1. Department of Clinical Sciences Iowa State University College of Veterinary Medicine Ames Iowa USA
2. College of Veterinary Medicine, Department of Veterinary Medicine and Surgery University of Missouri Columbia Missouri USA
3. College of Veterinary Medicine, Department of Clinical Sciences Texas A&M University College Station Texas USA
4. College of Veterinary Medicine, Department of Clinical Sciences University of Tennessee Knoxville Tennessee USA
5. College of Veterinary Medicine, Department of Clinical Sciences North Carolina State University Raleigh North Carolina USA