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Why did my dog vomit after dewormer pills at one vet, but not another?

Updated on September 23rd, 2025

Pet's info: Dog | Mixed Breed | Male | unneutered | 20 lbs

The first 2x my dog took a deworm pill he threw up. In december he took another one, no side effects. Those 2 first times he was at a different vet (we dont go there anymore, as I didnt really like him :/), and the last time it was at his new vet. The first vet he went to also forgot to warn us that one of the vaccines needed a 2nd dose, the first one didnt even work and the new vet was the one who noticed this issue. What could have caused him to vomit at the other vet but not at the new one?

1 Answer

Most Helpful Answer

Answered By Daniel Fonza, DVM

Veterinarian

Published on April 22nd, 2019

It is possible that he could have been more stressed at the first visit or had car sickness causing him to throw up the first one. If a different dewormer was used, this could have caused it as well. As long as Max is ok now, that is all that matters. I've had countless dogs vomit with the dewormer. Some just have more of a sensitive stomach than others and it could have been that maybe Max had a more sensitive GI system at the time of the first dewormer but the GI system became more developed and not as sensitive at the time of the second dewormer. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further.

1Pet Parents found this answer helpful

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