Clinical significance of bacteriuria in dogs, risk factors and antimicrobial susceptibility.

The objectives of this study were to describe the antimicrobial susceptibility and clinical significance of in canine bacteriuria and to identify the risk factors associated with urinary tract infections. This is a retrospective observational study of 48 -positive canine urinary cultures. Only 22 of the 48 isolates (45.8%) were non-susceptible to at least one tested antimicrobial. Most isolates (98%) were susceptible to enrofloxacin, 93.7% to amoxicillin/clavulanic acid, and 85.4% to ampicillin, cephalothin, and trimethoprim-sulfamethoxazole. Five multidrug-resistant isolates were detected (10.4%). A significant increase in antimicrobial resistance was observed over the study period. Positive cultures were associated with bacterial cystitis in 36 of 39 dogs (92.3%), pyelonephritis in 2 of 39 dogs (5.1%), and one dog had both bacterial cystitis and pyelonephritis (2.5%). There was no subclinical bacteriuria. Most urinary tract infections were complicated as risk factors were identified in 37 of 39 dogs (94.8%). The most commonly identified risk factors were the presence of a contaminated peri-vulvar area with urine/feces or a hypoplastic vulva. To conclude, bacteriuria was associated with upper and lower urinary tract infections in this study and was found more frequently in complicated bacterial cystitis. Multidrug-resistant isolates and increased antimicrobial resistance have been identified over the last 10 years, but most isolates remain susceptible to first-line antimicrobials such as amoxicillin and trimethoprim-sulfamethoxazole.