by Dr. Jessica Vogelsang | Featured on PetMD
This week, I received the happy word that the latest mass I had removed from Brody was benign. Given that he has already dealt with two big baddies—melanoma and mast cell tumor, the latter necessitating the amputation of his ear—this is a big deal. I’m not going to lie, I did a little happy dance.
I’m ever vigilant because Brody is a Golden Retriever, and 60 percent of Goldens die from cancer. All of mine have. And given that this percentage is higher in this breed than in the general canine population, it stands to reason that there is probably a genetic component in there that predisposes a dog to cancer.
Despite what the internet rumor mill will have you believe, cancer is complicated, and it’s going to take a lot more than feeding organic food to get to the root of the problem.
Fortunately for us, the Morris Animal Foundation is already on the case. The Golden Retriever Lifetime Study completed enrollment in 2015. This study, comprised of 3,000 Golden Retriever families who agreed to be part of the project for the life of the dog, aims to develop the most comprehensive set of data ever collected on a group of dogs. Having that data available will help to better understand the link between genetics and disease.
By starting the data collection from a young age, scientists will have a much more complete view of the factors contributing to the dog’s health. Owners complete intensive questionnaires, give samples of the dog’s blood, urine, and feces, and even have their home drinking water evaluated. Down the road, as the dogs get older and start to develop disease, there will be a complete set of data specific to that individual to help the study designers pinpoint what is going on.
The discussion of “hybrid vigor” has long been a contentious one in animal circles, the idea being that the inbreeding necessary to maintain a purebred line will make an animal more susceptible to genetic disease and therefore less healthy overall than mixed-breed dogs. While the reasoning makes sense if you think about it, the reality is a bit more nuanced.
A study published in the Journal of the American Veterinary Medical Association in 2013 evaluated 27,000 dogs with disorders known to have a genetic component: hemangiosarcoma, lymphoma, mast cell tumor, osteosarcoma, aortic stenosis, dilated cardiomyopathy, hypertrophic cardiomyopathy, mitral valve dysplasia, patent ductus arteriosus, ventricular septal defect, hyperadrenocorticism, hypoadrenocorticism, hypothyroidism, elbow dysplasia, hip dysplasia, intervertebral disk disease, patellar luxation, ruptured cranial cruciate ligament, atopy or allergic dermatitis, bloat, cataracts, epilepsy, lens luxation, and portosystemic shunt.
Of the 24 disorders, 13 of them showed equal expression in both purebred and mixed-breed dogs. Purebred dogs were more likely to have 10 of them, and mixed breed dogs were actually more likely to develop cranial cruciate ligament disease. So what does that mean?
Several things, the main one being that we still have a lot of work to do. The study writers concluded that the disorders common in both purebred and mixed breed dogs likely resulted from mutations earlier in the canine evolutionary history; so while there is still a genetic component, it is more equally spread among the canine genome.
While the 3,000 families enrolled in the study might not benefit directly from the information gleaned, their willingness to participate is very likely going to make a huge difference in the lives of others down the road—for Golden Retrievers, for all dogs, and even for people, since we share many of the same diseases.
Though this study has lots of implications for medicine as a whole and how we diagnose and treat disease in the future, it doesn’t change anything for individual pet owners in the here and now. Focus on your individual dog and be aware of possible problems, have masses evaluated and removed promptly, know your dog and don’t wait if something seems off.
The fight for a long and healthy life is taking place on many levels, and at the end of the day the little eyes peering up at you in your home are the only ones you need to worry about.
Oregon Veterinary Specialty Hospital (OVSH) has been serving the Portland and Beaverton area community since 1979. Drs. Steven F. Skinner (Neurology, Neurosurgery) and Robert T. Franklin (Internal medicine.) We welcome referrals from veterinarians all over the Pacific Northwest. Our goal is to help your pet regain health and live a long and happy life.
Oregon Veterinary Specialty Hospital
9339 SW Beaverton Hillsdale Hwy,
Beaverton, OR 97005.