Diseases of Urinary System

Urinary System Anatomy/Location Function 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 pH

Feline Cystitis Signs Dx Frequent urinations (sm vol) Hematuria 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 Client info 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 cat 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 ↑ bacteria X-rays (double contrast ?) Do stone analysis

Canine Uroliths Urolith Breed Sex Contributing factors Rx Struvite min sch female (80%) alkaline urine acidify urine (Mg Ammonium Phos (MAP—triple phosphate) (~50% of all stones) cats bacteria→urease→↑pH antibiotics minerals (diet) Only Hill’s s/d (dissolve) ↑Na, ↓protein (ammonia) ↑H2O intake (flush stones acidy urine Calcium Oxalate cats males diet high in protein Sx removal (only Rx) (30-50% of min sch hypercalcemia ↓ dietary Ca (milk) all stones) Lhasa, Yorkie Cushing’s Dis ↓ dietary Na min pood use of cortisone Hill’s u/d, w/d, k/d Shih Tzu acid urine Urates Dalmatians males ↑ uric acid from kidneys Allopurinol E bulldogs acid urine (gout in humans) min schnauzer K+ Citrate (↑ urine pH) Shih Tzu Hill’s u/d, ↑ dietary salt York terrier

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 Renal Failure due to: 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 Causes 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) Dx 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 Progressive Common in older pets; cats appear to be more affected than dogs Irreversible and progressive decline in renal function (nephron damage) Progressive 1st 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 Dx 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 Client info Fluids for dehydration (IV, SQ) Potassium gluconate, calcium carbonate for electrolyte imbalances Sodium bicarb for pH 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 Causes 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 Dx 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) Client info 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