Effect of dam and sire qualitative hip conformation scores on progeny hip conformation

Objective-To determine in dogs what effect using hip conformation scores as signed by the Orthopedic Foundation for Animals (OFA) as a criterion for br eeding selections would have on hip conformation scores of the progeny. Design-Longitudinal study. Animals-English Setters, Portuguese Water Dogs, Chinese Shar-peis, and Bern ese Mountain Dogs for which OFA hip conformation scores were known. Procedure-Pedigree data were obtained from the national breed clubs and the American Kennel Club and merged with data from the OFA hip conformation sc ore database. An ANOVA was used to evaluate the effects of sex, age at the time of radiographic evaluation, and year of birth on the variation in hip conformation scores among the progeny. Heritability was estimated by use of within-year midparent offspring regression analyses. Results-Significant differences in progeny hip conformation scores between sexes were not detected, but age at the lime of radiographic evaluation and year of birth had a significant effect on hip joint conformation of the pr ogeny. Estimated heritability (mean +/- SE) was 0.26 +/- 0.03, and dam and sire hip conformation scores had a significant effect on progeny hip confor mation scores. Annual decreases in percentage of dysplastic progeny and inc reases in percentages of progeny and breeding dogs with phenotypically norm al hip joint conformation were detected. Conclusions and Clinical Relevance-Results indicated that hip conformation scores have moderate heritability in dogs and selection of breeding stock w ith better hip conformation scores will increase the percentage of progeny with phenotypically normal hip joint conformation.