Diseases of Urinary System Urinary System AnatomyLocation Kidneys

Diseases of Urinary System

Urinary System • Anatomy/Location – – Kidneys Ureters Bladder Urethra • Function – Remove waste – Maintain homeostasis • acid/base • electrolytes • fluid balance – Hormone production • erythropoietin

Urinary System – Infections usually due to ascending organism – Usually resistant to bacterial infection • • Frequent urination flushes bacteria Urethral/ureteral peristalsis Glucosaminoglycans in mucosa p. H

Feline Cystitis Cause unknown; virus suspected; usually not bacterial; recurrence likely Self-limiting (7 -10 d), so any appropriate treatment appears to help • Signs – Frequent urinations (sm vol) – Hematuria – Dysuria – Inappropriate urination (sinks, tubs are a favorite) • Dx – Urinalysis/culture to r/o bacteria as cause – X-rays to r/o calculi; contrast studies show thickened wall

Feline Cystitis • Rx – Avoid unnecessary antibiotics – Change diet from dry to moist • Salt food to ↑ water intake – Reduce stress from other cats, kids, etc (hiding places) • Client info – Disease is self-limiting – May be recurring problem – No definitive cure – Reduce stress

Canine Cystitis (Bacterial Cystitis) • Signs – – – ↑ frequency of urination Hematuria Dysuria Cloudy urine; abnormal color Frequent licking of urethral area • Dx – Urinalysis: ↑WBC’s, bacteria – Urine culture/sensitivity • Collect by cystocentesis(? ) – Mid-stream collection

Canine Cystitis (Bacterial Cystitis) • Rx – Avoid unnecessary use of indwelling urinary catheters • Use closed system – Antibiotics according to sensitivity • Treat acute infections x 10 -14 d • Subsequent infections x 4 -6 w – Avoid trauma to urinary tract during surgery • Client info – Many uncomplicated urinary tract infections resolve without Rx – Give antibiotics as directed for the time prescribed • Relapses are common due to inadequate treatment – Prostate may be source of recurring infections in male dogs – Urine cultures should be repeated during treatment to assess effect

Close system

Feline Uroliths and Urethral Plugs “Plugged” male cats are commonly seen in SA practice Will be fatal if not relieved • Uroliths (bladder stones) found anywhere in urinary tract – Formed from minerals in diet – Some are radiopaque (Ca++ oxalate, urate, struvite) and can be seen on x-ray – Some are radiolucent and require double contrast (air, dye) • Uroliths damage bladder, making it more susceptible to bacterial infection, hematuria • Uroliths can form plugs in urethra of males – Bladder will fill with urine – Kidneys will stop working – Blood/body will become toxic (azotemic)

Feline Uroliths and Urethral Plugs • Signs (more severe if obstruction has occurred) – – – Hematuria Dysuria/ frequent urination Urinating in strange places (sink, tub) Straining to urinate Vomiting Collapse, death

Feline Uroliths and Urethral Plugs • Dx – Palpation of bladder (obstructed is full and tight) – X-rays may show uroliths on routine films • Double contrast studies may be indicated – Ultrasonography can locate position of urolith – Urolith analysis to determine its constituents Double contrast cystogram (with stones) pneumocystogram

US of bladder stone

Feline Uroliths and Urethral Plugs • Rx – Medical treatment (chronic, non-obstructed) • Dissolve struvite uroliths (most common; ~60%) by acidifying urine and feeding diet low in Mg (Vit C, S/D) – Should resolve in 4 -8 wk – Re x-ray, and continue diet 1 mo after uroliths gone • Antibiotics according to culture/sensitivity

Feline Uroliths and Urethral Plugs • Medical treatment (obstructed) – Anesthetize (short acting) • ***USE LESS ANESTHESIA IN AZOTEMIC CATS*** – Pass ‘silver needle’ (soft metal, atraumatic) or Tom catheter and back flush – Sew catheter in place for 1 -3 d (? ? )

Feline Uroliths and Urethral Plugs • Surgical treatment (chronic obstructers) – Perineal urethrostomy • New opening for urethra is created proximal to narrowing • Urethral opening looks like a female • E collar till sutures removed

Urolithiasis (Canine) Smaller incidence in dogs than cats Uroliths damage mucosa of urinary tract making it susceptible to infection Uroliths can obstruct urine flow in males • Signs – Dysuria – Hematuria • Dx – Urinalysis • Crystalluria • Hematuria • ↑ bacteria – X-rays (double contrast ? ) – Do stone analysis

Canine Uroliths Urolith Struvite Breed min sch Sex female (80%) Contributing factors alkaline urine Rx acidify urine bacteria→urease→↑p. H minerals (diet) antibiotics Only Hill’s s/d (dissolve) (Mg Ammonium Phos (MAP—triple phosphate) (~50% of all stones) cats ↑Na, ↓protein (ammonia) ↑H 2 O intake (flush stones acidy urine Calcium Oxalate (30 -50% of all stones) cats males min sch Lhasa, Yorkie min pood Shih Tzu diet high in protein hypercalcemia Cushing’s Dis use of cortisone acid urine Sx removal (only Rx) ↓ dietary Ca (milk) ↓ dietary Na Hill’s u/d, w/d, k/d Urates Dalmatians males E bulldogs min schnauzer Shih Tzu York terrier ↑ uric acid from kidneys acid urine Allopurinol (gout in humans) K+ Citrate (↑ urine p. H) Hill’s u/d, ↑ dietary sal

Canine Uroliths Struvite Calcium Oxalate Urate Type of stone cannot be determined by appearance; chemical analysis is required

Urolithiasis (Canine) • Rx – Medical (objective is to dissolve stones) • ↓ mineral intake in diet→↓ minerals in urine • ↑ urine acidity (nor for urates) – Vit C – methionine (Methogel®) • ↑ urine output – Add salt to diet – Furosemide • Antibiotics for bacterial infection – Surgical removal • Some uroliths are not amenable to Medical Rx • However, the cause of uroliths must be dealt with medically (prevention)

Urolithiasis (Canine) What do you see? How many? • Client info – – – Special diet may be required for life-time Table scraps/treats should be limited Long-term antibiotics may be required Uroliths may recur at any time Always provide plenty of fresh water Allow plenty of bathroom time and frequency

Urolithiasis (Canine) What do you see? Flush toward bladder (8 times) Saline flush One in bladder, 2 in urethra

Urolithiasis (Canine) • What do you see?

Urolithiasis (Canine) What do you see?

Urolithiasis (Canine)

Renal Failure • ~20% of CO – Filtered by renal corpuscle – Reabsorbed by kidney tubules – Waste excreted as urine • Renal Failure due to: – ↓ blood flow (hypoperfusion) – Damage to nephron

Acute Renal Failure An abrupt decrease in glomerular filtration → azotemia (↑ N toxins in blood) • Causes – Damage to nephron (damaged nephrons do not regenerate; other nephrons will hypertrophy) Any part of nephron may be damaged (when 1 part of nephron is lost, it is all lost) • Nephrotoxic drugs – – – – Aminoglycosides (gentamicin, streptomycin) Cephalosporins (cephalexin, cephalothin) Sulfanamides (Albon, Di-Trim) Chemotherapeutic agents Antifungal medications Analgesics (acetaminophen) Anesthetics (methoxyflurane [Metafane]) Ethylene glycol (antifreeze) • Infections (nephritis) • Immune-mediated diseases (Glomerulonephritis) – ↓ Renal perfusion • Shock • Hypovolemia/dehydration • Hypotension

Acute Renal Failure • Signs (non-specific) – Kidneys are enlarged and painful on palpation – Signs of azotemia • Anorexia, dehydrated • Vomiting/diarrhea • Weakness – Fever • Dx – Urinalysis—urine sediment/casts; low sp grav (unable to conc urine) – CBC—dehydration (↑PCV), acidosis – Chem panel • ↑ BUN, Creatinine • ↑K+, Phosphorus

Acute Renal Failure • Rx (aim is to restore renal hemodynamics) • Relieve tubular obstruction • Discontinue any toxic drugs – IV fluids (start with normal saline) • Correct dehydration • Correct acid/base (sodium bicarb) and electrolyte imbalance – Diuretics to increase urine output • Client info – Renal function may never be like it was before injury – Px is guarded – Care must be taken to avoid events that may precipitate further damage to kidney • Appropriate diet • Adequate water access

Chronic Renal Failure Common in older pets; cats appear to be more affected than dogs Irreversible and progressive decline in renal function (nephron damage) • Progressive – 1 st function lost: Ability to concentrate urine • PU, PD, nocturia – Loss of ADH response – Other functions lost: Ability to cleanse blood • Azotemia (toxemia) – Begins at ~75% of nephron loss – ↑ BUN, Creatinine • Anemia: erythropoietin secreted by kidneys

Chronic Renal Failure • Signs – Dull, lethargic, weak – Anorexia, wt loss – PU/PD cervical ventroflexion • hypokalemia – Sudden blindness • Dx – Acidosis – Anemia – – ↑ BUN, Creatinine Hyperphosphatemia Hypokalemia Proteinuria

Chronic Renal Failure • Rx – Fluids for dehydration (IV, SQ) – Potassium gluconate, calcium carbonate for electrolyte imbalances – Sodium bicarb for p. H adjustment – Diuretics (Furosemide) – Hormones • Epoetin – Vit B supplements • Client info – – – CRF is progressive and irreversible Rx is aimed at slowing its progress SQ fluids at home are required to maintain hydration Warm foods to improve palatability Quality of life will decrease; euthanasia may have to be considered

Urinary Incontinence Loss of voluntary control of micturition • Causes – Neurogenic—loss of normal neural function causing a paralyzed bladder – Ectopic ureters – Patient urachus – Endocrine imbalance (after spay)

Urinary Incontinence • Signs – Urine leakage when pet is sleeping or exercising – Perianal area of pet is aslways wet – Concurrent urinary tract infection • Dx – Urinalysis – X-rays/cystography – Chem panel to r/o PU from endocrine disease

Urinary Incontinence • Rx (based on specific cause) – Surgical correction – Endocrine deficiency in spayed female • Diethylstilbestrol (PO or inj) – Phenylpropanolamine (for loss of sphincter tone) • Client info – Doses will have to be adjusted for individual animals – Paralytic bladder incontinence may require manual expression or catheterization several times a day