Curiosity or Cure? — The scoop on DNA testing for dogs.

On your morning walk at Chatfield Hollow, you meet a very cute and unique looking dog.  After learning his name and giving him a pat on the head, your next question, of course, is to ask what breed he is.  Years ago the answer would have been a matter of speculation, but now thanks to the expanding technology of dog genetic testing the information is available and may be surprising!

Over the past ten years or so the science of DNA testing has exploded, and genetic tests for humans and dogs are readily available and becoming very popular.  More families are adopting dogs from shelters than ever before, and the bloodlines of these dogs are typically unknown.  Finding out your dog’s genetic background is relatively simple: a DNA blood test can be ordered by your veterinarian, or cheek swab test kits can be purchased online or at pet supply stores.   As a result, genetic breed testing for dogs is becoming commonplace and even somewhat trendy.

So what is the benefit of knowing what mix of breeds your dog might be?  Aside from being a fun conversation starter, knowing your dog’s genetic heritage can be helpful for predicting the size of a growing puppy or the behavioral tendencies of a rescue dog you don’t know well. Your veterinarian might recommend different nutrition based on size and breed, or training techniques based on the genetic breed make up of your dog. Many canine medical conditions are breed-related, so knowing his genetic makeup could help owners keep an eye out for symptoms of a future problem.

How accurate are the tests?  There are many brands of test kits available, and the certainty of test results varies, especially with over the counter cheek swab tests.  DNA blood tests ordered by your veterinarian are likely to be the most accurate.  So, if your 90 pound shelter dog’s breed test says that he is 60% Yorkshire terrier, the results may be questionable!

An entirely different aspect of DNA testing for specific genetic diseases has become a mainstream part of veterinary medicine.  Over the thousands of years that dogs have been domesticated and bred by humans, selection for desirable breed traits has also inadvertently selected for certain genetic defects which can cause medical conditions in our pets.  Over 200 canine diseases caused by genetic defects have been identified, and more are being discovered all the time.  DNA tests can help veterinarians diagnose and treat these medical problems, and can help responsible dog breeders to avoid passing these defects into future generations of dogs.  This is a great way that technology can help our pets live healthier, happier lives.  Some examples of genetic diseases we can test for include hereditary eye diseases, bleeding disorders, heart diseases, and a common progressive neurological disorder called degenerative myelopathy.  Another example is a mutation in the gene known as MDR-1, which is common in Collies, Australian shepherds, and Border Collies.  This genetic defect can cause otherwise healthy dogs to be more sensitive to certain medications and sedatives.  Now that we can test for this defect we can avoid problems when anesthetizing or prescribing medications for these animals.

Interpretation of genetic tests can be tricky, and sometimes testing can do more harm than good!  Many genetic defects need two copies of the bad gene in order to cause trouble, so a carrier with one copy may be perfectly healthy.  In other cases there may be milder symptoms of disease with one bad gene copy.  Also external factors like nutrition and environment can play a role in the development of symptoms of some genetic diseases.  Life and death decisions should never be made based on genetic testing alone, and medical genetic test results should be cautiously interpreted with the help of a veterinarian.

The bottom line is that genetic testing for dogs is becoming mainstream.  This evolving technology is an interesting way to unlock the mystery of your dog’s heritage, as well as another effective tool for your veterinarian to help keep your dog as happy and healthy as possible.