Corynebacterium urealyticum urinary tract infection in dogs and cats: 7 cases (1996-2003)

Objective-To identify clinical features of Corynebacterium urealyticum urinary tract infection in dogs and cats and antimicrobial susceptibility patterns of C urealyticum isolates. Design-Retrospective study. Animals-5 dogs and 2 cats. Procedure-Medical records of dogs and cats for which C urealyticum was isolated from urine samples were reviewed. Isolates from clinical cases, along with previously lyophilized unsubtyped isolates of Corynebacterium spp collected between 1977 and 1995, were examined and, if subtyped as C urealyticum, tested for antimicrobial susceptibility. Results-Signalment of infected animals was variable. Prior micturition disorders were common, and all animals had signs of lower urinary tract disease at the time C urealyticum infection was diagnosed. Median urine pH was 8.0; WBCs and bacteria were variably seen in urine sediment. In vitro antimicrobial susceptibility testing of 14 C urealyticum isolates revealed that all were susceptible or had intermediate susceptibility to chloramphenicol, tetracycline, and vancomycin and most were susceptible to enrofloxacin. Thickening of the bladder wall and accumulation of sediment were common ultrasonographic findings. Contrast radiography or cystoscopy revealed findings consistent with encrusting cystitis in 3 dogs. Infection resolved in 2 dogs following surgical debriclement of bladder plaques and antimicrobial administration. In 2 other dogs and 1 cat treated with antimicrobials, infection with C urealyticum resolved, but urinary tract infection with a different bacterial species developed. Conclusions and Clinical Relevance-Results suggest that preexisting urinary tract disorders are common in dogs and cats with C urealyticum infection. Treatment with appropriate antimicrobials in combination with surgical debridement might eliminate C urealyticum infection.