What is my dog’s risk for getting cancer?
Dogs and people develop cancer at about the same rate, with a lifetime risk being from about 1 in 2 to 1 in 3. Daunting odds – but this is due in part to increased longevity. Due to social, industrial, and medical advances, we and our dogs are simply living longer. Dogs in the wild have a life expectancy of 4-6 years, but domestic pet dogs have a life expectancy about twice that long. Because cancer is a disease that arises from mutations, more days alive means more cell divisions to maintain our bodies – and more chances to accumulate mutations.
Can I reduce my dog’s risk for getting cancer?
Certain environmental factors, like tobacco products, can speed up mutations that may lead to cancer. However, the main cause of mutations, known as mutagen, is the natural rate of errors that occur during the regular process of replicating DNA. There is no escaping the risk of cancer due to aging. Nevertheless, some factors that contribute to this risk might be altered. Cancer prevention research is an area of vigorous investigation that strives to figure out which factors can be modified to reduce risk and how they might be modified. One consistent finding is that lean body mass has a protective effect against cancer; this seems to be true in mice, monkeys, dogs – and people. In female dogs, spaying before the first heat is protective against mammary cancer; the incidence of mammary cancer in dogs spayed before their first heat is virtually zero, compared to about 10% (1 in 10) for intact females or females spayed after several heat cycles. Limiting opportunities for dogs to roam will not only protect against injury and death from fighting or being hit by cars but also will reduce exposure to transmissible venereal tumor (TVT) in areas where it is endemic (as in the southern border states).
What about feeding special diets and giving supplements as cancer preventatives or remedies?
Feeding a balanced diet, whether commercial or custom (as long as it contains all the necessary nutrients for growth, maintenance, and good health), in amounts that support a lean body mass is the only nutritional advice we can stand behind. We do not recommend adding any supplements to a balanced dog food diet except under the advice of a veterinarian (ideally, a veterinary nutritionist). Supplements are widely used by people in Europe, and while most do not cause harm (but also provide little or no benefit), there are plenty of medical reports that document some as toxic or as having otherwise bad health consequences. There are many products marketed in pet stores, in health food stores, and on the Internet that have not been rigorously tested for safety and/or efficacy. We caution people to be informed about any supplement or “alternative remedy” they give their pet, checking whether all the supplement’s ingredients are known and listed and whether it may interact with medications or other food the pet may routinely receive.
What is the purpose of clinical trials? Would a clinical trial improve my dog’s chances for survival?
Clinical trials are experiments, carried out in a clinical setting, that are meant to benefit the next generation of patients, not necessarily the participants. They test new ideas that were developed in the research lab. While all trials start with the intent of moving into the clinic treatments that will improve on the standard of care, their outcomes are unknown; some new treatments may be better than the best care available at present, but many will be only equally or even less effective. So, participation in a clinical trial carries unknown risks and uncertain outcomes. (For information regarding ongoing clinical trials at the University of Minnesota’s Clinical Investigation Center (CIC), click here.)
Are you looking for samples from my dog for your research?
Please see the Clinical Trials page for links to our current studies, including any that are actively looking for additional samples.