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Dog's dark poop & low appetite after deworming: Is it a side effect?

Updated On September 23rd, 2025

Pet's info: Dog | American Pit Bull Terrier | Male | unneutered | 5 years and 8 months old | 65 lbs

hello i recently gave my adult dogs a dewormer and the last couple of days they have had a small appetite and their poop looks dark brown in color im kinda worrying is this temporary side effect or what Thanks for answering.

1 Answer

Most Helpful Answer

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Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on May 2nd, 2020

Thank you for contacting Petco Pet Education Center, formerly Petcoach with your question about Ace. This is likely a temporary side effect of the deworming treatment. It can cause some upset stomach, and the dark brown color of their poop may be normal. I'd just continue to monitor them for now. I hope this helps!

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