Assessment of serum symmetric dimethylarginine and creatinine concentrations in cats with urethral obstruction.

OBJECTIVES: The aims of this study were to evaluate serum symmetric dimethylarginine (SDMA) and creatinine concentrations in cats with urethral obstruction pre- and post-decompression of the obstruction, and to determine if pre-decompression values were predictive of post-decompression renal function, as measured by SDMA and creatinine. METHODS: This was a prospective observational study. Twenty-five client-owned cats with urethral obstruction were hospitalized for decompression of the obstruction. Serum SDMA and creatinine were prospectively assessed at presentation, 24 h post-decompression and 5-20 days post-decompression. Urinalysis and culture were assessed at presentation and at the final follow-up. Exclusion criteria included positive urine culture, reobstruction or failure to obtain required samples. RESULTS: Mean SDMA concentration dropped by 41.8% from an initial pre-decompression concentration of 17.6 µg/dl to 10.3 µg/dl 24 h post-decompression (P <0.001). The mean creatinine value dropped by 38.4% from an initial pre-decompression concentration of 2.5 mg/dl to 1.5 mg/dl 24 h post-decompression (P <0.001). There was no association between SDMA concentration at initial presentation and SDMA concentration 5-20 days after urethral catheterization (Spearman's ρ = 0.205, P = 0.314). Creatinine concentration upon initial presentation was associated with the 5-20 day values after urethral catheterization (Spearman's ρ = 0.583, P <0.002). Twenty percent of cases were excluded due to bacterial growth on initial urine culture. SDMA and creatinine concentrations were significantly higher in these cases (median 59 µg/dl and 10.9 mg/dl, respectively) compared with those with negative cultures (median 14 µg/dl and 1.6 mg/dl [P <0.002 and P <0.001], respectively). CONCLUSIONS AND RELEVANCE: Both SDMA and creatinine decreased significantly after urethral catheterization, suggesting that renal function post-decompression cannot be predicted by the pre-decompression concentrations of these values.

Use of a percutaneously controlled hydraulic occluder for treatment of refractory urinary incontinence in three female cats.

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 incontinence 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.