Prospective comparison of four sampling methods (cystocentesis, bladder mucosal swab, bladder mucosal biopsy, and urolith culture) to identify urinary tract infections in dogs with urolithiasis.

A prospective study was conducted on 27 dogs with recurrent urinary tract infections (UTIs) and urolithiasis. Four sampling methods (i.e., urine obtained by cystocentesis, bladder mucosal swab, bladder mucosal biopsy, and urolith) were compared to identify UTI. Identical culture results were obtained from urine collected by cystocentesis and from the swab of bladder mucosa. In the presence of a positive urine culture, the same organism also was cultured from the bladder mucosal biopsy and urolith. However, in the presence of a negative urine culture, an organism was cultured from the bladder mucosal biopsy or the urolith in 18.5% of the cases. Therefore, when the culture from urine obtained by cystocentesis is negative, it is recommended that aerobic cultures of a bladder mucosal biopsy and a urolith be performed in cases of urolithiasis.