1. Department of Clinical Sciences and Services, Royal Veterinary CollegeUniversity of London North Mymms Hertfordshire UK
2. Department of Surgical and Radiological Sciences, Davis, School of Veterinary MedicineUniversity of California Davis California USA
3. Department of Small Animal Clinical SciencesUniversity of Tennessee Knoxville Tennessee USA
4. Department of Veterinary Biosciences and Diagnostic ImagingUniversity of Georgia College of Veterinary Medicine Athens Georgia USA