Risk factors for positive urine cultures in cats with subcutaneous ureteral bypass and ureteral stents (2010-2016).

BACKGROUND: Ureteral stent and subcutaneous ureteral bypass (SUB) placement are commonly used for managing ureteral obstructions. Urinary tract infection (UTI) is a recognized complication.

OBJECTIVES: To determine postoperative incidence of positive urine cultures in cats undergoing ureteral stent and SUB placement and to identify risk factors associated with positive urine cultures.

DESIGN: Retrospective study.

ANIMALS: Forty-three cats that underwent 48 surgical events.

PROCEDURES: Medical records were reviewed. Cats were included if urine cultures were performed before and after surgery. Variables were compared to identify risk factors.

RESULTS: Urine cultures were positive postoperatively pre-discharge in 5/20 (25%) cats. Median duration of follow-up post-discharge was 209 days (range, 11-2184 days), with a total of 143 urine cultures performed in cats post-discharge. Of these, 16 (11%) were positive in 12/48 (25%) cats. Nine different bacteria were identified; Enterococcus spp. (n = 8) predominated as monomicrobic or mixed infections. In 14/16 instances of positive urine cultures, affected cats had lower urinary tract signs, signs of pyelonephritis or both. Cats that received antibiotics postoperatively were significantly less likely to have a positive urine culture compared to those that did not (odds ratio, 0.2, 95% confidence interval, 0.05, 0.8, P = 0.02). Chronic kidney disease, renal implant type and postoperative urinary catheterization were not associated with positive urine cultures.

CONCLUSIONS AND CLINICAL RELEVANCE: Postoperatively, occurrence of positive urine cultures was similar to previous reports. Subclinical bacteriuria was less common than UTI. Postoperative urinary catheterization has been speculated to increase risk of bacteriuria, but this was not the case in this cohort.