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  • Writer's pictureJulian Romero

Understanding the Causes of Cancer in Dogs

Cancer in dogs is a significant health concern, mirroring the complexities of human cancer. Understanding the causes, prevention, and early detection methods is vital for every dog owner. This guide delves into the factors contributing to canine cancer and offers practical advice for managing your dog's health.

1. Genetic Predisposition:

Genetics greatly influence a dog's risk of developing cancer. According to AVMA's research, "purebred dogs as a group have a higher relative risk for cancer claims than non purebred dogs do, at 1.9 times the relative risk."

Certain breeds, such as Golden Retrievers and Boxers, are more susceptible to specific cancers. For instance, larger breeds tend to be prone to osteosarcoma (bone cancer). It's important to research breed-specific cancer risks and discuss these with a veterinarian. American Kennel Club offers a detailed breed-specific risk assessment.

According to the AVMA, "the three breeds for which the fewest cancer claims were filed were Pomeranians, Chihuahuas, and French Bulldogs." If working with cancer is of great concern to you, consider adopting a smaller-breed dog, like Pomeranians, to have a lower risk.

2. Environmental Factors:

Dogs exposed to environmental toxins, including secondhand smoke, pesticides, and household chemicals, may have a higher cancer risk. Limiting exposure to these elements is crucial.

The Environmental Working Group comments on the numerous hazards that dogs are exposed to that can be linked to developing diseases and cancers:

"A dog eating scraps from the floor may also swallow dirt and dust tracked in from the outdoors and contaminated with heavy metals and pesticides (Colt 2004, vom Lindern 2003). A flea collar can spew droplets of insecticide that can be lethal to cats (Linnett 2008). Dogs and cats often eat food processing and packaging chemicals that contaminate their food, day after day and year after year, resulting in cumulative exposures with unknown health risks (FDA CVM 2008b). Chew toys might contain plastic softeners, foam beds might be infused or coated with fire retardants and stain-proofing chemicals linked to cancer and birth defects, and plastic water bowls might leach hormone disruptors."

This serves as a caution for how we care for our pets. Be mindful of the quality of food they eat, what toys they play with, and where their water is coming from. Naturally, indoor dogs may face fewer of these environmental factors, but they still are at risk of toxin exposure through their diets and chew toys. Fresh foods, like Just Food for Dogs, are worth the investment to prevent cancer. The National Canine Cancer Foundation writes that many chew toys have formaldehyde, lead, BPA, and other toxins that have been linked to cancer. Toys, like ones made by P.L.A.Y., are safe, eco-friendly toys that “meet the same strict quality standards for manufacturing children’s toys.”

3. Age and Gender:

Cancer prevalence increases with age in dogs, and certain types are more common in either gender. For example, lymphoma is often seen in older dogs. Regular health screenings for senior dogs are advised. The American Veterinary Medical Association offers insights into age-related cancer risks.

4. Diet and Nutrition:

A balanced diet is key in cancer prevention. Obesity is linked to increased cancer risk. Tailoring your dog's diet to their specific needs is essential. Consult Pet Nutrition Alliance for dietary recommendations.

Rover provides a pet-approved list of subscription and fresh dog food that can prevent obesity and meet your dog's nutritional needs without exposing them to harmful ingredients.

5. Viral Infections:

Some viral infections, like the canine papillomavirus, can lead to cancer. Vaccinations and regular vet check-ups are vital for prevention. The American Animal Hospital Association provides vaccination guidelines.


By understanding the factors contributing to canine cancer, you can take proactive steps to protect your dog's health. Regular veterinary visits and a healthy lifestyle are crucial. For more information, the National Canine Cancer Foundation offers resources and support for owners of dogs with cancer.

Title: Early Detection of Cancer in Dogs: Key Signs to Watch For

Being vigilant about your dog's health is crucial for early cancer detection. Recognizing early signs can lead to more effective treatment.

  • Unexplained Weight Loss: Sudden weight loss, despite a normal diet, could indicate cancer.

  • Changes in Appetite: A sudden increase or decrease in appetite warrants veterinary attention.

  • Lameness or Movement Issues: Particularly relevant in potential bone cancer cases.

  • Lumps and Bumps: Any new growths should be checked by a vet.

  • Abnormal Discharges: Bleeding or discharge from any body part is a red flag.

  • Behavioral Changes: Lethargy, coughing, or breathing difficulties can indicate internal issues.

Prompt veterinary consultation for any concerns is key. For more information on signs and symptoms, visit the Veterinary Cancer Society.


Early detection and regular veterinary check-ups are vital. If you notice any unusual signs, consult a veterinarian immediately. For comprehensive information, the American Veterinary Medical Association is an excellent resource.


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