1. Washington Animal Disease and Diagnostic Laboratory, Washington State University, Pullman, Washington 99164-7034, USA
2. Current address: Diagnostic Medicine Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 1644 Campus Delivery, Fort Collins, Colorado 80523-1644, USA
3. Washington Department of Fish and Wildlife, 2315 N Discovery Pl., Spokane Valley, Washington 99216-1566, USA