Being cautious about methods used for cats' vaccinations


August 07, 1993|By Gina Spadafori | Gina Spadafori,McClatchy News Service

Could the feline leukemia vaccine that protects your pet from one deadly disease trigger another? Does a cat's rabies shot increase its chance of getting cancer? The answer to both questions, according to a recent study, is a qualified "yes."

"The incidence of post-vaccination tumors is estimated to be approximately one case for every 10,000 doses of feline leukemia virus or rabies virus vaccine," said veterinary epidemiologist Philip Kass of the University of California, Davis, School of Veterinary Medicine. "This study shows there is a problem, but it's a small one that will not affect most cats and most cat owners.

"The important point to make is that a cat is at far bigger risk from feline leukemia if not vaccinated than from cancer if vaccinated."

The two-year study drew information from close to 300 veterinary hospitals and from CVD Inc., a Sacramento-based veterinary diagnostics laboratory. Dr. Kass and his associates, veterinarians William Barnes and William Spangler, studied the connection between 345 cats diagnosed with malignant tumors and the vaccinations they'd received. The data supported a link between cancer and the feline leukemia and rabies vaccines, but not with other common feline vaccinations.

Vets and cat-lovers had long suspected a problem, but it wasn't until Pennsylvania-mandated rabies shots for cats -- a move accompanied by a rise in malignant tumors -- that veterinary researchers started looking seriously at the issue.

"In October of '91, two research pathologists at the University of Pennsylvania wrote a letter to the Journal of the American Veterinary Medical Association," said Dr. Kass. "As pathologists, they'd been seeing more of these kind of tumors and it seemed to coincide with the Pennsylvania law. Lots of the tumors involved vaccination sites."

Dr. Kass became interested when Dr. Spangler, director of the diagnostics lab, brought the problem to his attention. The results of the UCD study are in the current issue of the Journal of the AVMA. The article indicates, among other things, that no one brand of vaccine is at fault.

"We just don't know why some cats respond this way," said Dr. Kass. "I do know there's a lot of interest in getting at what's doing this, but it'll probably be years before we really know much."

In the meantime, said Dr. Kass, the best thing you could do for your cat is to have your veterinarian vary vaccination sites when giving multiple vaccinations, and carefully document vaccination history.

The worst thing you could do, he emphasized, is not have your pet vaccinated at all.

"The chance of a tumor is far less than the chance of feline leukemia," said Dr. Kass. "I realize that's not much consolation to the person who loses a cat, but it's important to keep things in perspective."


What would you do if at this very minute you had to rush your pet to the vet's? What would you do in the middle of the night?

If you don't know the answer, you'd better find out. It could be the difference between life and death. A friend of mine learned that recently.

She recently moved and had set out some snail bait to combat the army of snails and slugs in her new garden. "It didn't occur to me the dog would be interested in it," she said.

When the dog started staggering and shivering, my friend knew she needed help, but didn't know where to go. She hadn't been in town long enough to find a regular vet, much less an emergency clinic. She quickly found one in the phone book -- and got lost on the way there.

Despite it all, she got there in time to save the dog -- and now swears she'd never repeat her mistakes.

"You've got to know where the hospital is and how to get there," she said. "It's not the kind of thing to figure out in an emergency."

I couldn't have said it better.

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