1. Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
2. Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
3. Animal Health Diagnostic Center, Cornell University College of Veterinary Medicine, Ithaca, NY, USA
4. Myhre Equine Clinic, Rochester, NH, USA
5. Maple Hill Veterinary Service, Danville, VT, USA