Dog Degenerative Myelopathy Genetic Testing and Breeding

Genetic testing for degenerative myelopathy mutations enables responsible breeding that reduces the prevalence of this untreatable, welfare-compromising disease in affected breeds.

Key Facts

DM is caused by mutations in the SOD1 gene, with two known mutations (A and B) in dogs
Affected dogs are homozygous for the mutation; carriers have one copy and are unaffected
DNA testing is available through multiple commercial providers and breed health schemes
Not all dogs homozygous for the mutation develop clinical DM, suggesting other genetic modifiers
German shepherds, Pembroke Welsh corgis, Boxers, and Chesapeake Bay retrievers are among the most affected breeds

Welfare Considerations

Genetic testing for DM enables breeders to make informed decisions that prevent producing homozygous affected offspring over successive generations. By avoiding breeding two carriers or affected dogs together, the proportion of dogs at risk of developing DM can be reduced without eliminating all carriers from the breeding population immediately. This is the same principle applied successfully in other hereditary disease control programmes. The welfare benefit accumulates across generations as the frequency of the mutation in the breed population declines. Breed clubs that integrate DM testing into health schemes and make results publicly accessible facilitate progress at industry scale.

What You Can Do

Request DM genetic test results from breeders when acquiring a puppy from an at-risk breed
DNA test dogs before breeding and avoid producing homozygous affected offspring
Support breed club health screening initiatives that include DM testing
Advocate for kennel club registration requirements that include DM test results for affected breeds