But first, it’s important to define cancer. Cancer is a disease where cells grow out of control, invade surrounding tissue, and can spread (metastasize). Just like in humans, cancer can take many forms in dogs. The disease can be localized (in one area) or generalized (spread throughout the body). Cancer is considered multifactorial, which means it has no known single cause but heredity and the environment are thought to be factors.
How common is cancer in dogs, and what are some of the common cancers found in dogs?
It has gotten to be pretty common, especially in older dogs. Fifty percent of dogs over the age of 10 develop cancer at some point. We see malignant lymphoma, which is a tumor of the lymph nodes. We see mast cell tumors, which is a form of skin cancer. There are mammary gland tumors, or breast cancer, and soft tissue sarcomas. We also see a fair amount of bone cancer in dogs.
What are some of the symptoms of cancer in dogs?
A: The warning signs of cancer in dogs are very similar to that in people. A lump or a bump, a wound that doesn’t heal, any kind of swelling, enlarged lymph nodes, a lameness or swelling in the bone, abnormal bleeding. Those are all classic signs. But sometimes there are little or no signs, at least early on. So any time an animal isn’t feeling well, or there’s something abnormal or not quite right, the owner needs to bring it to the attention of their veterinarian.
Symptoms to Detect
The National Canine Cancer Foundation says there are 10 warning signs your dog might have cancer:
- Abnormal swellings that persist or continue to grow
- Sores that don’t heal
- Weight loss
- Loss of appetite
- Bleeding or discharge from any body opening
- Offensive odor
- Difficulty eating or swallowing
- Hesitation to exercise or loss of stamina
- Persistent lameness or stiffness
- Difficulty breathing, urinating, or defecating
If you find a lump or your dog has any of the other symptoms above, don’t delay in getting it investigated by your family veterinarian. If it’s confirmed your dog has cancer, it’s advised to get a second opinion — possibly by a board-certified veterinary oncologist — to discuss your options.
Some cancers can be cured with one or a combination of treatments, but sadly, many cannot and merely delay the inevitable. Some pet owners opt out of treatment completely and instead help their dogs with pain management (palliative care) throughout the course of the disease.
What’s causing these high cancer rates in our dogs?
People are taking better and better care of their animals and pets are living longer and longer, so we’re seeing more animals live to an age where they develop cancer.
Years past, many dogs died from common illnesses or were hit by a car. But now we have vaccines and we keep our dogs indoors, so they’re just around longer.
There also seems to be a genetic component in some cancers, because we’ve seen where some breeds seem more prone to cancers than others.
While not all cancers can be prevented, certain steps pet owners can take to help their dogs have a lower risk of developing it. For example, having your dog spayed or neutered at a young age can help prevent reproductive cancers. Some veterinary experts encourage giving your dog antioxidants in supplement forms like vitamins A, C, E, beta carotene, lycopene, and the mineral selenium to help ward off cancer. Healthy nutrition and exercise are also believed to help prevent cancer from developing.
The bottom line: Awareness of cancer symptoms and quick action are key to giving your dog the best chance for survival.