To determine reliability of preliminary evaluations for canine hip dysplasia (CHD) performed by the Orthopedic Foundation for Animals on dogs between 3 and 18 months of age.
Retrospective analysis of data from the Orthopedic Foundation for Animals database.
2,332 Golden Retrievers, Labrador Retrievers, German Shepherd Dogs, and Rottweilers for which preliminary evaluation had been performed between 3 and 18 months of age and for which results of a definitive evaluation performed after 24 months of age were available.
Each radiograph was evaluated, and hip joint status was graded as excellent, good, fair, or borderline phenotype or mild, moderate, or severe dysplasia. Preliminary evaluations were performed by 1 radiologist; definitive evaluations were the consensus of 3 radiologists. Reliability of preliminary evaluations was calculated as the percentage of definitive evaluations (normal vs dysplastic) that were unchanged from preliminary evaluations.
Reliability of a preliminary evaluation of normal hip joint phenotype decreased significantly as the preliminary evaluation changed from excellent (100%) to good (97.9%) to fair (76.9%) phenotype. Reliability of a preliminary evaluation of CHD increased significantly as the preliminary evaluation changed from mild (84.4%) to moderate (97.4%) CHD. Reliability of preliminary evaluations increased significantly as age at the time of preliminary evaluation increased, regardless of whether dogs received a preliminary evaluation of normal phenotype or CHD.
Results suggest that preliminary evaluations of hip joint status in dogs are generally reliable. However, dogs that receive a preliminary evaluation of fair phenotype or mild CHD should be reevaluated after 24 months of age. (J Am Vet Med Assoc 1997;211:1142–1146)
Objective—To determine in dogs what effect using
hip conformation scores assigned by the Orthopedic
Foundation for Animals (OFA) as a criterion for breeding
selections would have on hip conformation scores
of the progeny.
Animals—English Setters, Portuguese Water Dogs,
Chinese Shar-peis, and Bernese 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 score
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 time of radiographic evaluation and year
of birth had a significant effect on hip joint conformation
of the progeny. Estimated heritability (mean ± SE)
was 0.26 ± 0.03, and dam and sire hip conformation
scores had a significant effect on progeny hip conformation
scores. Annual decreases in percentage of
dysplastic progeny and increases in percentages of
progeny and breeding dogs with phenotypically normal
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
with better hip conformation scores will increase the
percentage of progeny with phenotypically normal hip
joint conformation. (J Am Vet Med Assoc 2000;