Cancer and Pets: How Can We Prevent It?

While there is far more research performed for the benefit of humans than for pets, we know that much of the initial research into human disease and pharmaceuticals is performed using animals; therefore, we learn about them as a side effect.

In the veterinary field, many of the therapeutics we use to treat disease come from human medicine, at least initially. The treatment of cancer is no exception, and in fact, some cancer treatments derived from human medicine have worked well for animals. Others, however, have not.

It is important to remember that dogs and cats are not small people. While we do share much of the same physiology as our canine and feline counterparts, we do not share all of it.

It is likely that preventing cancer in dogs and cats will be similar to preventing any chronic illness and will involve addressing the following key factors: exercise, obesity, nutrition, stress and environmental pollutants.


Like humans, many pets simply do not move enough, resulting in stasis, or stuck energy. Cancer is one possible consequence of this sedentary lifestyle, though there are certainly many others.

Of course, disease processes are not that simple. Genetic predisposition also plays a role. This is why some animals that barely move their whole lives do not develop cancer, while some athletes do.

Stasis can be prevented by simply exercising your pet. The amount of exercise needed is tremendously variable, however, depending on the pet’s personality, age and energy level.

For dogs, regular, low-impact exercise like walking or swimming is ideal. Very active dogs may need additional exercise, like agility classes, flyball training or even just regular interactive play at home.

Don’t forget that cats need exercise, too. Figure out how your cat enjoys playing and set five to 15 minutes aside to play with him/her each day. Social activities with humans, such as playing with a laser pointer or feather teaser, provide great ways to get your cat moving.


A sedentary lifestyle and “overnutrition” create obesity.

Obesity sets up a host of hormonal and enzymatic changes that predispose the body to inflammation and immune changes. Chronic inflammation is very dangerous and, we suspect, can lead to cancer and other metabolic illnesses.

Of course, this is another area in which genetics plays a significant role, but there is no question that studies in both people and pets show that being moderately to severely overweight sets the stage for a variety of chronic diseases.

This can be a tough problem to fix as some breeds are prone to being overweight. Feeding for body condition — or assessing how the pet looks and feels — is the appropriate way to feed a pet from a young age.

Like many things, obesity is much easier to prevent than it is to treat. Treating an obese pet requires much more than simple caloric restriction; the metabolism needs to change through a combination of exercise and nutrition as well.

It is not easy, but it is doable. Start by learning how to score your pet’s body condition and do it on a regular basis.


Studies are currently being conducted to assess the role nutrition plays in the development of cancer. Because we do not have evidence-based data just yet, we rely on common sense and what we do know from the research that has already been done.

Our pets evolved in different parts of the world eating and scavenging different food items. There is no doubt that their bodies are changing and adapting to eat what most of us currently feed. Pet nutrition has come a long way, but given the rates of cancer and chronic disease, we still have a lot to learn.

We know cats are obligate carnivores and derive most of their moisture from their food. Ideally, our indoor house cats should eat food that mimics the makeup of a rodent. While dry food contains adequate nutrients, a good portion of a cat’s diet should really come from wet food. To say that this will prevent cancer is a stretch, but we do know that many chronic illnesses in cats may be prevented or improved by canned food diets.

Dogs evolved as scavengers and can eat a wide range of food items. Some breeds seem to require more protein than others, while some can thrive on carbohydrate-rich diets. Many do better on minimally processed diets. Some benefit from having their diet enriched with whole foods, like cooked vegetables. A few don’t.

The truth is, every veterinarian can tell you stories of how a diet change miraculously fixed a patient and sometimes, it was the tenth diet change that did it. We have all seen diet improve health as well as worsen it.

Feeding is individual and takes awareness and attention for our pets just as it does for ourselves. Ideally, we should all be feeding for disease prevention and that looks different in different individuals.


Does stress play a role in chronic disease development for pets as it does in people? Most likely, but stress looks much different for animals than it does for humans.

It may look like a cat that stops interacting with the family, sleeps 22 hours per day or urinates on anything left on the floor. Cats are intelligent, inquisitive and athletic animals. We keep them in the house to protect them, but we must give them things to do or they become stressed and shut down.

Cats need to climb, scratch and play. They also need adequate resources in multiple cat homes, as they are a species that is especially sensitive to social pressure. Environmental enrichment is key for healthy indoor cats.

Dogs have many different behavioral manifestations of stress from separation anxiety to excessive barking. Like everything else, genetics also plays a role in stress. In addition, we know that most dogs like to have a structured environment so they know what to expect.

Teaching dogs the rules of the house from an early age and dealing with behavior concerns builds confidence and helps them to be successful. Exercise is also tremendously stress-relieving to most dogs. For some, this can be as simple as regular one-on-one interaction with a favorite person.

Most of us know what makes our pets happy and providing that regularly can help them cope, but brainstorming ways that will actually work for your and your family, as well as your pet, may require professional assistance. A veterinary behaviorist or trainer can help you and your pet work through any problems and relieve chronic stress.

Environmental pollutants

While some environmental pollutants are unavoidable, we do have control over some, like cigarette smoke and insecticides, and limiting our pets’ exposure to both seems like common sense.

Fortunately, the topical insecticides that have been used for flea prevention have improved, though long-term studies have not been done in all of them. It is important to note that intermittent use of topical flea products is unlikely to be harmful and is certainly less stressful than suffering from chronic skin inflammation and itchiness. It is a balance that we have to judge for our own pets and should be discussed with a veterinarian.

There are many unchangeable genetic components that predispose our pets to chronic illness and cancer. Unless we know a pet’s lineage, however, we usually do not even know about this component. We can only do what we can by paying attention to the factors we have control over.

We can do our best to keep our pets lean and active. We can provide food based on what makes our individual pet thrive. We can take notice of behavioral changes that may indicate illness or stress and address them as they arise. And most of all, we can love our pets and give them attention and appreciate how they benefit our lives.

If you'd like to learn more about how to maintain optimal wellness in your dog or cat to prevent cancer, or if you suspect your pet has cancer, call your vet right away. Don't have one yet? We can help you find a local veterinarian

Contributing DVM