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My 20 lb dog accidentally took 50mg Benadryl. Is it an emergency?

Updated On September 23rd, 2025

I accidentally gave my 20 lb dog 50 mg of Benadryl. Will she be okay?

3 Answers

Most Helpful Answer

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Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on January 19th, 2017

Oh no! So this dose is over twice the recommended dose for a dog her weight. Unfortunately, the lethal dose for oral diphenhydramine (Benadryl) in dogs has not been studied, but it's believed the minimum needed could be as few as four tablets according to a study published in 2014 in the Canadian Veterinary Journal. It would be best for you to take your dog into the vet now to have vomiting induced. While it is only two tablets, because the lethal dose hasn't been determined, it's better to be safe than sorry. I would find a vet on call to see her now, or take her into an ER vet.

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    Answered By Dr. Melanie, BVSc MS

    Veterinarian

    Published on November 2nd, 2016

    No, it shouldn't have any adverse effects, but I would not recommend doing this again unless it is prescribed by your vet. It's never recommended to self treat your animal as you may accidentally do harm to your dog.

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    Answered By David Elbeze, DVM, MRCVS

    Veterinarian

    Published on August 26th, 2017

    Recommended dosage for Benadryl for dogs is between 2-4 mg/kg. you gave Colt just over 4mg/kg, as toxic doses are only seen with much higher amounts of Benadryl i would not be worried about it in this case.

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