1. *Departments of Veterinary Clinical Sciences, Louisiana State University, Baton Rouge, LA 70803–8410, U.S.A.
2. †Departments of Veterinary Pathology and the Louisiana Veterinary Medical Diagnostic Laboratory, Louisiana State University, Baton Rouge, LA 70803–8410, U.S.A.
3. ‡Departments of Veterinary Microbiology and Parasitology, Louisiana State University, Baton Rouge, LA 70803–8410, U.S.A.