1. From the James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York; and the2School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
2. From the James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York; and the
3. School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.