(SAN ANTONIO, Aug. 9, 2016, AVMA Annual Convention)
Just like doctors can tell humans what diseases they are predisposed to, a vet will soon be able to tell how likely a dog is to develop heart disease, allergies or hip dysplasia.
“Veterinarians are becoming savvier in understanding genetic predispositions,” said Dr. Jerold Bell, a small animal practitioner and adjunct professor at the Tufts University Cummings School of Veterinary Medicine.
Today, one affected animal can be diagnosed, its DNA sequenced and a disease-causing mutation identified that can benefit entire breeds. “The price tag of gene searching and genetic testing has dropped exponentially,” said Dr. Bell, “making it easier to breed healthier pets and minimize the chance of common disorders.”
Although hip dysplasia and diabetes may occur more often and affect all breeds, most eye diseases are caused by single genes and have no cure or treatment. They have to be bred out of existence, and therein lies the reason why genetic research on companion animals has enjoyed a long-term relationship with the eye.
How Genetic Testing for Dogs Can Be Used
With documented breed-improving results, it is no wonder responsible breeders have jumped on the genetic testing bandwagon. They, too, can keep veterinarians informed about what disorders are occurring in their own animals. “In my view, the most important aspect of breeding is to produce healthy pets,” said Dr. Bell. “As the pet-owning public becomes more aware of genetic testing, its accuracy and availability, there is a definite increase in seeking out health-conscious breeding and actively selecting dogs or cats free from predictable genetic disease.”
Genetic testing can also determine which breeds exist in a dog.
Some companies take it one step further and also tests for genes controlling body conformation and known disease-causing mutations.” Other resources provide a list of testable disorders and treatments, most notably the WSAVA Canine and Feline Hereditary Disease Test Database hosted on the PennGen website at the University of Pennsylvania School of Veterinary Medicine.
Recognizing the heritability of common illnesses like allergies and some gastrointestinal diseases help veterinarians know that their patients are dealing with a life-long issue and not simply experiencing an episodic event.
It can be used for the prescription of preventative measures. For example, hip dysplasia is found in all dog breeds, and studies have found that it is 20% to 40% heritable. Veterinarians can gently palpate the hips of young dogs and determine whether or not they are lax and prescribe preventive measures accordingly. These can include maintaining lean body weight, avoidance of hip compaction activity prior to skeletal maturation and pre-emptive surgery in severe cases.
“In the 20 years since clinical genetic testing has been available in dogs and cats,” said Dr. Bell, “over 150 mutations have been identified for genetic disorders, and we can now predict occurrences and intervene to prevent or lessen its effect in many of our patients.”