Lecture 6 - Pathology of the urinary system IV

What is an ectopic ureter? What species is it most common in? What gender?

-Ureter empties into another part of the urinary/genital tract

-most common in dogs

-Affects females more than males

What is a patent urachus? What does it result in? What species is it most commonly seen in?

-Incomplete closure of the urachus causing dribbling of urine

-May result in infection/abscess

-Commonly seen in horses but can affect all species

What does diverticula of the urinary bladder cause? What is it caused by? Where is it commonly seen?

-Causes urine stasis in diverticulum leading to persistent infection and chronic inflammation

-Can be acquired, caused by urine outflow obstruction, or pressure changes

-Usually seen at apex of bladder

What can a dorsal retroflexion of a bladder be seen in?

-Male dogs due to prostatic enlargement or constipation

-Cows, sows, bitches with uterine prolapse

-Perineal hernias in old dogs

What can eversion of a bladder be seen in? What is it caused by?

-Females (most frequently mares)

-Secondary to increased intra-abdominal pressure (parturition)

What is a prolapse of the urinary bladder?

Displacement through rent in vaginal wall

What can urinary bladder distension be caused by?

-Obstruction

-Neuroparalyitic/neurogenic (spinal cord injury, spinal myelitis, herniated disc)

What can a urinary bladder rupture be caused by?

-Urethral obstruction (most commonly)

-Pelvic trauma or dystocia

How does a urinary bladder rupture occur in foals? Who is most often affected?

-Twists in umbilical cord compresses urachus causing distension of urachus and bladder during parturition

-Males most often affected

What are urolithiasis?

Grossly visible aggregations of precipitated urinary solutes, proteins, debris, and minerals

What are predisposing factors contributing to urolithiases?

-Unusual metabolism

-Dehydration

-Changes in urine pH and composition

-Abnormally high levels of a substance in diet

-Infection

-Obstructions, anatomic anomalies, foreign bodies

What are 5 examples of urolithiases? What animals are they commonly found in?

1. Struvite - dogs, cats, cattle

2. Calcium oxalate - cats, dogs, sheep

3. Silica - pastured ruminants

4. Urate - dogs, rarely cats

5. Cystine - dogs

What are the characteristics of struvite urolithiases? What are they commonly associated with in female dogs?

-Radio-opaque

-Chalky, smooth, easily broken

-Associated with UTIs

What are the characteristics of calcium oxalate urolithiasis?

-Radio-opaque

-Hard, heavy, typically jagged

What are the characteristics of silica urolithiasis?

-Radio-opaque

-Hard, white to dark brown, often laminated

What are the consequences of urolithiasis?

-Obstruction (causes hydronephrosis and bladder distention/rupture)

-Chronic cystitis

-Acute hemorrhagic urethritis

What are the defense mechanisms of the lower urinary tract?

-Sphincters

-Pulsatile flow from kidneys and urinary bladder

-Acidic urine and high osmolality

-Tamm-horsfall mucoprotein

-Local IgA production

What are the predisposing factors to bacterial cystitis?

-Stagnation of urine

-Incomplete voiding

-Urothelial trauma

-Administration of antibiotics/corticosteroids

-Alteration of urine pH

-Glucosuria and proteinuria

-Anatomy (females have a shorter urethra)

What is emphysematous cystitis?

Subset of bacterial cystitis that develops in dogs and cats with diabetes mellitus (results from sugar fermentation)

What are differentials for non-infectious cystitis

-Idiopathic

-Interstitial cystitis

-Blister beetle toxicity

-Chronic cystitis (follicular or polypoid)

What species/age is idiopathic cystitis common in? What is the characteristic cystoscopy feature?

-Cats 4-10yrs old

-Cystoscopy shows submucosal petechial hemorrhages

How are blister beetles toxic? What species are they toxic in?

-Secrete cantharidin causing GI ulceration and necrosis

-Horses

What is chronic cystitis seen with? What are the two anatomic forms?

-Seen with urolithiasis

-Forms: follicular cystitis and polypoid cystitis

What does the mucosa look like with follicular cystitis?

Studded with small, grey-white nodules

What does the mucosa look like with polypoid cystitis?

Mucosa forms villous folds or polyps (may look similar to transitional cell carcinoma)

What are the clinical findings of neoplasia?

-Hematuria

-Stranguria (straining to urinate)

-Hydroureter/hydronephrosis

What species is renal carcinoma commonly found in? What are possible paraneoplasic syndromes associated with it?

-Dogs, cattle, and horses

-Possible syndromes: nodular dermatofibrosis, polycythemia (increased EPO), hypertrophic osteopathy

What species are nephroblastomas commonly found in? What age?

-Pigs and chickens

-Young animals (except dogs)

What are the characteristics of transitional cell papilloma?

-May ulcerate and contribute to hematuria

-May progress to carcimona

What species and breed is transitional cell carcinomas most common in? Where does it generally metastasize to? Where is it commonly found in the bladder?

-Dogs - scottish terrier

-Metastasize to regional lymph nodes

-Usually found on trigone of the bladder

Which neoplasias are the most common mesenchymal tumor found in dog urinary bladders?

-Fibroma

-Leiomyoma

Which neoplasias are the most common mesenchymal tumors found in dog kidneys?

-Fibrous tumors

-Vascular tumors

What occurs with bracken fern toxicity? In what species?

-Hemorrhagic cystitis and persistent hematuria

-Cattle