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’s causing these high cancer rates in our dogs?

A: I think 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.