Should you be worried if your dog’s stool changes color?

Estimated Reading Time 3 minutes
Should you be worried if your dog’s stool changes color?

Monitoring your pet’s fecal material, including color, consistency, and frequency, are important parts of attentive pet care! Anything that’s abnormal for your dog should be noted. If it’s a recurrent issue, you should bring up your concerns to a veterinarian. Continue reading to learn more about poop color changes and other symptoms to monitor for and discuss with your vet!

Are you concerned about your pet?

Book a video consultation with an experienced veterinarian within minutes.

  • Professional vet advice online
  • Low-cost video vet consultations
  • Open 24 hours a day, 365 days a year

Abnormal Stool Color

If your dog’s stool suddenly becomes yellow, orange, green, or black, even if the consistency is normal, it’s time to make a note of the occurrence. If the abnormality occurs for more than 24 hours, there may be something going on that needs a trip to the vet to figure out.

Oftentimes, stool color change is due to something simple like a change in diet, treats that have food coloring added, eating colored Play-Doh (which can cause additional problems due to the salt content!), or drinking from algae infested locations (dirty fountains, ponds, etc.).

Yellow or Green Stools

Yellow to green colored stool can develop because the GI tract is upset and is moving things through too quickly. This rapid movement does not allow the body to absorb normal biliary pigments like usual and can cause the stool color to change.

Increased intestinal movement could be from eating something that upset the GI tract like a new treat or table food. However, intestinal parasites, small intestinal bacterial overgrowth, pancreatitis, liver shunts, Addison’s Disease, and exocrine pancreatic insufficiency can cause this to occur also.

Neon Blue or Bright Green Stool

Neon blue or bright green stool can be a sign of rodenticide (rodent poison) ingestion, and this can be life-threatening. The rat poisons are dyed bright blue/green in color, so it may look the same color as the rat bait itself. Rat bait poisons vary based on the brand, but many make it so the body cannot stop bleeding. This can be fatal if not caught early.

If you see any bright blue or green stool, consider it a potentially life-threatening emergency and go to the vet immediately. If you’ve recently set out rat bait, be sure to grab the box or container and bring it with you to the vet so they know exactly what your pet has been exposed to and direct appropriate treatment.

Red or Bloody Stool

Red or bloody stools are often from bleeds in the lower part of the intestinal tract. Parvovirus in puppies is a common cause of bloody diarrhea. Bloody stools could also be a sign of rodenticide ingestion and internal bleeding as a result of the toxin.

Black Stool

Black stools are typically an indicator of a bleed in the GI tract, often in the stomach or small intestines. There are some medications, like Pepto Bismol, or any other product containing Bismuth, that cause the stools to be black.

Should I take my dog to the vet if his stool is a weird color?

If your pet has been dealing with diarrhea or abnormal colored stools for more than 2-3 days in a row and no change in food or treats has been identified as the cause, it’s time to visit the vet for a medical work-up.

If your dog becomes lethargic, is eating less or not at all, is vomiting, or just doesn’t feel well, go to the vet right away. Always try to bring a sample of your pet’s feces with you so your vet can start testing it for parasites, bacterial counts, and possible viruses.

Read more:

Gastrointestinal Diets for Dogs and Cats

Parvovirus in Puppies: A Treatment and Prevention Q&A

Vomiting and Diarrhea in Dogs

Need to speak with a veterinarian regarding your dog's stool or another condition?

Click here to schedule a video consult to speak to one of our vets. You can also download the FirstVet app from the Apple App Store and Google Play Stores.

Published: 11/14/2020
Last updated: 10/29/2021

Are you concerned about your pet?

Book a video consultation with an experienced veterinarian within minutes.

Get started
  • Low-cost video vet consultations, 24 hours a day Low-cost video vet consultations, 24 hours a day
  • Experienced, licensed vets Experienced, licensed vets
  • Over 700,000 satisfied pet owners Over 700,000 satisfied pet owners
Low cost consultations, 24 hours a day.Low cost consultations, 24 hours a day.

With FirstVet, the vet clinic and pet shop are only one tap away. Get fast advice, trusted care and the right pet supplies – every day, all year round.


FirstVet Inc

900 3rd Ave 29th Floor


New York