These days, more and more pets are being diagnosed with cancer. In fact, 50% of all adult dogs will develop some type of cancer at some point, and one in five cats will be diagnosed with cancer in their lifetime.

Those are scary statistics.

Sometimes, due to genetic factors or predispositions we have no control over, our animals get cancer. But, knowing there are certain things that have been linked with, or suggested to cause, cancer, don’t you want to do all you can to try and reduce any risk these is? We know we do.

Even in our own homes, there are things we do or use that can actually increase the risk of cancer in dogs and cats. Knowing is sometimes half the battle, because once you know, you can make the changes that help your pet live the healthiest, longest life possible.

At Home Risks for Cancer in Dogs & Cats

Several things in and around our home environments can increase the risk of cancer in dogs and cats. By eliminating these things we can help reduce the chances, at least in part! And remember, if it isn’t good for our pets, it’s also not good for us!

1. Household Cleaners

Many household cleaners contain ingredients that are toxic to health, several of which are classified as carcinogenic, meaning they cause cancer. While things like bleach or ammonia are known to irritate the respiratory system, eyes, or nose, others can have far worse impacts. And that includes causing cancer in dogs and cats!

  • Formaldyhyde – found in many household cleaners and in laundry detergent because of its antibacterial properties. Beware, it doesn’t need to be listed on the label. Burning scented candles can also release formaldehyde into the air.
  • Phthalates – chemicals that give cleaning products their fresh, clean scent. Research shows that phthalates can cause liver, testicular, and pancreatic tumours in animals because they disrupt the hormonal system. These are found in all-purpose cleaners, dishwashing detergents, tile scrubs, disinfecting wipes, toilet-bowl cleaners, laundry detergent, and mold and mildew removers.

Ditch these! We have more on this below…

2. Second-hand Smoke

This one is a no-brainer. If second-hand smoke can cause cancer in humans, common sense would suggest the same for our animal friends. And research confirms it. Numerous studies show that the known carcinogens in second-hand smoke can accumulate in our pets’ bodily tissues, increasing the risk of cancer.

In dogs, this exposure has been linked to lung cancer, bladder cancer, and nasal adenocarcinoma. Cats exposed to second-hand smoke are at greater risk of developing lung cancer, as well as having a higher incidence of lymphoma (about 2 times more likely).

The course of action here is clear – no smoking around your pet!!

3. Flea and Tick Meds

Fleas and ticks are at the very least troublesome, and at the worst, harmful to health. But far too many pet parents douse their animals with chemical-filled flea and tick meds on a regular basis without understanding the impacts of this decision.

Not only has the FDA issued warnings to pet parents about the neurological dangers of topical flea and tick medicines, but research shows that many ingredients in popular topicals can cause cancer in dogs and cats. Permethrin, an insecticide in the pyrethroids family has been proven to be carcinogenic and cause liver tumors and lung cancer in animals, as has fipronil.

Flea collars present the same risk. Two dangerous pesticides- tetrachlorvinphos and propoxur – are common ingredients in flea and tick collars, and both have been linked to cancer:

  • Tetrachlorvinphos (TCVP) is an organophosphate pesticide and is toxic to the nervous system. Young children are particularly susceptible because their brains are still developing, and their ability to metabolize these chemicals is impaired relative to adults. In addition, TCVP is designated by EPA as a likely human carcinogen.
  • Propoxur is a chemical in the N-methyl carbamate class of insecticides, which is closely related to the organophosphates. In addition to its neurological toxicity, propoxur is a known human carcinogen. In August 2006, California added it to a list of chemicals known to the state to cause cancer.

Avoid these meds whenever possible, and opt for more natural alternatives to keep these pests off your pets. You can find several natural remedies and prevention tips at this post.

4. Outdoor Pesticides, Herbicides, Insecticides

Topical insecticices (flea and tick meds) aren’t the only issue. Pesticides and herbicides used outside are also a major concern. Such chemicals have been shown to have detrimental effects on all living things, and products such as pesticides and herbicides can inadvertently enter the bloodstream and increase the likelihood of cells changing and becoming cancerous. Exposure is often high in these cases, especially on newly spayed lawns and gardens.

For example:

  • Research shows an increased risk of malignant lymphoma associated with exposure to 2,4-dichlorophenoxyacetic acid (a common weed killer) in pet dogs.
  • Another study found that the use of professionally applied pesticides was associated with a 70% higher risk of canine malignant lymphoma.
  • Further research shows that exposure to herbicide-treated lawns has been associated with significantly higher bladder cancer risk in dogs, and that even dogs whose owners did not spray their lawns still had these chemicals in their urine from other areas.

While we can’t eliminate exposure completely to these toxic chemicals, stopping the use of them ourselves and educating others about the dangers they present can help reduce the risks of cancer in dogs and cats.

5. The Sun

Yes, the sun. And again, this one shouldn’t be a surprise because we all know about the risks of sun exposure and skin cancer. Solar radiation (i.e. sun bathing) increases the risk of hemangioma and hemangiosarcoma on the skin of dogs, especially those with a sparse or lightly colored hair coat.

Dogs need to spend time outdoors, and the sun definitely provides some benefits, but making sure our dogs have access to shade, and that those with shorter coats are not left in the blazing rays of the sun, can do a lot as far as reducing this risk.

Preventing Cancer

If there’s a way to reduce cancer in dogs and cats, we know you want to know about it. And again, while we can’t eliminate all causes of cancer from our pets’ lives, there are definitely several changes we can make to reduce the risk as much as possible.

1. Go Natural with Your Cleaning Routine

As mentioned, many chemical-based cleaners contain carcinogens, so it only makes sense to move to cleaning products that don’t contain these ingredients.

Numerous household items can be safely used for pet-friendly cleaning, including vinegar, baking soda, lemon juice, etc. In fact, we have a number of recipes for pet-safe cleaning at this post: Pet Friendly Cleaners for Your Whole Home: 5 Simple DIY Recipes. These recipes cover everything from floor cleaner to glass cleaner to toilet bowl cleaner. There’s even a pet-safe super scrub!

Don’t feel like making your own? We have a pet-friendly multi-purpose cleaning concentrate that you can trust won’t fill your home with harmful chemicals. Find it here.

2. When to Spay or Neuter

The decision to spay or neuter an animal can be a controversial one. There are researchers and veterinarians on both sides of the debate, and all in between the two ends of the spectrum. But one thing is clear – there is research that suggests that if and when an animal is spayed or neutered can impact the risk of cancer in dogs and cats.

For example, one study focusing on Golden Retrievers specifically found that:

  • Almost 10% of early-neutered males were diagnosed with lymphosarcoma, 3 times more than intact males.
  • The percentage of hemangiosarcoma cases in late-neutered females (about 8%) was 4 times more than intact and early-neutered females. 
  • There were no cases of mast cell tumors in intact females, but the occurrence was nearly 6% in late-neutered females. 

Another study looking at cancer in Rottweilers found that the risk for bone cancer was significantly influenced by age at spay/neuter. Male and female dogs who underwent surgery before 1 year of age had an approximate one in four lifetime risk for bone sarcoma and were significantly more likely to develop bone sarcoma than dogs who were sexually intact.

Additionally, prostate cancer in males is more common in neutered than intact dogs.

While it does seem to be that there are certain markers for different breeds, and different results, it pays to do your research. Before making the decision to spay or not, or at what age, make sure you read the research! Don’t just assume that spay/neuter, especially at a young age, is the way to go!

3. Keep Weight in Check

We know that obesity in pets is a growing issue, for a number of reasons. But there is also some suggestion that there’s a link between weight and cancer. While more research is needed, there are some studies that suggest weight may be a factor.

Part of this is thought to have something to do with fatty tissue in the body and hormone production. Fat tissue produces more hormones, and most breast cancers are very sensitive to hormones. Animals who are obese appear more prone to developing mast cell cancers, breast cancer, and bladder cancer.

  • Food – over-feeding, or feeding foods high in carbohydrates and sugars, can cause weight gain. A diet high in fresh food, including fruits and vegetables is important.
  • Exercise – all animals need some form of exercise. To burn calories and keep the body fit, your pet needs to move. Stay within your pet’s comfort level (based on breed, age, ability, etc.), but allow them the chance to work off the calories to keep weight down.
  • Stress – when an animal is stressed, the release of cortisol increases. Cortisol helps the body respond to a stressful event, but when stress becomes a chronic problem, cortisol also causes problems, such as weight gain and a weakened immune system. And if you’re limiting food to help your pet shed pounds, that alone can stress the body out! So make sure your weight loss plan considers this.

For more on helping your pet get to a healthy weight, read this next.

4. Feed Those Fruits and Veggies

We mentioned above the importance of feeding fresh foods to help your pet maintain a healthy weight, but it goes beyond that. There is much to suggest that a diet rich in fruits and vegetables can help decrease the risk of cancer in dogs.

First off, fruits and vegetables contain things called phytochemicals, many of which have been shown to help prevent cancer by blocking the effects of carcinogens. Many also contain high levels of antioxidants, which help to fight free radicals and oxidative stress, which can lead to cancer! Feeding foods containing these can help reduce the risk of cancer.

For example, one study found that dogs who ate vegetables at least 3 times a week had a lower risk (as high as 70%) of developing transitional cell carcinoma, noting that green leafy vegetables and yellow-orange vegetables had the greatest impact.

To help fight cancer, consider adding some (or all) of these to your pet’s diet on a rotating basis:

  • green leafy vegetables like kale, cabbage, and spinach
  • broccoli and cauliflower
  • berries, especially blueberries
  • apples
  • pumpkin and squash

As we see the instances of cancer in dogs and cats go up, we are lucky in that we know there are things we can do to at least minimize the risk in some way for our beloved animals. By making some very simple changes to our pets’ environments and lifestyles, we can hopefully help them live the longest, healthiest, happiest lives possible!