Multifocal Coccidioides immitis in a donkey (Equus asinus)

This case report discusses the clinical signs, diagnostic findings, treatment and outcome for a donkey (Equus asinus) diagnosed with coccidioidomycosis. At presentation, the donkey was lame, was in poor body condition, had a draining tract over the left femur and was hyporexic. Further investigation of the draining tract via radiography and ultrasonography showed a focal lesion of extensive bony proliferation and lysis on the mid-shaft of the left femur. There was also a soft tissue swelling over the fifth left rib. AGID titres were positive for Coccidioides immitis. Recommended treatment for C. immitis consists of two antifungal classes, the azoles and amphotericin B, with this donkey being prescribed daily fluconazole. A recheck 3 months from initial diagnosis showed marked improvement of clinical signs, but the C. immitis titre remained unchanged. The 18-month recheck showed improvement radiographically and significantly decreased titres. After 3 years of daily treatment of fluconazole, the C. immitis titre was decreased, but radiographs of the femur still showed persistent bony proliferation.