How do I know if my cat is having a reaction to a vaccine?

It’s not uncommon for a cat to have a reaction after receiving a shot. As you keep an eye on your pet’s condition and behavior, you may observe symptoms such as pain, redness and swelling at the injection site; a low fever; or a reduced appetite. These are generally mild reactions and rarely cause for alarm.

Serious reactions are unusual but not unheard of. If your recently-vaccinated cat suddenly has a seizure, exhibits unrelenting vomiting or diarrhea, or shows signs of acute distress, there’s no time to waste. Rush the animal to a veterinary hospital - your cat could be having a severe allergic reaction called anaphylactic shock. Quick action on your part could save your cat’s life.

– Dr. Larry McDaniel, DVM for the “Purina® Animal Instincts” Podcast Series

Source: www.purina.com