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My dog has sudden welts on his sides. Is it an allergic reaction?

Updated on September 23rd, 2025

Pet's info: Dog | Rhodesian Ridgeback | Male | neutered | 1 year and 2 months old | 70 lbs

My dog has welps all over his sides. It happened overnight. He's not itching and has been on the same food almost 3 months

1 Answer

Most Helpful Answer

Answered By Dr. Strydom, DVM

Veterinarian

Published on May 29th, 2017

Hello there. It sure looks like Wookie has some hives! He must be having an allergic reaction to something. I highly doubt it is food related. Food allergies are actually quite uncommon in dogs. It is more likely to be something in the environment or he got stung by an insect.

I would recommend you give him some Benadryl (diphenhydramine). NOT the non-drowsy kind. He is a big dog so he can have 3 capsules/tablets. Hide them in a small piece of hotdog or cheese or something he likes to eat. I know it sounds like a lot of medicine but dogs take a high dose as they metabolize it much faster than we do. It may make him sleepy but it usually doesn't.

If the hives are not gone in the morning or if you notice him have any trouble breathing, you need to take him to the vet right away.

I hope this helps. Best wishes to you and Wookie!

Dr. Amber

1Pet Parents found this answer helpful

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