544 JAVMA • Vol 248 • No. 5 • March 1, 2016 Small Animals A 32-month-old spayed female Devon Rex (cat 1) was evaluated because of a history of urinary in- continence that had persisted since the cat had been adopted at 18 months of age. The incontinence was rated as 4 on a scale from 1 to 10, according to a previ- ously published continence scoring system 1 (1 = com- pletely incontinent, leakage constantly, never achiev- ing a full bladder to allow posturing to urinate; 5 = moderately incontinent, leakage mainly when lying down or when bladder is full, some leakage between urinations, may leak immediately before or after urina- Use of a percutaneously controlled hydraulic occluder for treatment of refractory urinary incontinence in three female cats Kendall E. Wilson DVM Allyson C. Berent DVM Chick W. Weisse VMD From the Department of Interventional Radiology and Endoscopy, The Animal Medical Center, 510 E 62nd St, New York, NY 10065. Address correspondence to Dr. Berent (allyson.berent@ amcny.org). CASE DESCRIPTION 3 cats were referred for evaluation of chronic urinary incontinence. CLINICAL FINDINGS A presumptive diagnosis of urethral sphincter mechanism incompetence (USMI) was made in all 3 cats. Preoperatively, incontinence was mild in 1 cat (incontinence during sleep) and moderate to severe (incontinence while awake and at rest) in 2. Structural abnormalities noted during cystoscopy included urethrovestibular junction stenosis (n = 1), vaginal stenosis (1), short urethra (1), and intrapelvic bladder (1). TREATMENT AND OUTCOME All 3 cats were treated by means of implantation of an inflatable silicone hydraulic occluder (HO) via a ventral midline celiotomy. Immediately prior to HO implantation, patients underwent cystoscopy to detect any anatomic abnormalities and confirm the absence of ureteral ectopia. Following surgery, all 3 patients attained complete continence, needing 0 or 1 inflation of the device. Complications included cystoscopy-associated urethral tear (n = 1), constipation (1), stranguria (1), hematuria (2), and urinary tract infection (2). Device explantation was performed 14 weeks after surgery in 1 cat because of postoperative constipation. Constipation persisted and urinary inconti- nence recurred but was markedly improved following device removal in this cat (leakage of urine only when sleeping at follow-up 29 months after surgery [26 months after device explantation]). At the time of last follow-up, 2 of the 3 cats remained fully continent approximately 3 and 6 years after device implantation. CLINICAL RELEVANCE Findings suggested that implantation of an HO may be a safe and effective long-term treatment for some cats with USMI. Further studies are necessary to evaluate the potential for treatment-related complications and the long- term outcome. (J Am Vet Med Assoc 2016;248:544–551) tion; and 10 = fully continent with no leakage). Prior treatment with PPA (2.2 mg/kg [1 mg/lb], PO, q 12 h) for 6 weeks had been unsuccessful, with minimal improvement in continence. Results of a CBC and se- rum biochemical analysis performed by the referring veterinarian were within reference limits. A urinaly- sis performed by the referring veterinarian indicated concentrated urine (urine specific gravity, 1.057; refer- ence range, 1.020 to 1.045) with an inactive sediment. Microbial culture of a urine sample did not yield any growth. On physical examination, the cat was bright and alert with normal vital parameters.A grade 2/6 systolic parasternal heart murmur was detected on thoracic auscultation. Urine leakage from the vulva was noted during the physical examination. Results of ultrasono- graphic examination of the abdomen were normal, with the urogenital anatomy appearing normal. Be- cause the cat had not responded to treatment with ABBREVIATIONS HO Hydraulic occluder device PPA Phenylpropanolamine USMI Urethral sphincter mechanism incompetence UTI Urinary tract infection