“No pressure, no diamonds.” -Mary Case ADVERSITY “No pressure, no diamonds.” -Mary Case

DISEASES OF THE URINARY SYSTEM Cystitis Cystic calculi Urinary obstruction ARF & CRF Incontinence

BLOOD FLOW THROUGH THE KIDNEYS Renal arteriole > glomerulus > bowman’s capsule > proximal convoluted tubule > loop of Henle > ELIMINATED: distal convoluted tubule > collecting ducts > renal pelvis > urine

COMPONENTS OF THE URINARY SYSTEM and ITS FUNCTIONS Functions of the kidneys Excretion: produce urine Maintain homeostasis Blood filtration, reabsorption, secretion Fluid balance regulation Acid-base balance regulation Hormone production

DISEASES OF THE URINARY SYSTEM URINARY SYSTEM IS NORMALLY STERILE AND RESISTANT TO BACTERIAL INFECTION Voiding of urine Urethral/ureteral peristalsis Glycosaminoglycans in the surface mucosal layer pH

RECOGNIZING URINARY SYSTEM DISORDERS About 4 million cats a year are destroyed for “elimination problems”.

DIAGNOSING URINARY SYSTEM DISORDERS DIAGNOSTIC TESTS THAT MAY BE DONE IN PATIENTS WITH URINARY DISEASE URINALYSIS (dipstick and sediment exam) RADIOGRAPHS

DISEASES OF THE URINARY SYSTEM Cystitis Cystic calculi Urinary obstruction ARF & CRF Incontinence

Feline Idiopathic (Interstitial) Cystitis aka FUS/ FLUTD FACTS: -Occurs in cats 2-6 yrs old -Occurrence in males > females -cause unknown, multi-factorial -not caused by bacterial infection -recurrence is likely

Feline Idiopathic (Interstitial) Cystitis Clinical Signs pollakiuria Hematuria Dysuria Periuria (sinks, tubs, carpet, etc.)

Feline Idiopathic (Interstitial) Cystitis Diagnostics Urinalysis/culture to r/o bacteria as cause Only 1%-3% of all feline cystitis is caused by bacteria Radiographs to r/o calculi; contrast studies may show thickened bladder wall

Feline Idiopathic (Interstitial) Cystitis Treatment Avoid unnecessary antibiotics Change diet from dry to moist Or salt food to ↑ water intake Reduce stress from other cats, kids, etc Provide hiding places Pheromonotherapy Behavior modification drugs (may also have pain reducing effects Amitryptilline (tri-cyclic antidepressant) Clomipramine Glycosaminoglycan replacement Cosequin for cats Adequan

Feline Idiopathic (Interstitial) Cystitis Client info Disease is self-limiting As many as 85% of cats will have resolution of clinical signs in 7-10 days May be recurring problem No definitive cure Reduce stress

Canine Bacterial Cystitis Cause: Ascending bacteria up the urethra Signs ↑ frequency of urination Hematuria Dysuria Cloudy urine, abnormal color Frequent licking of vaginal/urethral area

Canine Bacterial Cystitis Diagnostics Urinalysis: ↑WBC’s, bacteria Common bacteria: E.coli, Proteus spp. Urine culture/sensitivity Collect by cystocentesis or mid- stream collection

Canine Bacterial Cystitis Treatment Antibiotics according to sensitivity Treat acute infections x 10-14 d Subsequent infections x 4-6 w Avoid trauma to urinary tract during surgery Patients needing indwelling catheters should have a closed system

Closed Urinary Catheter System

Canine Bacterial Cystitis 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

DISEASES OF THE URINARY SYSTEM Cystitis Cystic calculi Urinary obstruction ARF & CRF Incontinence

Feline Uroliths and Urethral Plugs “Plugged” or “Blocked” male cats are commonly seen in small animal practice and can be fatal if not relieved

Feline Uroliths & Urethral Plugs The two most common causes of urethral blockage are uroliths and urethral plugs UROLITHS: composed of minerals and a small amount of matrix URETHRAL PLUGS: composed of small amount of minerals and large amount of matrix

Feline Uroliths and Urethral Plugs Signs Hematuria Dysuria Periuria Anorexia, vomiting Collapse, death Non-specific signs: Hiding Crying while urinating Frequent trips to the litterbox

Feline Uroliths and Urethral Plugs 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 (cystine) and require double contrast Pneumocystogram

Feline Uroliths and Urethral Plugs Uroliths damage bladder, making it more susceptible to bacterial infection, hematuria Uroliths can cause blockage of the urethra of males Bladder will fill with urine Kidneys will stop working Blood/body will become toxic (azotemic)

Feline Uroliths and Urethral plugs

Feline Uroliths and Urethral Plugs Dx Palpation of bladder Obstructed bladders are full and tight Radiographs may show uroliths on routine films Ultrasonography can locate position of urolith Urolith analysis is necessary to determine its constituents EKG: atrial standstill, bradycardia, hyperkalemia

Feline Uroliths and Urethral Plugs Double-contrast cystogram with stones Normal double-contrast cystogram pneumocystogram

Ultrasound of bladder stone

Feline Uroliths and Urethral Plugs Treatment Medical treatment (chronic, non-obstructed) Dissolve struvite uroliths (most common- ~60%) by acidifying urine and feeding diet low in Mg (Hill’s S/D, c/d, others) Should resolve in 4-8 wk Re-radiograph, and continue diet 1 mo after uroliths gone Cystotomy to remove stones Antibiotics according to culture/sensitivity

Feline Uroliths and Urethral Plugs

Feline Uroliths and Urethral Plugs Medical treatment (obstructed) This is a medical emergency Anesthetize (short acting) *USE LESS ANESTHESIA IN AZOTEMIC CATS* Pass Tom cat catheter and back flush Sew catheter in place for 1-3 d, using a closed system

Feline Uroliths and Urethral Plugs

Closed Urinary Catheter System

Feline Uroliths and Urethral Plugs Surgical treatment (chronic obstructers) Perineal urethrostomy (PU) New opening for urethra is created proximal to narrowing Urethral opening looks similar to female anatomy *Goal of surgery is to decrease the likelihood of life-threatening obstruction*

Feline Uroliths and Urethral Plugs: Perineal Urethrostomy

Feline Uroliths and Urethral Plugs: Perineal Urethrostomy

Canine Urolithiasis Os Penis

Canine Urolithiasis Uroliths damage mucosa of urinary tract making it susceptible to infection Uroliths can obstruct urine flow in males Clinical Signs pollakiuria Dysuria Hematuria

Canine Urolithiasis Dx Urinalysis Radiographs Crystalluria Hematuria ↑ bacteria Radiographs

Canine Urolithiasis

Canine Uroliths Urolith Breed Sex Contributing factors Rx Struvite min sch female (80%) alkaline urine acidify urine (Mg Ammonium Phos) cats bacteria→urease→↑pH antibiotics minerals (diet) Only Hill’s s/d (dissolve) ↓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 all stones) Lhasa, Yorkie Cushing’s Dis min poodle 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, Yorkshire terrier

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

Urolithiasis (Canine) Treatment Medical (dissolve stones if Struvite) diet Acidify urine Urinary acidifiers (methionine, Methogel) ↑ urine output Add salt to diet, increase water intake Antibiotics for bacterial infection Surgical removal ( Ca Oxalate) Some uroliths are not amenable to Medical Rx However, the cause of uroliths must be dealt with medically (prevention) STONE ANALYSIS IS VITAL FOR APPROPRIATE TREATMENT

Canine Urolithiasis: Cystotomy for stone removal

Canine Urolithiasis What do you see?

Canine Urolithiasis 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

EDUCATION “It is possible to store the mind with a million facts and still be entirely uneducated.” - Alec Bourne

DISEASES OF THE URINARY SYSTEM Cystitis Cystic calculi Urinary obstruction ARF & CRF Incontinence

Renal Failure ~20% of Cardiac output 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 and glomerular filtration declines resulting in azotemia

AZOTEMIA Pre-renal Renal Post-renal dehydration Primary kidney disorders Post-renal Urinary tract obstruction

Acute Renal Failure Three distinct phases: Induction: the time from the initial insult until decreased renal function is apparent (hours to days) Maintenance: the time period during which renal tubular damage occurs (weeks to months) Recovery: the time during which renal function improves, existing nephrons hypertrophy and compensate for those damaged, and tubular repair occurs (when possible)

Stages of Kidney disease Loss of Renal Reserve - Early signs of PU/PD PU= polyuria (increased urination) PD= polydipsia (increased drinking) Renal Insufficiency - Early warning signs, such as increased thirst, may begin to appear Renal Failure (Azotemia) - Kidneys cannot eliminate waste efficiently, causing signs of illness Advanced Kidney Failure (Uremia) - Severe signs of illness appear; eventually, collapse and death result

Acute Renal Failure Causes Damage to nephron Nephrotoxic drugs An abrupt decrease in glomerular filtration →azotemia Causes Damage to nephron Nephrotoxic drugs Aminoglycosides (gentamicin, streptomycin) Chemotherapeutic agents Antifungal medications Analgesics (acetaminophen) Anesthetics (methoxyflurane [Metafane]) Ethylene glycol (antifreeze)

Acute Renal Failure Causes: Infections (pyelonephritis) Immune-mediated diseases (Glomerulonephritis) Metabolic: Hypercalcemia ↓ 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

Acute Renal Failure Dx Urinalysis urine sediment - casts low sp gravity (unable to concentrate urine) CBC dehydration (↑PCV) acidosis Chem panel ↑ BUN, Creatinine ↑K+, Phosphorus

Tx (aim is to restore renal hemodynamics) Acute Renal Failure Tx (aim is to restore renal hemodynamics) Relieve tubular obstruction Discontinue any toxic drugs IV fluids Correct dehydration Correct acid/base imbalance

Acute Renal Failure Client info Renal function may never be like it was before injury Prognosis is guarded especially with older pets 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) Dogs > 8 yrs Cats > 10 yrs The normal function of ADH (antidiuretic hormone: released from the brain) on the kidneys is to control the amount of water reabsorbed by kidney nephrons. ADH acts in the distal portion of the renal tubule (Distal Convoluted Tubule) as well as on the collecting duct and causes the retention of water, but not solute. Hence, ADH activity effectively dilutes the blood (decreasing the concentrations of solutes such as sodium). ADH is secreted to prevent water loss in the kidneys

Chronic Renal Failure 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 Dull, lethargic, weak Anorexia, wt loss PU/PD, cervical ventroflexion hypokalemia protein matrix (Tamm-Horsfall mucoprotein) that makes up the hyaline cast (hyaline with fat) particulate material from degenerating cells is present within the cast matrix (hyaline to finely granular cast).

Chronic Renal Failure Dx Acidosis Anemia Proteinuria ↑ BUN, Creatinine increased phosphorus Hypokalemia Proteinuria

Chronic Renal Failure Tx Fluids for dehydration (IV, SQ) Potassium gluconate, calcium carbonate for electrolyte imbalances Phosphorous binders: Aluminum hydroxide Sodium bicarbonate for pH adjustment Hormones Epoetin Vit B supplements

Chronic Renal Failure 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

Azotemia: Bun and Creatine ARF (large size) CRF (small size) PCV Inc. Dec. Azotemia: Bun and Creatine Phosphorous Potassium Other Acidosis, proteinuria

DISEASES OF THE URINARY SYSTEM Cystitis Cystic calculi Urinary obstruction ARF & CRF Incontinence

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

Urinary Incontinence Signs Dx Urine leakage when pet is sleeping or exercising Perianal area of pet is always 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 (PROIN: 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 DES: Estrogen

References Alleice Summers, Common Diseases of Companion Animals http://veterinarymedicine.dvm360.com/vetmed/article/article Detail.jsp?id=738082 http://ahdc.vet.cornell.edu/clinpath/modules/index.htm http://www.vetmed.wsu.edu/ClientED/anatomy/dog_ug.aspx http://veterinarynews.dvm360.com/dvm/article/articleDetail.j sp?id=533210 http://www.walthamusa.com/articles/c-kidney.pdf