1. Georga T. Karbe Med Vet, 2. Darryl N. Biery DVM, Diplomate ACVR, 3. Thomas P. Gregor BS, 4. Urs Giger Dr med vet, Diplomate ACVIM, ECVIM & ECVCP, 5. Gail K. Smith VMD, PhD* Gail Smith, VMD, PhD, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 3900 Delancey St, Philadelphia, PA 19104-6010 Vet Surg January 2012 41 1 34-41 Objective To investigate the radiographic hip joint phenotype of the Pembroke Welsh Corgi. Study Design Prospective and retrospective cross-sectional study. Animals Pembroke Welsh Corgis (n = 399). Methods Ventrodorsal, hip-extended radiographs were evaluated for subluxation, osteoarthritis (OA), caudolateral curvilinear osteophytes (CCO), and circumferential femoral head osteophytes (CFHO) of PennHIP evaluated Corgis. Joint laxity was measured by distraction index (DI). Results All Corgis had DI > 0.30 (mean, 0.66), 6.8% had OA, 18% had subluxation, 22.3% had CCO, and 74.4% had CFHO. Higher DI increased the odds for subluxation and canine hip dysplasia (CHD) but not for OA, CCO, or CFHO. The presence of CCO increased the odds for OA by 4.6 times (P = .002) and 2.2 times (P = .01) for hip dysplasia. All dogs with OA had CFHO. The presence of CFHO increased the odds for subluxation by 8.7 times (p < .001) and 8.9 times (P < .001) for hip dysplasia. Subluxation increased the odds for OA by 15.4 times (P < .001). Conclusion Corgis had a low frequency of conventional OA despite having hip laxity that has been shown to correlate with hip OA and hip dysplasia in large-breed dogs. The relationship between CCO and OA was similar to published findings in nonchondrodystrophic large-breed dogs and the CFHO was significantly associated with subluxation. Both CCO and CFHO are associated with hip dysplasia in this small chondrodystrophic breed.

• Hip