Boxer Dog Cancer: 7 Ways Owners Can Lower The Risk

Boxers are referred to by some vets as “cancer factories” but it’s not a foregone conclusion that your Boxer will develop this disease.

Enough is understood about the causes of cancer that owners can take steps to protect their dogs.

Boxer owners can avoid many known cancer risk factors if they:

  1. Feed a raw, natural canine diet (not kibble)
  2. Provide clean, fresh spring or properly filtered water (not tap water)
  3. Maintain a chemical-free home including no fragranced products
  4. Exercise Boxers in places not treated with lawncare chemicals or weedkillers
  5. Keep Boxers intact (at the very least avoid neutering/spaying until after 2 or 3 years of age)
  6. Replace chemical wormers/flea and tick preventatives with non-toxic alternatives
  7. Fast Boxers regularly

I am not a vet. This post is intended for general informational and educational purposes only. I encourage readers to see my full disclaimer. Boxer Dog Diaries is reader powered. I may receive a small commission, at no extra charge to you, if you make a purchase via links I share. Thank you for your support.

Do Boxers Get More Cancer Than Other Breeds?

According to a 20-year study of mortality in North American dogs, published in 2011, cancer is a leading cause of death for all dogs, regardless of breed.

Unfortunately, Boxers rank among the breeds with the highest risk of developing cancer.

Golden Retrievers and Boxers in the study died from cancer more than from any other disease, and at rates higher than most breeds.

This was consistent with several earlier studies.

Cancer was responsible for 40 per cent of the deaths recorded in the American Boxer Club’s 2012 Boxer Health Survey.

A five-year Swedish study of 350 000 dogs, published in 2005, found the death rate amongst Boxers due to tumors increased sharply after the age of six.

What Cancers Do Boxers Get?

The cancers most commonly seen in Boxers include:

  • Mast cell tumors (affecting immune system cells that regulate inflammation and allergic reactions)
  • Lymphoma (cancer involving white blood cells called lymphocytes)
  • Hemangiosarcoma (a type of bleeding tumor of the blood vessels, often in the spleen)
  • Brain cancer (more prevalent in brachycephalic or short-nosed breeds)
  • Melanoma (malignant skin cancer)
  • Osteosarcoma (bone cancer)

Causes Of Cancer In Boxer Dogs

From a veterinary point of view, the reasons Boxers develop cancer at a higher rate than many other breeds are not well understood.

The scientific literature does offer some clues.

Non-Hodgkin lymphoma in humans is associated with environmental chemical exposures.

A 2020 study published in the Journal of Veterinary Internal Medicine investigated lymphoma in Boxers.

It found Boxers with lymphoma were more likely than their healthy counterparts to live within 10 miles of a nuclear power plant and within 2 miles of a chemical supplier or crematorium.

Researchers concluded that their findings supported the hypothesis that exposures to environmental chemicals and industrial waste may contribute to lymphoma risk.

When it comes to brain tumors, professor of veterinary and comparative pathology Dr John Robertson told the Purina Pro Club that “Published data going back 30 to 40 years shows that brachycephalic breeds have more primary brain tumors than other breeds.

“Genetic factors may make these breeds more susceptible to environmental pollutants or radiation causing cancer, but we really have no data to support this hypothesis.”

In other words, while genetics might load the gun … it’s diet and lifestyle — via cumulative exposure to toxins — that pull the trigger.

How To Lower Your Boxer’s Chances Of Getting Cancer

The statistics on cancer rates in dogs are drawn from the general pet dog population.

This means the rates apply to pet dogs that overwhelmingly:

  • Are neutered/spayed
  • Eat kibble
  • Drink tap water
  • Ingest chemical wormers and flea and tick preventatives on a monthly basis
  • Live in households that use chemical cleaners and exercise in outdoor environments that are treated with herbicides, pesticides and lawncare chemicals

It’s a fair bet these dogs are rarely, if ever, fasted — a health-promoting practice which is something all wild dogs do as part of their normal eating pattern.

In other words, the average Boxer is exposed to not just one or two but MANY known risk factors for cancer.

It stands to reason that the more of these risk factors you can eliminate from your Boxer’s life, the better your dog’s chances of remaining healthy and cancer-free.

1. Feed A Fresh, Natural Canine Diet (No Kibble)

Kibble exposes your Boxer to ingestion of several known carcinogenic substances including:

  • Mycotoxins produced by molds
  • Glyphosate, the active ingredient in the weedkiller Roundup
  • PBDEs (chemicals uses as flame retardants)
  • PFCs (perfluorinated compounds used as stain repellants)


Molds grow in dry dog foods when stored in warm, humid areas (like most kitchens), including one called Aspergillus flavus.

This mold produces a byproduct, or mycotoxin, known as Aflatoxin B1, which is the most potent naturally-occurring carcinogenic substance known.

See Spot Live Longer author Steve Brown spent a career as a pet food formulator.

He says, “Some of the waste products of these molds (that grow in open bags of dry dog food) are increasingly being implicated as long term causes of cancer and other health problems in humans, poultry, pigs and other animals.

“Dogs are particularly susceptible to these toxins.”

Brown cites data from antimicrobial product makers, which shows that mold growth starts after just four days above 12 per cent moisture.

These molds are invisible to the human eye and most dogs can’t taste them.

According to Brown, “While some dogs have died shortly after eating mycotoxin-contaminated foods, mycotoxins kill most dogs slowly by suppressing the immune system and creating long-term health problems in all organs of the body.”


Glyphosate is the active ingredient in the omnipresent weedkiller Roundup.

It’s been classified as a “probable carcinogen” since 2010 by the World Health Organization and was banned in France in 2019.

But it’s still used around the world.

The US Food and Drug Administration Commissioner from 2009-2015, Margaret Hamburg, said glyphosate only causes cancer “when swallowed in small amounts over a long period of time” .. which is precisely what happens when you feed your dog kibble — unless it’s organic.

In 2015, scientists Anthony Samsel and Stephanie Seneff tested a sample of dog foods for glyphosate and found it in every pet food they analyzed.

Flame Retardants

In 2011 researchers at Indiana University found flame retardants known as PBDEs in the blood of pet dogs at five to ten times the concentrations found in humans.

They also found the PBDEs in the dogs’ kibble at levels much higher than in human-grade meat and poultry.

According to the Environmental Protection Authority, studies have shown PBDEs cause cancer.

Stain Repellants

Perfluorochemicals or PFCs are stain, water and grease repellants like those in Teflon and Gore-Tex products.

How does this relate to kibble?

The grease-proof linings of dog food packaging are suspected as a dietary source of PFCs in dogs.

The health benefits of feeding a fresh, raw, species-appropriate diet are numerous.

Add to those the avoidance of the carcinogens found in kibble.

You can further reduce your Boxer’s exposure to chemicals like glyphosate by sourcing organic meats wherever possible.

2. Provide Fresh Water (No Tap Water)

The Environmental Protection Agency regulates more than 90 contaminants that are legally allowed to be in tap water in small amounts, including several known carcinogens such as:

  • The weedkiller glyphosate, from agricultural runoff
  • Arsenic from agricultural and industrial runoff and erosion of natural deposits
  • Industrial runoff like benzene
  • Chemicals like vinyl chloride leached from PVC pipes
  • Radionuclides like uranium, beta particles and photon emitters from decay of natural and man-made deposits
  • By-products of drinking water disinfection process like bromate and TTHMs (total trihalomethanes)

While these “regulated contaminants” might be present at minute levels, over time the chronic exposure can take a toll on your dog’s body.

Humans consume beverages other than tap water, but for dogs this is their only drink — ingested every day of their lives.

Provide your Boxer with fresh spring water or invest in a proper water filter for your home.

3. Create A Chemical-Free Home

Indoor pollutants are even more of a threat to our dogs than ourselves, since dogs spend all day long at home, breathing that air.

The sources of indoor contaminants are manifold, including the flame retardants and stain repellants used in household goods like furniture and electronics.

They’re in the foam in your couch and bed mattress, the plastic casing of your television, the paint on your walls, even the materials your dog’s bed is made from.

Volatile Organic Compounds and other contaminants leach into the environment, accumulating in household dust.

According to magazine The Bark, “Many environmental health and veterinary experts believe that chronic exposure to synthetic industrial pollutants in house dust may be at least partially responsible for skyrocketing cancer rates in dogs..”

Add to this the chemicals sprayed on surfaces via household cleaners and fabric sprays, emitted from fragranced plugins and inhaled by your dog as he stands at your feet in the bathroom while you apply hair spray and perfume each morning.

Boxer owners concerned with minimizing their dogs’ (and their own) chemical exposures should use non-toxic cleaning products in the home like baking soda, lemon and vinegar.

A powerful way to eliminate the need for cleaning chemicals is to invest in a quality steam cleaner like the BISSELL Power Steamer which uses nothing but superheated water to deliver a cleaner result than you could with chemicals.

To filter the indoor air of dust and VOCs, install a quality air purifier with a HEPA filter like the Medify Air Purifier

Lastly, vacuum frequently.

A cordless stick vacuum like the Dyson Cyclone V10 Animal makes cleaning a breeze.

4. Exercise Your Boxer Away from Chemically-Treated Environments

Assume that public parks, sports fields and roadsides are treated with lawncare chemicals and weedkillers including Roundup, which contains the cancer-causing chemical glyphosate.

Your dog inhales these chemicals when he sniffs the grass and trees and absorbs them through his paw pads.

Avoid using these chemicals on your own property and if you have the option, exercise your Boxer in herbicide and pesticide-free environments — or at least vary your dog’s routine to offset exposure to these chemicals.

The beach, for instance, is generally a safer choice than the park, particularly if the grounds are well-maintained and cared for by a staff of gardeners.

Local governments don’t necessarily make their spraying schedules publicly available or erect signage, so it can be next to impossible to avoid freshly treated areas when walking your dog around the neighborhood.

Wash your Boxer’s paws when you get home, either in the shower or using a device like the popular Dexas MudBuster.

5. Keep Your Boxer Intact (Don’t Neuter/Spay)

A 2020 paper compiled neutering recommendations for 35 breeds including the Boxer.

Researchers analyzed animal hospital records, comparing the incidence of disease in neutered versus intact dogs with a special focus on several cancers.

They found male Boxers that were neutered and female Boxers that were spayed had more cancers than Boxers of both sexes that retained their sex organs.

The effect of neutering on a dog’s health is worse, the earlier it’s done.

The 2020 study found that neutering before the age of two significantly increased the incidence of cancer in Boxers.

The ovaries and testes are responsible for far more than reproduction.

These organs produce hormones that have a protective effect on overall health.

Neutering/spaying is known to increase the incidence of a large number of diseases in dogs.

These diseases include several types of cancer, such as:

  • Mast cell tumors
  • Lymphoma (lymphosarcoma)
  • Osteosarcoma (bone cancer, common in larger breeds with a poor prognosis)
  • Splenic and cardiac hemangiosarcoma (as much as 5 times more likely and has a high death rate)
  • Prostate adenocarcinoma (risk quadruples in neutered males)

Given Boxers are already at increased risk of developing several of these cancers, Boxers as a breed particularly benefit from remaining intact.

If you absolutely must neuter/spay your Boxer, wait as long as you possibly can.

Don’t even consider it before the age of two.

There are three conditions (one in females and two in males) that neutering completely eliminates.

They are:

  • Pyometra (“pus in the uterus”)
  • Testicular cancer (the risk of an intact dog developing this is less than one per cent)
  • Enlarged prostate (a non-cancerous hypertrophy)

The incidence of these three conditions is very low and all three are highly treatable — whereas the cancers increased by neutering are serious and difficult to treat.

6. Manage Parasites Naturally (Avoid Chemical Wormers And Flea/Tick Preventatives)

Those chews that some owners give their dogs every month are internal pesticides.

They kill fleas and parasitic worms because they are neurotoxic.

Because your dog is larger, he doesn’t drop dead immediately.

But over time, constant exposure to these chemicals contributes to the toxic load your dog’s body is carrying.

Understand how fleas, ticks, intestinal parasites and heartworm are transmitted and assess your dog’s risk.

Depending on where you live and your dog’s lifestyle, you may be giving these chemicals for no reason.

Heartworm, for instance, is transmitted by the bite of a mosquito that’s bitten a heartworm-positive dog.

The life cycle of the larvae is interrupted at low temperatures, making heartworm preventatives unnecessary in winter, even in areas where the parasite is endemic.

There are non-toxic ways to protect your Boxer from parasites.

You can do fecal counts to check for worms.

Beneficial nematodes are a natural way to treat the backyard for fleas.

Ticks can be checked for and removed.

A fresh, raw diet will decrease your Boxer’s susceptibility to all of the above.

7. Fast Your Dog Regularly

Throughout their evolution, dogs have fasted as a natural part of their lifestyle.

Feeding dogs every day is a human invention.

Wild dogs like wolves eat once or twice a week, less in times of scarcity.

The digestive rest provided by periods of fasting allows energy to be diverted to cellular repair and regeneration through a process called autophagy.

Fasting boosts the liver’s detoxification pathways, helping your dog to purify his system.

In the Dog Cancer Series documentary, Rodney Habib and integrative veterinarian Dr Karen Becker discuss fasting in dogs with Dr Thomas Seyfried, a leading academic researcher in treating cancer as a metabolic disease.

Dr Becker’s article on fasting (listed in the references below) is a must-read.

In it she quotes Dr Mercola, the physician behind Mercola Healthy Pets, the most-viewed pet health website in the world.

Dr Mercola says to owners who fear denying food to their dogs:

“Not only will they not die, if you fail to implement a fasting protocol, you will prematurely cut short their life. Guaranteed. No question about it. They were designed to fast and if you deny them that because you think somehow they’re hungry, you are going to prematurely kill them.”


The causes of cancer in dogs are multifactorial and complex.

However, it doesn’t take a veterinary degree to see that owners can lower the risk by eliminating as many as possible of the factors known to contribute to cancer.

These risk factors boil down to neutering and toxic exposures through food, water, home, environment and the use of chemical wormers and flea/tick preventatives.

Fasting is a natural and side effect-free way to further protect a Boxer against cancer by supporting the body’s in-built detoxification processes.


A Way of Life for Wild Canines, This Could Be A Godsend for Your Dog, Mercola Healthy Pets, Dr Karen Shaw Becker, May 27 2018

Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers and Urinary Incontinence, Benjamin L Hart et al, University of California, Davis, 7 July 2020

Bone tumors in a population of 400 000 insured Swedish dogs up to 10 y of age: incidence and survival, Agneta Egenvall et al, Canadian Journal of Veterinary Research, 2007

Genetic and environmental risk for lymphoma in boxer dogs, Kaitlyn Craun et al, Journal of Veterinary Internal Medicine, 15 July 2020

Georgia’s Story: Creating a Partnership to Advance Canine Cancer Research, American Boxer Charitable Foundation, Sherry Buchla, May 2015

Glyphosate: The Hidden Dog Food Ingredient That Can Harm Your Dog, Dee Blanco, Dogs Naturally Magazine, October 8 2020

Household Pollutants and Dogs: A few sticky points, Susan McGrath, The Bark, Updated November 2017

Mortality in North American Dogs from 1984 to 2004: An Investigation into Age-, Size-, and Breed-Related Causes of Death, J M Fleming et al, Journal of Veterinary Internal Medicine, 25 February 2011

Mortality in over 350 000 insured Swedish Dogs from 1995 – 2000: II Breed-specific age and survival patterns and relative risk for causes of death, Acta Vet Scand 2005

Researchers Aim To Better Understand Brain Tumors in Boxers, Purina Pro Club, June 2008

Flame Retardants in the Serum of Pet Dogs and in Their Food, Marta Venier and Ronald A Hites, American Chemical Society, 2011

Long-Term Health Risks and Benefits Associated with Spay/Neuter in Dogs, Laura J Sanborn, Rutgers University, May 14, 2007

Study finds flame retardants in dogs, American Veterinary Medical Association, June 15 2011