Control of inherited defects in dogs

Canine defects can be divided into several main groups: autosomal recessives, autosomal dominants, sex‐linked traits, threshold characters and polygenic traits. Few are dominant, as early onset dominant defects are easily eliminated. Autosomal recessives are almost impossible to eradicate, though incidence reduction is feasible. Biochemical tests, though potentially rewarding, are not likely to be in widespread use for many years. Test mating of sires for autosomal recessives can be effective but in many late onset, or rare defects, becomes quite impracticable. The paper argues for more extensive breed recording, as the assessment of sires used on random numbers of mates can be an effective system of control for many traits simultaneously. Sex‐linked traits like haemophilia A can be tested for with success but at some cost. Polygenic traits, hip dysplasia is used as an example, are best tackled by breed schemes on a large scale and by the employment of progeny testing results to follow up performance testing. The need for ruling bodies to introduce legislation to aid dogdom is long overdue, especially in Britain and criticism of the Kennel Club is made.