You may have noticed that some types of cancers tend to run in the family. This may be because family members share similar lifestyles. Maybe smoking or obesity runs in the family, predisposing a parent and his or her children to cancer. Or maybe abnormal genes are passed from generation to generation, as in the case of hereditary cancers.
Pets and humans suffer from the same kinds of cancers, though the most common types in each will differ. While the causes of most cancers are multifactorial, there is a genetic component to some cancers in pets just as there is in humans. Scientists are very interested in the genetics of cancer, because finding the genes that lead to cancer may also lead to a cure. In 2005, the entire genome of the dog was mapped, making the dog a perfect model for studying the role of genes in cancer.
About half of dogs over the age of ten years will develop cancer, and a quarter of all dogs will have some type of cancer in their lifetime. While both purebred dogs and mixed breed dogs can get cancer, we cannot deny that purebred dogs seem to bear the brunt of cancer woes. When we breed a dog to look and act a specific way, we restrict their genetic variability, and therefore inevitably introduce genetic diseases. In the same way that some dog breeds are prone to hip dysplasia or cataracts, some breeds are prone to cancer.
Golden Retrievers are one of the most favored of dogs in this country, but sadly, they are one of the top breeds to develop cancer, especially lymphoma. Many breeds have particular cancers; German Shepherds get hemangiosarcomas, Great Danes, Rottweilers and Greyhounds get osteosarcomas, Boxers get mast cell tumors, and Bernese Mountain Dogs get malignant histiocytosis. I could go on and on. But just as you might accept the fact that Dachshunds are prone to bad backs, you also have to accept that your purebred dog may be predisposed to cancer simply because of genetics.
Currently, there are ongoing projects searching for genes that cause cancer. Finding the genes that cause particular cancers will help scientists, who will also want to learn how common those genes are in other breeds. If genetic tests are developed, breeders can also use the information to pick and choose who they breed in an attempt to avoid passing on cancer genes to future generations. As if helping our best friends wasn’t enough, canine cancer studies can ultimately help humans in their fight for a cure.
One such study, the Golden Retriever Lifetime Study, run by the Morris Animal Foundation, is seeking to enroll 3,000 purebred Golden Retrievers between the ages of 6 months and 2 years in an effort to learn more about preventing and treating canine cancer. The study is featured in the upcoming “Work & Play” issue of fetch! magazine, due in homes Thanksgiving week.
If you’re not a Petplan policyholder, and you’d like to read more about the study, you can find fetch! magazine at your local Barnes & Noble bookseller.