Can Vaccines cause a cat to get a tumor?

Question

Fel-O-Vax to be specific. My cat has sort of a oval shaped lump under her skin on her neck/shoulder. She got her shot about a week ago.

Answer 1

Cats can get tumors from any injection, look up feline injection site sarcoma... but this does not sound like such a tumor. Those tend to be cauliflower-like and grow out of the skin. They occur months to years after an injection, not in the same week. They're also very rare.

This sounds more like a localized vaccine reaction, both cats and dogs can have this happen from any vaccine. It should not be bothersome to the cat, and should go away in 1-2 months. Mention it to the vet before her next shots in case they want to do something a little different, but this is pretty common. If you're worried about injection site sarcomas (sometimes called vaccine-induced sarcoma), ask the vet to do your kitty's shots on the rear legs as far down as possible. This makes it easier to completely remove the tumor should one occur.

Keep a close eye on it though, and have the vet check it right away if it seems to be getting larger.

Vaccine adjuvant is a theory-it has not been proven to be associated with sarcoma. Some research suggests it's the physical trauma of the injection that causes it. We do, however, have the adjuvant-free rabies for cats available as an option to owners. Optional due to the price difference, we see a lot of barn cats and it's better to have them get a "cheap" vaccine than none at all. And ALL injections, no matter what is in them, are done on rear legs on our feline patients.

ANY animal can react to ANY vaccine at ANY time, regardless of brand or previous history. It happens. Individuals react differently.

Answer 2

Vaccines can cause tumors in cats but then so can any initiating in the skin. Two weeks is not enough time for a feline sarcoma to form it actually takes years. What you are seeing is likely a granulatoma. A injection site reaction that is the result of a poorly manufactured vaccine or a contaminated vaccine. A good vaccine will leave a very tiny lump, less than 1 mm and resolve within 1 to 3 days.

Answer 3

Chances are, the lump will disappear within the next couple of weeks. It's a normal bodily reaction to a foreign substance, the vaccine.

Fel-O-Vax is a line of feline vaccines made by Fort Dodge Labs. (Not the favorite manufacturer where I work -- if a vaccine is going to cause a problem, it is most likely to be a Fort Dodge product. They are the cheapest vaccines, so they're the ones used by most animal shelters, humane societiesd, rescue groups, and budget-minded vets. All vaccines are not the same quality.)

Here's the product information from the hand-out on Fel-O-Vax:

"Fort Dodge Animal Health's Fel-O-Vax combination vaccines are recommended for the vaccination of healthy cats as an aid in the prevention of important feline diseases.
Fel-O-Vax Lv-K® IV, our leading feline vaccine, provides protection against feline rhinotracheitis, feline panleukopenia, feline calicivirus, feline pneumonitis, and feline leukemia."

The vaccination that causes lumps to worry about is the rabies. In a small percentage of cats it, cancer develops at the site of the vaccination. There is a rabies vaccine from Merial Labs that is made especially for cats and does not contain the adjuvant associated with the cancers. It is about twice as expensive as the other rabies vaccines, so many vets don't use it. If I were you, if you have your cat vaccinated for rabies, I would ask which vaccine the vet intends to use. You may have to call around to find a vet who uses the Merial vaccine.

Any lump, on a cat, is a cause for concern, so if the one of your cat doesn't go away within a couple of weeks, have your vet check it.

Answer 4

I work at a vets office. It is normal for pets to get a lump after a vaccine. It should go away within 3 to 4 weeks. It is true cats can get a scarcoma (cancerous tumor) from a vaccine but that is very rare. If the lump is still there in a month, then get it checked. Scarcomas usually don't appear until much later. We constantly have worried pet owners coming in after vaccines to check lumps. They are normal.

Answer 5

Yes, they can. With today's vaccines and most brands, the odds are much better, but the lump is not normal. Get her back in to be checked. At the very least she is having a mild vaccine reaction and it should be noted in her medical record so that her vaccines can be separated in the future and they will know to watch her carefully, possibly even adding in an injection of benadryl with any future vaccines.

Answer 6

That sounds like an injection site sarcoma. Make an appointment to go back to the vet to have them check the spot this week--they need to be update on that! If it's caught early they can take it out before it causes more problems.

They'll likely do a needle biopsy first (large bore needle to check what's inside, they look at the cells). If it's just a fat deposit, it'll be left alone, but if it shows malignant cells, they'll take it out. My vet told me once that they see about 10 vaccination sarcoma for every 300 cats vaccinated. Definately don't wait too long on this.

I've not had lumps on any of ours (we have five) after they got their vaccinations. But I did have one react to the rabies vaccine once, loosing a palm sized area of fur within 1/2 hour of getting the shot. They had me bring him in twice in the next 2 weeks to check for sarcoma but he didn't develop that. Having a lump a full week after a shot isn't normal.

Answer 7

Yes,they can get sarcomas,but they will also sometimes get a local reaction to the vaccine,which will cause a lump.You need to take the cat to the vet see what it is.

Answer 8

yes they can if done in same spot,i looked this up 3 months ago as not sure to contine mine or not now,spoke to cats protection,who said they get theres done,but the people who work there and got own cats only get there cats done for first 2 years,then dont as they say they have anoth in there immunim system,and all the cats they had lived longer without

Answer 9

that is normal, i have five cats and they all get those lumps from any shot they have rabies, dystemper etc......dont worry, it goes away in about a month.............