Treatment of Disseminated Aspergillosis with Posaconazole in 10 Dogs

Abstract

BACKGROUND: Few effective treatments for disseminated Aspergillus infections in dogs are available. Posaconazole has potent and broad-spectrum activity against Aspergillus spp., but its use has not yet been sufficiently evaluated in dogs. HYPOTHESIS/OBJECTIVES: The aim of this study was to determine the safety and efficacy of posaconazole for the treatment of naturally occurring disseminated Aspergillus infections in dogs. ANIMALS: Ten client-owned dogs with disseminated aspergillosis. METHODS: Prospective, nonrandomized, noncontrolled study with posaconazole administered to dogs at dosage of 5 mg/kg p.o. q12h. The primary veterinarian or the veterinary specialist caring for the dogs provided patient data. RESULTS: The treatment response for dogs with disseminated disease while receiving posaconazole was defined as clinical remission (n = 4) and clinical improvement (n = 6). There was a high rate of relapse during treatment or after cessation of treatment in both groups, and most dogs died or were euthanized due to progressive disease. Excluding 1 dog concurrently treated with terbinafine that remains alive 5 years after diagnosis, the mean survival time for dogs was 241 days (range 44-516 days). Three other dogs lived >1 year after starting treatment. No clinically relevant adverse events or increases in serum liver enzyme activity occurred during treatment with posaconazole. CONCLUSIONS AND CLINICAL IMPORTANCE: Posaconazole appears to be safe and well-tolerated for treatment of disseminated Aspergillus infections in dogs. Long-term survival >1 year is possible with prolonged treatment, but relapse is common.