1. Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843.
2. Department of Veterinary Biomedical Sciences, College of Veterinary Medicine Long Island University, Brookville, New York 11548.
3. Animal Health Diagnostic Center, Department of Population Medicine and Diagnostic Sciences, Cornell University College of Veterinary Medicine, Ithaca, New York 14850.
4. Museum of Southwestern Biology and Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131.
5. Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary. 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada.