Genetic researchers at the Animal Health Trust (AHT) have discovered a genetic mutation for cerebellar ataxia in Norwegian Buhunds and now the launch of a new DNA test could protect this small breed from the threat of affected puppies.
The neurological disease affects dogs as young as 12 weeks of age, with uncoordinated movement and head tremors. There is currently no effective treatment and the disease is progressive, worsening over time. Affected animals are often euthanised on welfare grounds.
Hereditary cerebellar ataxia appears recessive in Norwegian Buhunds, which means that two copies of the mutation need to be inherited by a dog (one from each parent) for him to be clinically affected. If two carriers are mated there is a chance that affected puppies will be produced, and DNA testing is the best way to prevent this.
The AHT tested 146 Norwegian Buhunds for the mutation, including 70 UK dogs whose samples were taken between 2008 and 2015, and 36 UK dogs whose samples were taken in 2017. Carriers were identified in all sets showing that the mutation is still present but none of the dogs in the study had two copies of the mutation.
Margaret Deuchar, Norwegian Buhund Breed Health Coordinator, said, "The Norwegian Buhund Club of [the] UK is extremely grateful to the AHT for carrying out this research project into cerebellar ataxia in our breed.
"Although we have not been aware of any clinically affected puppies in the last few years the research has confirmed that we do still have carrier dogs in the present population, meaning an affected puppy could arise at any time. With the DNA test now available we can prevent another puppy suffering this horrendous condition and hopefully over a number of years progressively reduce the prevalence of the mutant recessive gene - without making our numerically small gene pool even smaller, and thus putting the breed at increased risk of different genetic diseases."
The cause was identified by geneticists at the Kennel Club Genetics Centre, in collaboration with the AHT's Neurology unit, and the DNA test was made available earlier this week. You can order the test from here.
Dr Cathryn Mellersh, Head of Canine Genetics at the AHT, said, "The mutation for this inherited disease in the Norwegian Buhund has been identified using whole genome sequencing, and the study was facilitated by the genome bank that we are developing as part of our Give a Dog a Genome project. Without the Give a Dog a Genome data it would have taken us much longer to track down the causal mutation and develop this test. We’re very happy to be able to help this breed swiftly eliminate any potential carriers, and therefore affected dogs with cerebellar ataxia, and to demonstrate that whole genome sequencing really works as a method of speeding up mutation identification and developing new DNA tests."
Caroline Kisko, Kennel Club Secretary, said, "It is very good news for the breed that the genetic mutation for cerebellar ataxia has been identified. We would encourage breeders of Norwegian Buhunds to utilise this DNA test, as identifying possible carriers in the breed will help to prevent any more puppies being born with this horrible disease.
"The Kennel Club Genetics Centre at the Animal Health Trust is making strides in genetic research, which enables breeders to make sensible breeding decisions and will go a long way in helping to protect the future of dog health."
If you sent a DNA sample of your Norwegian Buhund for the cerebellar ataxia research, you can now find out, free of charge, if your dog carries the mutation. Go here to download and return a request for your result.
Photo: Norwegian Buhund, AHT