Successful treatment of encrusted cystitis associated with Staphylococcus pseudintermedius infection in the urinary bladder of a dog

Case Description-A 5-year-old female spayed mixed-breed dog was examined because of signs of persistent stranguria following treatment for urethral obstruction. Clinical Findings-Radiographic, ultrasonographic, cystoscopic, and histologic findings were consistent with encrusted cystitis. Results of bacteriologic culture of urine and bladder wall biopsy samples indicated growth of Staphylococcus pseudintermedius. Treatment and Outcome-The dog was initially treated via IV administration of fluids, placement of an indwelling urinary catheter, lavage of the bladder with sterile saline (0.9% NaCl) solution, and administration of antimicrobial drugs and bethanechol (to improve voiding of urine from the bladder). Antimicrobial drugs were administered for 3 months, and a commercially available diet for dissolution of urinary calculi was fed. Clinical signs of encrusted cystitis gradually resolved during the 3 months after the initial examination. Results of urinalysis and abdominal ultrasonographic examination performed 4 months after the initial examination indicated resolution of the disease. Clinical Relevance-Encrusted cystitis is extremely rare in small animals and has previously only been associated with Corynebacterium spp infection of the urinary bladder. Resolution of encrusted cystitis has previously been achieved via surgical debridement of the bladder and treatment with antimicrobial drugs. The clinical findings and successful resolution of clinical signs in the dog of the present report suggested that urease-positive bacteria other than Corynebacterium spp can cause encrusted cystitis and that feeding of a diet for dissolution of urinary calculi in conjunction with antimicrobial treatment may result in resolution of urinary bladder lesions and clinical signs attributable to the disease without the need for surgical debridement of encrusted plaques.