Novel Presentation of Coccidioidomycosis with Myriad Free-Floating Proteinaceous Spheres in the Pericardial Sac of a Southern Sea Otter (Enhydra lutris nereis).

A southern sea otter (Enhydra lutris nereis) stranded dead in central California, USA, with a distended pericardial sac containing thousands of free-floating proteinaceous masses. Serology, fungal culture, PCR, and sequencing confirmed the etiology of this novel lesion as Coccidioides immitis. Range expansion of this zoonotic pathogen is predicted with climate change.