Outcomes of medical dissolution for suspected struvite uroliths in dogs using a therapeutic multipurpose urinary diet and antimicrobial therapy.

Abstract

BACKGROUND: The consensus recommendation is to medically dissolve suspected struvite uroliths in dogs. However, more data is needed on outcomes for protocols using therapeutic multipurpose urinary foods formulated for both struvite urolith dissolution and calcium oxalate urolith prevention. HYPOTHESIS/OBJECTIVES: To describe outcomes for medical dissolution of suspected struvite uroliths in dogs using a therapeutic multipurpose urinary food and concurrent or recent antimicrobial therapy. ANIMALS: Thirteen client-owned dogs with suspected struvite uroliths. METHODS: Single-institution, retrospective case series (observational) of dogs fed a therapeutic multipurpose urinary food for dissolution of suspected struvite uroliths. Dogs had to be treated with antimicrobials concurrently or have an absence of bacteriuria on urine microbial culture after recently completed antimicrobial therapy. Follow-up abdominal imaging was required. Patient and urolith characteristics, dissolution outcomes, and complications were summarized. RESULTS: Complete urolith dissolution occurred in 9 (8 with cystoliths and 1 with nephroliths) of 13 dogs included in the study. Mean time until documentation of complete dissolution was 71 ± 52 days. Eight of the dogs with complete dissolution had bacteriuria less than 60 days prior to urolith diagnosis. Mean duration of antimicrobial therapy for dogs with successful dissolution was 66 ± 49 days. All dogs without complete dissolution had uroliths with non-struvite shells (composed of 80%-100% calcium). No dog developed a urethral obstruction during the dissolution trial. CONCLUSIONS AND CLINICAL IMPORTANCE: Struvite uroliths can be effectively dissolved in dogs with a therapeutic multipurpose urinary food and antimicrobial therapy. A non-struvite urolith layer is a common cause of unsuccessful dissolution.