Coccidioidomycosis in a black rhinoceros (Diceros bicornis)

Abstract: A 5-yr-old female black rhinoceros (Diceros bicornis) was euthanized 11 mo after arrival at the Milwaukee County Zoo (Milwaukee, Wisconsin, USA) from Glen Rose, Texas (USA) for a severe progressive rear leg lameness of 6-mo duration. Gross necropsy revealed complete rupture of the capital ligament of the left femur with synovitis and osteomyelitis. Multifocal lymphadenopathy with chronic suppurative lymphadenitis of the tracheobronchial, left supramammary, and iliac lymph nodes was present. Granulomatous pneumonia with a focal abscess was also noted. Histologically, fungal elements were seen in the lung, lymph nodes, and synovium, and Coccidioides immitis was isolated on fungal culture. Coccidioides immitis is not endemic to Wisconsin; therefore, the animal had to have been infected, although asymptomatic, at the time of arrival at the Milwaukee County Zoo. Whether the disease was active at the time of arrival or whether it was quiescent and then became active with the stress of shipment or injury is unknown.