Although cancer isn’t as common in cats
as it is in dogs, it still affects a number of our feline friends. And because
cats have a tendency to mask illnesses, it can be harder to detect. This often
leads to later diagnoses and more difficult and costly treatments. So we talked
to Dave Ruslander, a veterinary oncologist and past president of the Veterinary
Cancer Society, about feline cancers and the latest treatments for cats
diagnosed with the disease.
Q: How common is cancer in cats? What are some of the more common cancers
found in cats?
A: Cancer in cats is less common than cancer in dogs. It’s probably half the
rate that we see in dogs. But when we see cancer in cats, it tends to be a more
One of the most common cancers we see in cats is lymphoma, which is associated
with the feline leukemia virus (FeLV). Even
though there’s a vaccine for feline leukemia now, we still see a number of cats
that have been exposed to it, and exposure greatly increases a cat’s chance of
developing feline lymphoma.
We also see oral squamous carcinoma, similar to what people get. We see a tumor called fibrosarcoma, or soft tissue sarcoma,
which is a tumor developing in muscle or in the connective tissue of the body.
That’s the one associated with injections and vaccinations, which some people
call injection-site sarcoma.
We see other kinds of tumors as well, but they are much less common -- lung
tumors, brain tumors, nasal tumors, liver tumors. We don’t see as many mammary
tumors these days because so many people have their cats spayed now. So all
of those are just a smattering here and there.
Q: What are some of the symptoms of feline cancers?
A: Cats are tricky because they hide disease well. Externally we can see lumps and bumps. Vomiting and diarrhea are common signs of gastrointestinal lymphoma.
Difficulty in breathing can be a sign, because some cancers can cause fluid in
Sometimes it’s just a refusal to eat and weight loss, a rough coat, or just
generally what we call a failure to thrive. It’s always best, if your cat is
acting ill or lethargic for any period of time, to take it to your veterinarian
to be checked out.
Q: Is it difficult to diagnose the type of cancer a cat has
A: With a biopsy the pathologist can usually tell us the type of cancer. But
sometimes it’s not so clear. And sometimes people are reluctant to go forward
without a firm prognosis. Often we can’t go forward until we know what the
actual subtype is. It can take some special testing or some special stains for
us to delineate the type of cancer, and sometimes people just aren’t willing to