1. Department of Small Animal Clinical Sciences, College of Veterinary Medicine Michigan State University East Lansing Michigan USA
2. Department of Clinical Sciences, College of Veterinary Medicine Mississippi State University Mississippi State Mississippi USA
3. Greenville Animal Clinic and Hospital Greenville Mississippi USA
4. Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences Texas A&M University College Station Texas USA