
- Acidic pH, especially in carnivores
- High urine osmolality=bacteriostatic
- Protective mucous coating (slippery=reduces bacterial attachment and damage when crystals form)
- Urothelium routinely slough and will void attached bacteria
What is an ectopic ureter?
- *ureter empties to abnormal location (urethra) and not the bladder
- Most common in DOGS (more in females)
o Incontinence (urine dribbling) at birth - *may cause skin irritation and hyperemia
Patent urachus
- Fetus pees into allantoic cavity through the urachus which connects the bladder to the allantoic cavity
o *should close at birth - Most common in foals
- *urine dripping from umbilicus
- *predisposed to secondary infection
- *rupture uroperitoneum and chemical peritonitis
What are some acquired lesions of the lower UT?
- Hydroureter: OBSTRUCTION
- Dilation of bladder
- Rupture of bladder (cystorrhexis)
Dilation of bladder
- Urethral obstruction=MAIN CAUSE
o Often leads to bladder rupture before hydronephrosis develops - Neuroparalytic: less common
Rupture of bladder (cystorrhexis)
- Urethral obstruction
- Pelvic trauma
- *results in chemical peritonitis and uroabdomen
- **DORSAL SURFACE=weaker
Urolithiasis
- Presence of calculi in urinary passages
- Can be found anywhere
o Most common: ureter
o Least common: renal pelvis - Common in dogs, cats and ruminants=IMPORTANT
- Less common in horses and pigs=less important
What is a predisposing factor for urolithiasis?
- Sufficient amounts of cacluolgenic material
- Urinary pH
- Reduced water consumption
- Bacterial infection
Calculi
- Highly variable in appearance
- Can’t tell composition on gross examination
- Stone analysis
What might lead to sufficient amounts of calculogenic material in urine?
- Abnormal metabolism: uric acid in Dalmatians
- Abnormal processing in kidney: defective cysteine absorption in some dog breeds)
- High levels in diet: ex. silica
Struvite calculi (magnesium ammonium phosphate)
- Most important in DOGS (cats, cattle)
o Females more than males - Associated with bacterial infections=dogs
- Dry food with high CHO=cats
- *like alkaline conditions (high pH)
What happens in dogs that get struvite calculi?
- Bacterial ureases
- Ammonia (increase pH)
- Decreased struvite solubility
- Calculus formation
Oxalate crystals
- Second most common type in dogs
- *most common in cats
o Cause unknown but likely diet - *likes acidic conditions
What is the condition of the urinary bladder uroliths in horses known as?
- Sabulous urolithiasis
o “sand-like accumulation”
o Sludgy white material
What are the consequences of urolithiasis?
- Pressure necrosis at point of impaction (necrosis and hyperemia)
- Obstructive disease
Ureter obstruction (from urolithiasis)
- Painful
- Hydronephrosis of kidney
- *fatal if bilateral
Urethra obstruction (from urolithiasis)
- Fatal if complete and unresolved
What is cystitis?
- Inflammation of urinary bladder
- Usually bacterial cause (ex. E.coli)
o Same as with pyelonephritis
What are the predisposing factors to cystitis?
- Female
- Urine stasis obstruction
- Trauma
- Glucosuria-emphysematous cystitis
- Compromise of immune system (ex. Cushing’s)
- Prolonged antibiotic therapy
Cystitis
- Bacteria associated with cystitis are same as those that cause pyelonephritis
- Rectal, dermal or genital flora
- *often ascending and rarely results from septicemia
- More common in FEMALES
- Diabetes is a predisposing factor as bacteria love glucose
- Cushing’s disease: steroids give you immunosuppressive and insulin resistance
- *most of tract is sterile except DISTAL part=normal flora
Acute cystitis in cows: 4 causes
- C. renale
- E. coli
- T. pyogenes
- Bracken fern poisoning (turn to chronic and then neoplasia)
- *horses: ingest blister beetles=cantharidin
Chronic cystitis: 2 forms
- Lymphoid cystitis: white spots on surface
- Polypoid cystitis=bulging nodules
Toxic cystitis in horses
- Blister beetle toxicity
o Ingest beetle and get GI ulcerations
Enzootic hematuria in cattle
- Secondary to chronic bracken fern ingestion
- Several toxic components
o Thiaminase
o Numerous carciongens
o ‘bleeding factor’ - Urinary bladder hemorrhage and ulceration
- *chronic hematuria and anemia
- Bladder tumors
o Benign malignant
o Epithelial and malignant
o Progress to transitional cell carcinoma
Feline lower UT disease
- MALE CATS, castrated (young to middle age)
- Idiopathic
- Chronic condition
- No bacteria isolated
- Calculi sometimes found
Neoplasia of lower UT
- Rare (<1%)
- Most commonly found in urinary bladder
- Most important in dogs, cats and cattle (enzootic hematuria)
- *most are epithelial and malignant
- ***transitional cell carcinoma=MOST COMMON
What is botryoid rhabdomyosarcoma?
- “grape like”
- Rare tumor of very young, large breed dogs
- *malignant
- Thought to be embryonic origin
What is the most common tumor of the lower urinary tract?
- Transitional cell carcinoma
