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

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 B/C OF: Voiding of urine Urethral/ureteral peristalsis Glycosaminoglycans in the surface mucosal layer pH (6.0 – 6.3) Glycosaminoglycans are large protein/sugar complexes that have anti-inflammatory properties; can be given as supplements

URINARY SYSTEM DISORDERS Clients abandon pets or want pet put down because of inappropriate elimination About 4 million cats a year are destroyed or abandoned for “elimination problems”.

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

Feline Idiopathic (Interstitial) Cystitis aka FUS/ FLUTD Feline Urologic Syndrome or Feline Lower Urinary Tract Disease Most common cause of UTI in cats; rarely associated with bacteria FACTS: Occurs in cats almost any age Occurrence in males > females cause unknown, multi-factorial, virus(?) not caused by bacterial infection recurrence is likely

Feline Idiopathic (Interstitial) Cystitis Clinical Signs pollakiuria Hematuria Dysuria Periuria (sinks, tubs, carpet, etc.) Pollakiuria – passing small amounts of urine very frequently Polyuria – passing large amounts of dilute urine; usually associated with polydipsia

Feline Idiopathic (Interstitial) Cystitis Diagnostics Urinalysis/culture to rule out bacteria as cause Only 1%-3% of all feline cystitis is caused by bacteria Radiographs to rule out calculi

Feline Idiopathic (Interstitial) Cystitis Treatment Avoid unnecessary antibiotics Change diet from dry to moist or add water to dry food 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 We underuse GAGs in cats

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, but diet change is the most effective (Hill’s c/d Stress) Reduce stress Any treatment instituted will look like it works bc it clears up on its own Cats need to have hiding spots and “safe” places; and access to litter boxes in safe space

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 culture/sensitivity results 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 Can cut urethra during neuter; myths about tying off ureters during OHE; stabbing full bladder through skin incision when entering abomen

Closed Urinary Catheter System

Canine Bacterial Cystitis Client info Many uncomplicated UTI’s resolve without treatment Give antibiotics as directed for the time prescribed Prostate may be source of recurring infections in male dogs Urine cultures should be repeated during treatment to assess effect Urine cultures are expensive

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 predominantly of minerals URETHRAL PLUGS: composed predominantly of matrix (mucoprotein, rbcs, wbcs, epithelial cells, etc.)

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 Anorexia/vomiting due to uremia and azotemia

Feline Uroliths and Urethral Plugs Uroliths can be 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 special imaging techniques to visualize Struvites – MAP or triple phosphate crystals 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 Patient will become azotemic

Feline Uroliths and Urethral plugs

Feline Uroliths and Urethral Plugs Diagnosis Palpation of bladder Obstructed bladders are full and tight Radiographs may show uroliths Ultrasonography Urolith analysis is necessary to determine its constituents EKG: atrial standstill, bradycardia, due to hyperkalemia Bladder will feel like a huge rock

Feline Uroliths and Urethral Plugs Treatment Medical treatment (non-obstructed) Dissolve struvite uroliths by acidifying urine and feeding diet low in Mg (Hill’s S/D, c/d) 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 Struvites are made of Mg

Feline Uroliths and Urethral Plugs

Feline Uroliths and Urethral Plugs Medical treatment (obstructed) This is a medical emergency Anesthetize *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 What is azotemia?

Feline Uroliths and Urethral Plugs

Closed Urinary Catheter System

Feline Uroliths and Urethral Plugs Surgical treatment (chronic obstructors) 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

https://youtu.be/2KcuW- trvPI Feline Perineal Urethrostomy https://youtu.be/RO5XD t3vg5Q Dr. Martinez

CANINE UROLITHIASIS

Canine Urolithiasis Uroliths damage mucosa of urinary tract making it susceptible to infection Uroliths can obstruct urine flow in males

Canine Urolithiasis The distal portion of the canine urethra is contained in the narrow canal of the os penis. This can be a common location for urethral stones to become lodged.

Canine Urolithiasis Clinical Signs pollakiuria Dysuria Hematuria Dx Urinalysis Crystalluria ↑ bacteria Radiographs

Canine Urolithiasis

Canine Uroliths Struvite min sch female alkaline urine acidify urine Urolith Breed Sex Contributing factors Rx Struvite min sch female alkaline urine acidify urine (Mg Ammonium Phos) cats bacteria→urease→↑pH antibiotics minerals (diet) Hill’s s/d (dissolve) ↓protein (ammonia) ↑H2O intake (flush stones) Calcium Oxalate cats males dietary protein Sx removal (30-50% of min sch hypercalcemia ↓ dietary Ca all stones) Lhasa, Yorkie min poodle Hill’s u/d, w/d, k/d Shih Tzu acid urine Urates Dalmatians males ↑ uric acid from kidneys Allopurinol Eng bulldogs acid urine 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 management - dissolve stones if Struvite Prescription diets Acidify urine Urinary acidifiers ( Methogel (methionine)) ↑ urine output increase water intake Antibiotics for bacterial infection Surgical removal ( Ca Oxalate) Some uroliths are not amenable to Medical Rx Prevention is key STONE ANALYSIS IS VITAL FOR APPROPRIATE TREATMENT

Canine Urolithiasis: Cystotomy for stone removal

Canine Urolithiasis What do you see? Don’t miss the stones lined up in the urethra!

Canine Urolithiasis Client info Special diet may be required for life 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 Renal Insufficiency - Early warning signs, such as PU/PD 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 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)

Infections (pyelonephritis) Acute Renal Failure More causes: Infections (pyelonephritis) Immune-mediated diseases (Glomerulonephritis) ↓ Renal perfusion Shock Hypovolemia/dehydration Hypotension

Kidneys are enlarged and painful on palpation Signs of azotemia 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 Diagnosis Urinalysis urine sediment - casts low sp. gravity (unable to concentrate urine) CBC dehydration (↑PCV) Chem panel ↑ BUN, Creatinine Hyaline casts – clear, made of muco-protein, can be seen occasionally in healthy patients Cellular – associated with acute disease, necrosis, infarction, ischemia Granular casts – can be seen in healthy patient; can come from degeneration of cellular casts; not always indicative of disease Fatty casts – associated with tubular degeneration Waxy casts – clear and rectangular shaped (squared-off ends); associated with chronic kidney dz and always of pathological significance

Tx (aim is to restore renal hemodynamics) Acute Renal Failure Tx (aim is to restore renal hemodynamics) Relieve any urinary 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) 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 1st function lost: Ability to concentrate urine Progressive 1st function lost: Ability to concentrate urine PU, PD, nocturia Loss of ADH response Other functions lost: Ability to filter blood Azotemia 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 Hypokalemia causes generalized muscle weakness; K+ is also lost from excessive vomiting

Chronic Renal Failure Diagnosis Look for abnormal blood work associated with kidney function Anemia ↑ BUN, Creatinine Proteinuria

Chronic Renal Failure Treatment Fluids for dehydration(IV, SQ) Correct electrolyte imbalances Hormones Epoetin Start with normal saline, 5% dextrose in water, LRS; add electrolytes to bag as needed

Client info Chronic Renal Failure CRF is progressive and irreversible treatment is aimed at slowing its progress SQ fluids at home are required to maintain hydration 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 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) Patent urachus- tube that carried fetal urine to umbilicus did not close; causes animal to dribble urine from naval area

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 Treatment (based on specific cause) Client info Surgical correction Endocrine deficiency in spayed female Diethylstilbestrol 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