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How to prevent dog vaccine reactions like swelling and itchiness?

Updated on September 23rd, 2025

Pet's info: Dog | Mixed Breed Medium (23 - 60lb) | Male | unneutered | 4 years and 2 months old | 48 lbs

My 4 year old medium sized dog develops serious swelling and itchiness all over his body after his vet injects him with the combo shot (vaccine used to provide immunity against multiple diseases). It's been 3 years and this happens every time we get him injected with this particular shot. Though I give him Avil 25 mg tablet after such reaction as prescribed by vet, he seems low for two or three days. I don't think this is good for my dog. Please tell me what should I do. Is there an alternative?

1 Answer

Most Helpful Answer

Andrea M. Brodie, DVM

Answered By Andrea M. Brodie, DVM

Veterinarian

Published on April 12th, 2018

Your dog should get an antihistamine before the vaccination. You should ask your vet about giving him a diphenhydramine , or chlorpheniramine injection about an hour before getting the vaccination. This should avoid the reaction or at least reduce the impact. Your veterinarian should have these injectables available.
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