Are some dogs more likely to develop cancer than others?
Cancer can affect any dog, but some dogs have a higher risk than others. Just like factors such as age, sex, and family history can impact risk in humans, a dog’s age, breed, and overall health can play a role too. Understanding these risk factors can help you and your vet keep a closer eye on changes over time and decide what screening may be helpful.
Below are some factors that can increase a dog’s risk of developing cancer. This list doesn’t cover every possible risk, but it reflects patterns vets commonly see.
Age
Age is one of the biggest risk factors for cancer in dogs. As dogs get older, the immune system may have a harder time controlling abnormal cell growth. Exposure to environmental factors like pollutants and UV radiation from the sun over time can also play a role. Together, these changes can increase the likelihood of cancer developing.
The American Animal Hospital Association (AAHA) recommends that all dogs aged 7 and older (no matter the breed) have more frequent exams and testing. They may recommend blood, urine, or imaging tests to screen for health problems—they may also recommend specific tests to screen for certain cancers depending on your dog’s age and breed.
Breed
Some vets may recommend that certain types of dogs get yearly screenings at a younger age (around 4 years old) due to their particular breed. The following breeds have a higher risk of cancer:
- Beagle
- Bernese mountain dog
- Boston terrier
- Boxer
- Bullmastiff
- Chinese shar-pei
- Doberman pinscher
- English bulldog
- Flat-coated retriever
- French bulldog
- German shepherd
- Golden retriever
- Irish wolfhound
- Labrador retriever
- Miniature schnauzer
- Pembroke Welsh corgi
- Pug
- Rhodesian ridgeback
- Rottweiler
- Scottish deerhound
- Scottish terrier
- Siberian husky
- Weimaraner
Your dog's overall health
Age and breed aren't the only things that could increase a dog’s risk of cancer. Your vet will also consider your dog’s health history—including past illnesses, ongoing conditions, and any changes you’ve noticed at home.
If cancer is found earlier, it means you and your veterinarian can take action earlier.
How do vets screen dogs for cancer?
At a routine or annual checkup, vets will use a combination of methods to screen dogs for cancer and evaluate their overall health. Based on your dog’s history and what you’ve noticed at home, they may recommend different types of testing. These may include:
- Physical exam: Your vet will check your dog’s body for lumps, swelling, or other unusual changes. If they feel a tumor, bump or see other concerns during a hands-on exam that requires follow-up testing, they will talk you through what that may be and why.
- Routine blood and urine tests: These tests help give a clearer picture of your dog’s health from the inside. Abnormal results may prompt further tests, such as an ultrasound or X-ray.
- Cancer screening tests: Depending on your dog’s age, breed, medical history, and physical exam findings, your vet may recommend a cancer screening blood test. This test is designed to look for signals associated with certain types of cancers, like lymphoma. Until recently, veterinary blood tests for cancer weren’t available, so the disease often went undetected for longer. Although these tests can’t detect every type of cancer, these newer tests may help veterinarians diagnose certain types of cancers earlier, sometimes before there are noticeable signs. This may provide you with more time and options, such as confirmation of disease and starting treatment earlier.
- X-rays or other imaging: Vets sometimes use X-rays or other imaging to look at the internal organs, which helps them look for evidence of cancer. These scans can help find unusual lumps or changes in the lungs or belly that they can’t see or feel from the outside.
"Cancer Screening for Dogs: What Is It & Should You Do It?"
Learn how cancer screening in dogs works, what tests may be used, and when veterinarians may recommend screening based on age, breed, and health history.
Final thoughts
Cancer is a common health concern for dogs; understanding the risk factors and how your vet may look for cancer can help you care for your dog. Learning about cancer can feel overwhelming, but early detection and proactive care can help you and your veterinary team better manage your dog’s health and plan for the future.
Frequently asked questions
Frequently asked questions about this topic
Cancer may not cause any visible changes in the early stages. As the cancer progresses, you may notice weight loss, tiredness, vomiting, or limping, but these are not the only possible signs. Different cancers may show different symptoms.
While older dogs are more likely to develop most types of cancer, some cancers can affect younger dogs too. Ask your vet about your dog's specific risk factors.
Most vets recommend a complete physical exam every 6-12 months. During those exams, your vet may recommend tests to look for cancer and other health concerns, depending on your dog’s risk factors.
The most common types of cancer in dogs include:
- Lymphoma is a cancer of the lymphatic system and is one of the most common cancer in dogs.
- Mammary cancer, or breast cancer. About half of mammary tumors are cancerous. Some grow slowly, while others are more aggressive and tend to spread.
- Osteosarcoma is a type of bone cancer that’s most often seen in large-breed dogs. It usually causes tumors in the leg bones or, occasionally, other bones throughout the body.
- Mast cell tumors (MCTs) are the most common type of skin cancer in dogs. MCTs can look like small bumps or lumps and may change in size over time, but it’s important to know that not all bumps and lumps are cancerous.
- Hemangiosarcoma is a cancer that starts in blood vessels and most often affects the spleen or the area around the heart.
- Transitional cell carcinoma (urinary tract) starts in a dog’s bladder. It can cause ongoing urinary issues, such as urinary tract infections or bloody urine.
