Anthropometric measurements of the scapula, humerus, radius and ulna in Labrador dogs with and without elbow dysplasia

Abstract

To determine if anthropometric measurements of the Labrador scapula, humerus, ulna and radius, or their ratios, are related to the presence of elbow dysplasia (ED). Digital calliper measurements of the lengths of the left scapula, humerus, radius and ulna, and their ratios, were analysed by gender in 103 volunteer Labradors (41 dogs, 62 bitches) against the ED radiological scores derived by the International Elbow Working Group (IEWG). The IEWG score is an umbrella score used to classify for ED and includes fragmented coronoid process, osteochondritis dessicans, incongruity and ununited anconeal process, the last of which occurs rarely in Labradors. Of the 103 Labradors studied, 31 were diagnosed radiographically with ED (20 bitches (32%), 11 (27%) dogs). Scapula length was significantly shorter for bitches with ED (P = 0.02), but not for dogs with ED. However, dogs showed a trend for a difference in the ulna:radius ratio (P = 0.06), which bitches did not. Although a greater percentage of bitches than dogs had ED in this study, the difference was not statistically significant. Labrador bitches diagnosed with ED have a shorter scapula, which is a new finding associated with this condition. The difference in presentation associated with gender is unexpected and further research is recommended.