Three different scoring systems for elbow dysplasia and its radiographic signs were genetically evaluated in 2645 German shepherd dogs.
An animal model was used to estimate heritabilities and additive genetic and residual correlations for the three scoring systems: ED-SV, which is recommended by the International Elbow Working Group; ED-LA, developed by Lang and others; and ED-TH, proposed by Tellhelm.
Results: The effects of sex, age at examination and the correlation between the two factors were significant for all three scoring systems.
Heritability estimates (se) were 0路18 (0路04) for ED-SV, 0路11 (0路03) for ED-LA and 0.16 (0路04) for ED-TH.
The additive genetic correlations among the different single criteria for elbow dysplasia and the different elbow dysplasia scores were between 0路68 and 0路98, except for the criteria ununited anconeal process and osteochondrosis dissecans of the trochlea humeri, which were mostly genetically negatively correlated to the other radiological criteria.
The elbow dysplasia scores were determined by two genetically different traits. The possibilities for selecting German shepherd dogs with respect to elbow dysplasia might be improved by taking into account these two traits in the prediction of breeding values.
Source: Janutta, V., Hamann, H., Klein, S., Tellhelm, B. & Distl, O. (2006): Genetic analysis of three different classification protocols for the evaluation of elbow dysplasia in German shepherd dogs. In: Journal of Small Animal Practice 47 (2), 75-82.
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