Prevalence and inheritance of and selection for elbow arthrosis in Bernese Mountain Dogs and Rottweilers in Sweden and benefit:cost analysis of a screening and control program

Abstract

Objective To determine the prevalence and changes over time in the prevalence of elbow arthrosis in Bernese Mountain Dogs and Rottweilers, to ascertain whether prevalence or severity of elbow arthrosis was associated with sex of the dogs, age at the time of elbow joint examination, or ancestral background, to determine the effects of selective breeding, and to conduct an economic evaluation of the elbow arthrosis program operated by the Swedish Kennel Club. Design Analysis of radiographic evaluations of elbow joint conformity. Animals 4,515 dogs from 2 breeds registered by the Swedish Kennel Club. Procedure All radiographs were scrutinized by a single radiologist (LA), and elbow joint conformation was classified as normal or arthrotic, with the degree of arthrosis classified as 1, 2, or 3. Results Decreasing prevalence of elbow arthrosis corresponding to selection of breeding stock and high heritabilities was found. Sex differences were documented in both breeds, but with contradictory directions. This was interpreted as breed differences in the distribution of genes related to elbow arthrosis. Economic analyses showed that costs of screening and registration of elbow joints was less than the value of dogs estimated to have been saved from moderate and severe elbow arthrosis in both breeds. Clinical Implications Documented effects of age suggest that all dogs should be screened at the same age, rather than screening a few dogs at an older, more revealing age. In screening and control programs based on an open registry with access to family records, decreasing prevalence of elbow arthrosis can be expected, and related to selection of breeding stock.