Information provided by https://pets.webmd.com/dogs/guide/dogs-and-cancer-get-the-facts#1*
Cancer is the leading cause of death in dogs over the age of 10. But half of all cancers are curable if caught early, experts say. WebMD talked to Dave Ruslander, a veterinary oncologist and past president of the Veterinary Cancer Society, about canine cancers and the latest treatments for dogs diagnosed with the disease.
Q: How common is cancer in dogs, and what are some of the common cancers found in dogs?
A: 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.
Q: 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.
Q: What can I do to help prevent my dog from getting cancer?
A: The biggest thing is spaying your dog. If you spay a dog before its first heat you’ll reduce the chance of mammary cancer eight-fold, just because of the hormonal influence.
Good oral care can help decrease oral cancers. And if you’re buying a purebred dog, check its line to see if there’s a specific kind of cancer in that breed’s line.
But overall, prevention is difficult because we don’t know the causes of most cancers. I think, rather than trying to prevent cancer, identifying it early and treating it quickly is the better strategy.