Info on Genetic Diseases our Dogs have tested carriers for.
While we don't want to add all the genetic diseases possible on our website, we do want to provide you with the information about the genetic diseases that our dogs do carry. It's meant to give you the information you need to move forward with decisions regarding our puppies. We don't want anyone to be unable to find the information they would like to have.
Angus carries a copy of the DM (Degenerative Myelopathy) gene. Below is a brief description of the disease. While a completely negative genetic panel would be nice, DM is a recessive trait, meaning that he will not ever develop the disease. In some breeds two copies of the gene have very detrimental results. Australian Shepherds show lower incidence of actually showing symptoms of the disease, even with two copies of the gene, meaning that there are many genetic factors that go into determining weather or not a dog will develop the disease.
All of our females are tested negative for the disease. So NONE of our puppies will be affected. We have talked long and hard about the implications of this for our program moving forward. While I refuse to breed an affected dog, there's more to a good dog than his or her genes. I'd rather pass on the traits that make a great working dog and partner than pick lesser individuals based on a piece of paper that says they're negative for everything. I use the genetic testing as a basis for making knowledgeable breeding decisions, and to help us not create an afflicted dog. Dominant genes or co-dominant genes would be a different story, but DM is recessive.
Below is from the Australian Shepherd Genetics Health Institute.
Rev. March 2014
Degenerative myelopathy, sometimes called chronic degenerative radiculomyelopathy, is an autoimmune disease that arises late in life and attacks the myelin, the “insulation” on the nerves. Dogs with DM may exhibit progressive weakness and lack of coordination in the hind limbs leading ultimately to paralysis. Euthanasia is required once the disease begins to impact breathing.
DM tends to be underdiagnosed in dogs, so ruling-out other potential causes of its symptoms is important. Diagnosis can be confirmed with a DNA test that detects a risk factor gene. Affected dogs will have two copies (not every dog that has two copies develops disease.) There is no effective treatment; long term care is palliative.
DM is a type of autoimmune disease. Autoimmune diseases are genetically predisposed; if a dog has the disease, it has the genes but the DM test allows breeders to identify a major risk factor for this particular disease. So far as we know at this point, while every dog with two copies of the DM gene develop spinal evidence of DM, not all of them become ill. Fortunately for Aussies they do so only occasionally, indicating that there are other genetic factors that help protect them from this disease. Having the mutation should be considered a fault with two copies being a greater fault than one. Dogs that have this mutation should only be bred to clear-tested mates. Because different autoimmune disease frequently occur in the same family, it would also be wise to avoid mates with a recent family history of any kind of autoimmune disease.