Hard Lump in a Kitten's Right Leg From a Rabies Shot | The Nest — Pets

Hard Lump in a Kitten's Right Leg From a Rabies Shot

Hard Lump in a Kitten's Right Leg From a Rabies Shot
Dec 17, 2012
2 minute read

Rabies vaccines save lives, but that doesn't mean they are risk-free. There's a good chance your furry friend will develop a small bump or swelling near where he got his shot. Cats normally receive rabies vaccines in their right rear leg and a multipurpose shot on their front right shoulder.

Local Swelling

Vaccines aren't easy on your kitten's immune system. Their purpose is to challenge your pet's body into producing antibodies against future infection. Since pathogens are being injected during a vaccination, your kitty probably won't feel too great for the next few days. A small, hard swelling may appear where your kitty got his shot, but these nodules are painless and go away after a few weeks, according to Cornell University College of Veterinary Medicine. Other mild reactions include a slight fever, lack of appetite and sneezing for up to a week after the vaccination.

Allergic Reaction

Severe allergic reactions to a rabies vaccine are rare, but they can be pretty rough for your cat. Symptoms develop within a few hours, so you may notice something is wrong before you even get home from the vet. The area around the injection site may swell up during an allergic reaction. Your cat may be a little nauseous and his face may puff up a bit too, according to University of Illinois College of Veterinary Medicine. Contact your vet immediately if you notice any of these symptoms.

Sarcoma

You won't see a sarcoma right away. In fact, you may not even remember that your kitty had a shot where this new lump appeared. Sarcomas are tumors that develop directly under your kitty's skin and slowly expand. Sarcomas can appear weeks or months after the injection. While any vaccine can create a sarcoma, these unnatural growths are associated with the rabies and feline leukemia vaccines, according to University of Illinois College of Veterinary Medicine. They grow slowly to at least half an inch in diameter and persist indefinitely.

Advertisement

Diagnosis and Treatment

Taking your kitty to the vet in the event of a lump is always a safe bet. It will make you feel better to learn that it is just a harmless swelling, if that's the case. Treatment is only required in cases of allergic reactions or sarcoma. In the case of allergies, your vet will give your kitty something to stop the inflammation caused by his immune system. Smaller sarcomas can be surgically removed before there's a risk of the cancer spreading to other parts of your cat's body, but large ones may require amputation of the leg to stop the dangerous growth from spreading.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

Quentin Coleman

Quentin Coleman has written for various publications, including All Pet News and Safe to Work Australia. He spent more tan 10 years nursing kittens, treating sick animals and domesticating semi-feral cats for a local animal shelter. He…

Sponsored
The Nest — Pets Logo

Pets from The Nest — care guides, training tips and health advice for dogs, cats, birds and every other member of the family.

Property of TechnologyAdvice. © 2026 TechnologyAdvice. All Rights Reserved

Advertiser Disclosure: Some of the products that appear on this site are from companies from which TechnologyAdvice receives compensation. This compensation may impact how and where products appear on this site including, for example, the order in which they appear. TechnologyAdvice does not include all companies or all types of products available in the marketplace.