1. From the Veterinary Diagnostic Laboratory (Anderson, Blanchard, Layton, McAllister, Daft, Kinde, Read, Barr), and the Departments of Medicine and Epidemiology (Thurmond, Picanso), and Pathology, Microbiology, and Immunology (Conrad), School of Veterinary Medicine, University of California, Davis, CA 95616; California Department of Food and Agriculture (Palmer, Breitmeyer), 1220 N St, Sacramento, CA 94271; and the Parasite Biology and Epidemiology Laboratory (Dubey)...