Petco Text Logo
Petco Pet Logo
  • Two Easy Ways to Start Earning Rewards!

    rewards header
    Become a member today!
    Members-only pricing and offers, personalized care notifications, Vital Care points back on every purchase and more!
    Petco Pay LogoBecome a credit card member today!

    Earn 2X Pals Rewards points at Petco
    when you use Petco Pay!

    APPLY NOW
    Learn More About Petco Pay Benefits

Why is my dog vomiting and not eating after taking Novox and Flagyl?

Updated on September 23rd, 2025

Pet's info: Dog | Cavalier King Charles Spaniel | Male | neutered | 8 years and 7 months old | 23 lbs

Dog was prescribed Novox 25mg once a day for limping.This was on 1/9. On 1/12, work up & needed to go outside, where he was eating grass, bamboo, & other green plants to make himself vomit. Took him to the vet, who gave him a shot of Cerenia, & since diarrhea, one Flagyl 250 mg. Since then, about 9:00am, won't touch food & haven't seen him drink. Seems uncomfortable & if let out tries to eat grass.

1 Answer

Most Helpful Answer

Lotus Altholtz

Answered By Lotus Altholtz

Veterinarian, Board-Certified Lab Animal Medicine Specialist

Published on January 12th, 2019

It is possible that he is feeling nauseous from the Flagyl....that daily dose for a 23 lb dog is often split into two daily doses. It is also possible that he may have a stomach upset/or even an ulcer from the Novox, especially if it was given on an empty stomach. NSAIDs do have the potential of causing vomiting and diarrhea in sensitive dogs. A bland diet of boiled rice and chicken for 3-5 days plus a stomach coating medication called sucralfate daily for a few days +/- an antacid such as famotidine + subcutaneous fluids and bloodwork could be appropriate next steps. I’d recommend returning to your veterinarian or seeking a new vet if you are more comfortable with a new vet. Hopefully the lameness is no longer an issue and with relatively conservative management the vomiting and diarrhea can be resolved as well. Good luck!
Vote Icon1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Share

Styled arrow button