Food Animal Urology M. S. Gill, D.V.M., M.S.

Food Animal Urology P.E. & evaluation of the urinary system Urolithiasis Bacterial diseases Toxic plants Parasitic diseases Miscellaneous conditions Congenital conditions Neoplasia

Physical examination External structures Urethral area in males Vaginal exam Cystoscopy Radiography Micturition – normal behavior Urine collection Normal frequency / quantity Palpation Urine characteristics Kidney function evaluation Kidney biopsy

External structures Purulent exudate in vagina or prepuce Presence of crystals Hemorrhages Neoplasia Vulva Penis

Urethral area in males Look for obvious enlargements Hematomas Ruptured urethra – “water belly”

Vaginal exam Use a vaginal speculum in cow, ewe, doe, sow/gilt to examine urethral orifice

Cystoscopy Fiber optic endoscope to examine inside of bladder Epidural Empty urine Inject 500cc of air

Radiography Most useful in small or young ruminants IVP or contrast study

Micturition – normal behavior Cows usually urinate right after standing Arched back, raised tail, straddled legs May urinate when eating, walking or lying down Bulls Arched back, raised tail May dribble urine or urinate with repeated short pulsations *Abnormal posture may indicate problems

Urine collection Cows Bulls/steers Ewes stimulate vulva or catheterize Bulls/steers Preputial massage Catheterization too difficult Ewes Hold off nose Lasix® may be used IV but lowers S.G. of sample

Normal frequency / quantity Varies with water consumption, season, milk production, age and use Species ml/kg/day # times/day Sheep/goat 10-40 1-3/day Cattle 17-45 5-6/day Swine 5-30 2-3/day

Palpation Rectal palpation of kidneys Left kidney – 3rd-5th lumbar vertebra, mobile, usually on right side, can palpate rectally Right kidney – 12th thoracic – 3rd lumbar vertebra, right side, not mobile, not palpable per rectum Lobulated in bovine, smooth in sheep, goats, pigs Feel for obvious enlargement, change in consistency, loss of lobulation, decrease in size of kidneys

Palpation Rectal palpation of ureters in cattle Normally the size of straws Palpation of urinary bladder Rectally in cattle Abdominal palpation in small ruminants/calves Palpation of urethra Rectally or in perineal area

Urine characteristics Viscosity Normally watery Color Straw to amber colored normal Light yellow vs. dark No hemoglobin, myoglobin, blood Transparency Clear, transparent Turbid or cloudy abnormal Odor Ketones, strong ammonia abnormal Urinalysis

Urine characteristics Urinalysis Specific gravity – 1.020 – 1.040, as low as 1.007 in dairy cows, water deprivation test used to access concentrating ability pH – 7.0-8.0, aciduria with ketosis, lactic acidosis, paradoxical Protein Ketones Glucose (stress, IV glucose, steroids, xylazine, *enterotoxemia*) Blood, hemoglobin, myoglobin Bacteria Crystals

Red Urine Hematuria Hemoglobinuria Myoglobinuria Pyelonephritis, cystitis, urolithiasis, enzootic hematuria, embolic nephritis Hemoglobinuria Leptospirosis, bacillary hemoglobinuria, copper toxicity, post-parturient hemoglobinuria, cold water intoxication Myoglobinuria Cassia toxicity, capture myopathy * Anaplasmosis = normal urine

Kidney function BUN – 10-30 mg/dl Creatinine - < 2 mg/dl Creatinine may increase more quickly than BUN due to the ruminant’s ability to recycle urea through the rumen

Kidney biopsy Can be very helpful for diagnosis after other diagnostic tests have been exhausted

Obstructive Urolithiasis in Food Animals

Predisposing factors increased urine concentration urine stasis increased urine pH increased mineral excretion decreased urinary colloids desquamated epithelial cells UT infections increased urinary mucoproteins

Factors favoring development of obstruction long, convoluted urethra - sigmoid flexures urethral process in small ruminants early castration exogenous estrogens - growth promoting implants

Anatomy Common sites for obstruction: urethral process vermiform appendage “pizzle” distal sigmoid flexure

Calculus composition phosphate calculi * silicate oxalate magnesium ammonium phosphate = struvite calcium phosphate = apatite silicate oxalate calcium carbonate

Phosphate calculi

Calcium carbonate calculi

Clinical findings stranguria - (often mistaken for constipation) anorexia, mild bloat, lethargy treading, stretching, kicking @ abdomen vocalization (especially goats) palpable bladder distention abdominal palpation in small ruminants rectal palpation in large ruminants azotemia

Clinical findings con’t. blood or crystals on preputial hairs

Sequelae to untreated obstruction ruptured urethra with accumulation of SQ urine ventrally ruptured bladder with development of uroperitoneum

Sequelae to untreated obstruction subcutaneous urine accumulation leads to necrosis and skin slough if not drained uroperitoneum may not cause much damage to peritoneal cavity

Medical Treatment phenothiazine tranquilizers IV fluids - 0.9% NaCl slow drainage of uroperitoneum via trochar in cases of ruptured bladder paramedian skin incisions to drain urine in cases of ruptured urethra antibiotics urinary acidifiers

Surgical Management amputation of the urethral process (small ruminants) urethral catheterization / retrograde flushing perineal urethrostomy tube cystotomy ischial urethrostomy cystostomy

Amputation of the urethral process most common location for calculi to lodge (small ruminants) exteriorize penis with animal sitting on rump - tranquilization &/or epidural may help amputate process close to attachment to glans

Amputation of the urethral process if calculi lodged in process recurrence likely use medical therapy concurrently

Urethral process amputation in 14/16 cases (88%) which had urethral process amputation, obstruction was either not relieved or was relieved and recurred within 36 hrs. 10/14 goats (71%) successfully treated with urethral process amputation re-obstructed within a year (6 of these 10 re-obstructed within 3 days of surgery)

Urethral catheterization / retrograde flushing difficult to catheterize bladder due to presence of suburethral diverticulum catheterization may result in urethritis, urethral rupture, urethral stricture

Perineal urethrostomy salvage procedure low approach preferred to prevent urine scald post-op stricture formation common

Perineal urethrostomy urethral obstruction recurrence rate of 45% within 8 months of surgery and a 1-year survival rate of 17% reported 7 of 9 small ruminants (78%) developed stricture of within 8 months of surgery

Cystotomy 7 of 8 cases (88%) in which cystotomy was performed for urethral obstruction were healthy at the time of follow-up cystotomy allows for removal of multiple calculi in the bladder as well as bidirectional flushing of the urethra cystotomy had a long term survival of 88% as compared to a 55% survival with perineal urethrostomy

Tube cystostomy Useful in small ruminants and calves Allows removal of calculi from bladder and ante- and retrograde flushing of the urethra

Tube cystostomy Foley catheter remains in place until animal can urinate through urethra successfully for several days with the catheter occluded Normal urination occurs around 10-14 days post-op

Tube cystostomy Tube cystostomy was successful in relieving obstruction in 12 of 15 small ruminants (13 goats, 2 sheep)

Tube cystostomy

Ischial urethrostomy

Urinary bladder marsupialization (cystostomy) to provide long term resolution of urinary obstruction in small ruminants not intended for slaughter 18/19 goats in one study survived the surgery and at follow up, 15 of 17 owners were satisfied with the procedure

Contagious Bovine Pyelonephritis Corynebacterium renale Ascending urinary tract infection in cows Clinical findings Hematuria, pollakiuria, pyuria Thickened bladder wall, enlarged ureters, painful kidney

Contagious Bovine Pyelonephritis BUN, creatinine remain normal until late stage UA – RBCs, WBCs, protein, bacteria Treatment Penicillin, high doses for at least 2 weeks Nephrectomy if only one kidney involved Prognosis poor

Ulcerative posthitis “pizzle rot” C. renale Common in wethers on high protein diets - increases urea content of urine Bacteria hydrolyze urea into ammonia which is cytotoxic

Ulcerative posthitis Reduce legumes in diet Topical treatment Penicillin

Corynebacterium suis “Thin sow syndrome” Cystitis, pyelonephritis Venereal transmission from boar Treatment - penicillin

Leptospirosis Multisystemic disease affecting all domestic animals Organisms shed in urine, infect mucous membranes Chronic infection causes diffuse interstitial nephritis Tetracycline Bacterins

Embolic nephritis Secondary to bacteremia or septicemia Bacteria lodge in small vessels and create infarcts in the kidney No clinical signs until lesions are large enough to impair renal function May be incidental finding on necropsy Treat primary disease with Ab’s

Amaranthus retroflexus Red root pigweed Perirenal edema and kidney pathology Toxic principle unknown Death due to hyperkalemia No specific treatment Avoid exposure

Oak poisoning Quercus spp. Both oak buds and acorns are toxic Toxic principle = tannin or gallotanin Hepatotoxic, nephrotoxic, cause precipitation of proteins gastroenteritis, hemorrhages, edema, renal lesions (nephrosis)

Bracken fern Enzootic hematuria Transitional cell carcinoma of the bladder

Renal amyloidosis Sequella of chronic suppurative process Deposition of amyloid in a variety of organs with loss of function Chronic antigenic stimulation Hypoproteinemia, proteinuria, edema, diarrhea (resembles Johne’s disease) No treatment

Urachal vestiges Persistent or infected urachus Signs include dysuria, pollakiuria, stranguria Treatment by surgical removal

Congenital diseases Polycystic kidneys Bilateral renal hypoplasia Hypospadias Ectopic ureter

Neoplasia External genitalia Kidney Bladder Fibropapilloma Squamous cell carcinoma Kidney Lymphosarcoma Adenoma Nephroblastoma Bladder Transitional cell carcinoma