August 25, 2016 – The most comprehensive study ever undertaken into hereditary disorders in dogs has found that one in every six dogs tested carried the genes for at least one of the inherited diseases or problems the researchers were looking for.
Moreover, one in six of the tested genetic variants was also discovered in a dog breed in which scientists had not previously known about and caused the same diseases.
“A striking example in our study is the identification of the lethal ataxia mutation (originally found in Finnish hounds) in Norbotten Spitzs. Breeders have been able now to utilise the information, panel test to stop the spread of the mutation and lethal disease in the breed. They can eradicate the mutation before it becomes a major problem,” said Dr Hannes Lohi from the University of Helsinki canine genetics research group, who was involved in the study in collaboration with Finnish company Genoscoper Ltd and researchers at the University of Pennsylvania.
The researchers found many canine inherited disorders are more widespread than previous studies had indicated, Dr Lohi said. And it is not only pure breed dogs who are predisposed to inheriting and passing on genetic diseases.
Photo by Petra Jaakonsaari: Dr Hannes Lohi with Reno the Great Dane at the Biomedicum Helsinki.
“Mixed breed dogs are likely to carry many of the same diseases as pure breeds,” Dr Lohi told Pet News Today, adding that the researchers are now planning to use their database of genetic information on 100,000 dogs to study and compare the incidences of genetic disorders between pure breeds and mixed breed dogs.
“Some canine disease mutations are old and widespread across a diversity of breeds, while others are more recent in origin and therefore limited to one or a few breeds.
“With the comprehensive screening we did, we were able to provide the most detailed picture yet of this distribution of disease mutations across breeds. The 34 breeds [in the study] had not previously been screened for such a wide selection of mutations, so no one knew that they also carried mutations originally found in another breed. This highlights how original mutation discovery studies are often based on a limited representation of the dog population, eg one or a few breeds,” he added.
The implications for dog health and welfare are significant. Genetic tests, such as the one Genoscoper Laboratories has developed for dogs MyDogDNA, enables dog owners, vets and breeders to test a dog for multiple inherited disorders.
“The challenge is to harness that potential for practical use in improved veterinary disease diagnostics, sustainable breeding selections, personalised pet care, and canine genetics research, said Dr Jonas Donner of Genoscoper.
“Pet care will greatly benefit from a diagnostic tool like ours that enables cost-efficient screening of multiple inherited disorders at once. Also, breeders will be able to make smarter breeding choices that promote puppy health.”
The study concluded that comprehensive screening for canine inherited disorders is an efficient and powerful diagnostic and research discovery tool that has a range of applications in veterinary care, disease research, and dog breeding. The study’s authors emphasised that the availability of complex DNA-based information is important for improving the health of pure breed dogs, but it should be utilised in combination with other established approaches that promote sustainable breeding and benefit breed health.
The published study provides also an excellent example of the added value of research collaborations between academia and industry in a form that leads to a powerful innovation that start changing the everyday practice in veterinary medicine and improves the welfare of our dogs, said Dr Lohi.
So would it be useful for dog owners to have their pet’s DNA tested? Dr Lohi said yes.
“You will know whether your dog carried any of the tested 100,000 plus disease mutations and has a risk to fall ill. You may find that your dog is sensitive to some drugs that your vet consequently needs to avoid. You would also benefit from knowing if your dog has an abnormal bleeding propensity before he/she is about to undergo surgery. In some cases, a genetic test will already enable selection of a type of special diet that helps in some conditions. You get everything with a single test without the need to send the samples to different laboratories with added costs,” Dr Lohi said.
“I wanted to develop something more useful for breeders and veterinarians. Most companies are still selling individual gene tests for each disease. I wanted to have them all combined for the same price. In addition, I wanted to have a test (MyDogDNA) that is not only about diseases, but also reports curiosity markers such as colour, fur type, size etc and measures the genetic diversity of your dogs and compares that information with the rest of the dogs in the breed.
“With all that, you can now combine a powerful strategy to avoid diseases and increase diversity for the health of the dogs in the breed. It all works very well in our MyDogDNA platform and has also a breeding tool that automatically compare your dog’s genome to the rest of the dogs in the breed (opposite sex) and rank them based on genetic difference or distance. You can then search best mates for future puppies to make sure they are genetically more viable,” he added.
Main photo: Serious eye problems are common in the Shiba Inu – cataracts, eyelash abnormalities, entropion, corneal dystrophy, persistent pupillary membranes, and progressive retinal atrophy (PRA).