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Why is my dog's poop black and chalky/grey? Is it a serious issue?

Updated On September 23rd, 2025

Pet's info: Dog | Doberman Pinscher | Male | unneutered | 1 year and 3 months old | 55 lbs

My dad has been taking of my dogs while I’m away, but today I found their poop is somewhat chalky and some are black, so may I ask what does that mean? And if that’s a serious condition or maybe a sign of few things i have to take care of or avoide? Thank you!

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1 Answer

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Answered By Dr. Strydom, DVM

Veterinarian

Published on May 24th, 2019

Black stool in dogs may have a “tarry” or “sticky” consistency, which may be a sign of a gastrointestinal ulcer or a stomach ulcer. Many human medications can cause stomach ulcers in dogs, especially aspirin. Did your dad give the dogs any medications? If so, that would be an emergency to get them to the vet. The grey color indicates a diet that is high in calcium, raw bones and meat. Also a high fat diet. Were they given any of these things? I suggest you monitor them closely (and the stools) for the next day or so. If they are acting sick then get them to the vet for an exam. If not, just continue to monitor. If the stools don't return to normal then get them to the vet for an exam. For the next week or so feed them only their dog food and nothing else (not even treats) to keep their digestion stable. Hope this helps. Best wishes.

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