Canine multiple system degeneration (Kerry blue terrier type) is a progressive inherited neurological disease affecting Kerry blue terriers. Affected dogs present at 3 to 6 months of age with tremors, abnormal gait and poor balance. Dogs gradually progress to severe gait abnormalities and balance issues, frequent falling, abnormal body posture, abnormal eye movement and eventually, are unable to move. Dogs continue to show normal mental awareness and social behavior despite movement disturbances. Most dogs die due to disease complications or are humanely euthanized by 2 years of age.
Genetic testing of the SERAC1 gene in Kerry blue terriers will reliably determine whether a dog is a genetic Carrier of canine multiple system degeneration (Kerry blue terrier type). Canine multiple system degeneration (Kerry blue terrier type) is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the SERAC1 gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Kerry Blue Terriers that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
Johnson GS, Mhlanga-Mutangadura T, Morava E, Kozicz T, Taylor JF, O’Brien DP, Schnabel RD. Canine Multiple System Degeneration is Associated with Distinct SERAC1 Mutations in Two Different Dog Breeds [abstract]. Presented at the 63rd Annual Meeting of the American Society of Human Genetics in Boston, Massachusetts; 2013 Oct 22-26.