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
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.
Q: So some breeds are more prone to cancers? Are mixed-breed dogs less
likely to get cancer?
A: Any time you have an inbred population, you don’t know what else is being
inherited along with the traits you want. People like golden retrievers because
they look like golden retrievers. But what else is being passed through that
line? Golden retrievers have a strong incidence of cancer. So do boxers,
flat-coated retrievers, Bernese Mountain dogs. All of those breeds, and others,
have specific cancers that we see. That’s showing that there are probably
specific genetic components to some cancers. But it’s still a question of how
much is genetics versus environmental factors.