Stuart C. Jeffreyfrom the Marion duPont Scott Equine Medical Center, Virginia-Maryland Regional College of Veterinary Medicine, PO Box 1938, Leesburg, VA 22075;
Martin O. Furrfrom the Marion duPont Scott Equine Medical Center, Virginia-Maryland Regional College of Veterinary Medicine, PO Box 1938, Leesburg, VA 22075;
Martha L. Moonfrom the Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061.