Coccidioidomycosis in alpacas in the southwestern United States

Abstract

An anonymous web-based survey of alpaca owners was used to learn more about the clinical presentation, diagnosis, and treatment of coccidioidomycosis in alpacas in the United States. Thirty-seven owners, with 1,117 alpacas, completed the survey. Over 4% of alpacas included in the study were diagnosed with coccidioidomycosis between 2005 and 2016 (5 post mortem, 46 clinically). Immunodiffusion titers ranged from 1:4 to >= 1:256 in sick animals. Alpacas residing in Arizona counties with a high incidence of human disease were 5.8 times more likely to contract coccidioidomycosis than animals residing in other areas of the state. Treatment was reported in 23 alpacas, and 78% of those animals died or were euthanized. Necropsy records from a veterinary diagnostic laboratory in Tucson, AZ were reviewed to estimate the severity of disease in this species. Nine cases identified for review died of disseminated coccidioidomycosis; the disease was extensive in most animals, with the lungs, lymph nodes, and liver the most frequently affected. Alpacas appear to be highly susceptible to severe illness as a result of infection by Coccidioides spp., frequently resulting in death. More research is needed to better understand the epidemiology, clinical signs, and treatment protocols for coccidioidomycosis in alpacas.