Injection (vaccine) site reaction - 6 mo old kitten?

Question

My kitten has a lump (slightly soft, movable, about the size of a quarter) where he had a shot about a week ago - we went to the vet this morning (they took a sample with a needle to check it) and were told it was a vaccine site reaction.

Right now i cannot recall which vaccine he had there (as it was only one that he had recently in that spot - i think it was his rabies vaccine) - but he is fully up to date -

What i was wondering is if anyone else had a cat who had a reaction to a vaccine like this and if there are any questions that i should ask the vet at his next appointment (we have another appointment next week where they are going to check the lump again and check up on his uti)

Does this mean he should not get more vaccines, or at least the type that he had the reaction to again? (he is an indoor only cat with one other cat in the household, also indoor only - both have been tested and are negative for ailments..)

thanks!

Kayty · Accepted Answer

A small number of cats do develop vaccine site reactions, and most commonly it is the rabies vaccination that the cat reacts to.

Vets give the immunizations in specific standard locations, to make it easier to determine if a lump is a vaccine site reaction and which vaccine caused it.  Your vet was being extra conscientious in also doing a fine needle biopsy to be sure what the lump was.   Lumps on cats are always a cause for concern.

When you see the vet next week, if he has decided that the lump is a reaction to the rabies vaccination, ask him who the manufacturer of the vaccine was.    In a small percentage of cats -- 3% to 5% -- skin cancer eventually develops from a rabies vaccination.    Merial Laboratories makes a rabies vaccine especially for cats which does not contain the adjuvant associated with feline skin cancers, but it is twice as expensive as other brands of the vaccine.   The vaccine manufactured by Fort Dodge is the most likely to cause reactions,  including skin cancer, but since it is the cheapest,  many shelters and "shot clinics" use it.

If your vet used a vaccine other than Merial, you should keep a very close eye on that lump and watch for any sign that is getting larger.   And I would ask your vet to use Merial rabies vaccine in the future.

Mercy · Answer

Rabies and feline leukemia vaccinations run a -- as I recall -- one in ten thousand risk of fibrosarcoma at the injection site, and that pops to mind when you mention a lump.  The fact that the lump occurred so soon after vaccination is actually good,  and there are other things that it could be.  But when your vet took a sample, he was taking a needle biopsy, and fibrosarcoma was what he was checking for, because it does happen  and must be dealt with immediately.  You should go online:

http://en.wikipedia.org/wiki/Vaccine-associated_sarcoma

This is going to frighten you, and I thought maybe I shouldn't respond.  But here I am doing this.

Anonymous · Answer

kittens sometimes have reactions like this to vaccines this is normal id just keep an eye on it and yes they still can get their shots there and usually rabies shots are given in the rear the others are given in the shoulder area if anything a vet will give a shot in a different area close to but not the same spot

puriena_puppy · Answer

There really is nothing to worry about, sometimes animals have a reaction to the vaccine and they get a small lump.  It will go away, usually takes a couple of weeks.  Doesn't hurt them.  Even though indoor ya should still keep vaccines up to date.

doxie · Answer

This happpens to my daughters cat eerytime he gets a vaccine. There have been no real problems he is not so playful on that day. We usually get his shots when some one is home, weekends or evening just in case but all has been fine.

Anonymous · Answer

Take him back to the vet.

Injection (vaccine) site reaction - 6 mo old kitten?

6 Answers