A Case of Cystic and Urethral Calculi in a Dog Buddy’s Bad Luck: A Case of Cystic and Urethral Calculi in a Dog Olivia Miller AUCVM Class of 2015

History 10 year old male, castrated Miniature Schnauzer. Presented on 11/18/2014. ~5 days of dribbling urine and stranguria. Cystic and urethral calculi. Current medications and treatments: Amoxicillin, enrofloxacin, meloxicam. IV fluid support, intermittent urinary catheterization to relieve obstruction. On a diet of canine s/d. Previous cystotomy in 2011.

Presentation: HR: 124 bpm RR: 32 brpm T: 101.4 F MM: pink, slightly tacky CRT <2s BCS 3/9 Stiff, slow gait. Significant bruising, edema of the inguinal and scrotal regions. *History and clinical signs- possible urethral tear.

Initial Plan: CBC/Serum Chemistry Thoracic radiographs Abdominal radiographs Contrast Urethrogram

CBC/Serum Chemistry: CBC: unremarkable Chemistry: Mild decreases in albumin, calcium. Mild increases in ALT, AST, ALP, bilirubin, BUN Thoracic Radiographs:

Abdominal Radiographs

Urethrogram Want smooth contrast column. Sterile procedure. Water soluble iodinated contrast solution.

Problem List: Cystic calculi Urethral calculi Urethral tear Soft tissue damage

New Plan: Off to Surgery! Cystotomy Urethrotomy +/- Urethrostomy Collect samples for stone analysis, culture/sensitivity.

Canine Urethrotomy Temporary incision. In comparison to urethrostomy- permanent opening created. More common in males. Performed by making a sharp incision on midline and gently extracting calculi using instruments and saline lavage to push calculi into the incision site. Primary wound closure or secondary wound closure. Primary- with small monofilament suture, more risk of stricture formation Secondary- takes longer to heal, less risk of strictures

Canine Cystotomy Incision in ventral side of the bladder. Note location of trigone, apex, and ligaments. Place stay sutures. -placed at 9, 12, and 3 o’clock positions. Aspirate urine- suction or syringe. Evaluate interior of bladder. Calculi removal. Excise a small piece of the bladder wall along the incision to submit for culture/histopathology. Single or double layer closure. Single or double layer closure, inverting or appositional patterns.

Stage 1: Urethrotomy Locating the urethra. Subcutaneous stones.

Stage 2: Stone removal Using the gallbladder stone spoon. ~Half of the calculi we removed.

Stages 3 & 4: Damage Assessment and Cystotomy Locating the urethral tear. Beginning the cystotomy.

Stages 5 & 6: More stone removal! Removing bladder stones. Passing a urinary catheter.

Stages 7 & 8: Passage of a urinary catheter and closure Checking for any obstructions. Placing a pexy.

Post-Op Care: IV fluids: LRS at 15 mL/hr. Monitor urinary catheter/urine production. Hydromorphone 0.05 mg/kg IV q 4-6 hours. Transition to oral Tramadol 4 mg/kg PO q 6-8 hours. Meloxicam 0.1 mg/kg PO with food q 24 hours. Warm pack incision/surrounding soft tissues. Royal Canin Urinary S/O. Monitor incisions. Daily bandage changes and lavage of surgical site.

Comparing Radiographs:

Canine Urinary Calculi What are they? Organized concretions of mineral and organic matrix. Two predisposing factors: supersaturation of the urine with minerals and changes in urine pH. Common Types: Magnesium ammonium phosphate (struvite), calcium oxalate, and urate. Less Common: Xanthine, cysteine, calcium phosphate and silica. Urate and cysteine stones are radiolucent!

Struvite Calculi The most common in dogs. Composed of magnesium, ammonium, and phosphate. Clinical Signs: Alkaline urine (pH > 6.5) Urinary tract infection. Large, radiodense calculi on radiographs. Causes: Urinary tract infection with urease producing bacteria (often Staphylococcus or Proteus spp.) Sterile causes: Hereditary, dietary

Treatment/Prevention Surgical removal Culture and susceptibility of urine/urinary calculi. Appropriate antimicrobial therapy for 14 days, then re-culture urine. Medical management: Low protein diet (ex: Hill’s S/D or Royal Canin Urinary S/O) Prevention: Keep urinary tract infection free. Dietary management with acidifying diet. Urine culture every 3 months, repeat radiographs every 6 months.

Back to Buddy: Culture and susceptibility results: Heavy growth of Staphylococcus intermedius group Susceptible to amoxicillin/clavulanic acid! Placed on 22 mg/kg every 8 hours for 14 days. Stone analysis results: Magnesium ammonium phosphate (struvite) and calcium phosphate calculi. Calcium phosphate calculi- occur most often with struvites, more common in females than males, radiodense. Treatment- surgical removal and treatment of underlying conditions. Prevention- similar to struvite prevention, increase water intake, maintain urine pH of 6- 6.5.

Summary of Hospitalization Length of Stay: 11/18/14- 12/09/14 Treatments: Daily bandage changes through 12/02/14 Tramadol and meloxicam. Warm compress. Amoxicillin-clavulanic acid. Dietary management with Royal Canin Urinary S/O Removal of urinary catheter on 12/05/14. 12/08/14: Repeat radiographs revealed the “jelly bean shaped” calculus was still present. Successfully removed later that afternoon! 12/09/14: Discharged

Update on Buddy Buddy is doing very well at home! Playful and eating well! Though still urinating through the urethrotomy site…

Take Home Points Things don’t always go according to plan. Take post-op radiographs!

References Ettinger, Stephen J.; Feldman, Edward C. Textbook of Veterinary Internal Medicine. 7th Edition. St. Louis, MO: Saunders, 2010. Print. Smeak, Daniel. Urethrotomy and Urethrostomy in a Dog. Clinical Techniques in Small Animal Practice, Vol 15, No 1. 2000. pp 25-34. Thrall, Donald E. Textbook of Veterinary Diagnostic Radiology. 5th Edition. St. Louis, MO: Saunders, 2007. Print. Tobias, Karen M., and Spencer A. Johnston. Veterinary Surgery. Vol. 1. St. Louis, MO: Saunders, 2011. Print.

Acknowledgements Jarrod My Family & Friends Dr. Kry Dr. Tillson My Omega Tau Sigma Family Soft Tissue Surgery Rotation Ophthalmology Rotation Class of 2015

Questions?

Chemistry Test Result Reference Range Albumin 2.0 g/dL 3 – 4.3 g/dL ALT 196 U/L 13 – 151 U/L AST 61 U/L 18 – 55 U/L ALK PHOS 368 U/L 14 – 152 U/L Total Bilirubin 0.21 mg/dL 0 – 0.2 mg/dL BUN 38.9 mg/dL 9 – 34 mg/dL Calcium 9.0 mg/dL 9.6 – 12 mg/dL