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Blood in Dog Stool: Crisis Mode, or Wait-and-See?

You’re on a regular walk with your dog, and she stops to squat and poop. When you go to pick it up, you see red – literally. Is my dog pooping blood? Did she eat cranberries? What is going on? Your mind starts racing – is she bleeding inside? Is she OK? She seems normal and happy… what should I do?

As dog owners, we’ve become very familiar with what’s considered “normal” for our dog’s poop to look like. So when the alarm bells are sounding, something is definitely up. Good news – not all blood is a cause for the “code-red emergency vet” visit. Here are some tips for how to make the decision.

blood in stool crisis mode or wait and see go to the vet or wait it out?

There are two different types of blood in dog stool: hematochezia and melena. Hematochezia is fresh blood, occurring in the large intestine or rectum, which is why it is a bright red color. Hematochezia can be mixed into the dog stool itself or you could see a few solo blood droplets. This bright red blood may also be accompanied by mucus, either streaks or covering the poop. With this type of bleeding, the poop can range from soft and formed, to watery diarrhea.1,2   

Melena, on the other hand, is a dark, tarry blood that can appear jelly-like. This type of bleeding occurs in the upper gastrointestinal tract including the esophagus, stomach, and upper small intestine where it has had time to be digested in the large intestine, giving it the dark appearance. Typically, the poop is formed with no diarrhea if melena is present unless it is that whole jelly consistency. The poop can appear shiny and sticky as well with melena present.1,2

You are probably wondering, why is my dog pooping blood? The reasoning behind blood in your dog’s poop is because the lining in the gastrointestinal tract is allowing more substances to cross its’ barrier like various fluids, electrolytes, and blood. This allowance occurs due to some type of stressor, whether that be an infection, trauma, or allergy. Some common causes of blood in poop are listed below.1,2

Hematochezia (Bright Red Blood)

Melena (Dark and Tarry Blood)

Parasites: hookworms, whipworms, roundworms, coccidia, giardia

Parasites: hookworms, whipworms

Inflammatory diseases: IBD, IBS

Inflammatory diseases: IBD, IBS

Food Allergy

Clotting disorders





Anal sac infections/impactions, including streaking from anal fissures

Foreign bodies or trauma


Kidney failure



Hemorrhagic gastroenteritis

Addison’s disease


Liver disease




Hormonal imbalance


Reaction to anti-inflammatory medications - NSAIDS


Most of the causes for blood in dog stool involve an infection of some sort, but they can also have melena from non-steroidal anti-inflammatory drugs (NSAIDs). NSAIDs are prescribed to dogs for pain, inflammation, and fever relief.  Some common NSAIDs are: Dermamaxx®, Doxidyl®, Previcox®, Galliprant®, Onisior®, and Rimadyl®, amongst others.3 While these drugs can be great to relieve discomfort in dogs, they can cause vomiting, decreased appetite, and diarrhea. NSAIDs can become trapped in the stomach and irritate its lining due to their slightly acidic composition, directly causing side effects. NSAIDs can also block the action of prostaglandins, which are responsible for controlling fever, pain, and inflammation as well as protecting the stomach and intestinal wall linings. When less prostaglandins are produced, a dog’s digestive system is more susceptible to ulcers and other damage which causes bleeding and diarrhea3 As always, if you notice any side effect occurring after beginning use of any medications, please consult your veterinarian.

While seeing blood in your dog’s poop may be alarming, it’s not always a cause for an emergency vet visit. Always consult your veterinarian if you notice blood, or anything strange, in your dog’s stool for over 24 hours. Knowing what specific type of blood that you’re seeing and if it’s caused by the medication your pup is on can be extremely helpful when making the call to your vet, helping to eliminate other possibilities.


Still concerned? Submit a photo for a digital stool scan. Free, on-demand support. Anytime. 



  1. Moore, Lisa E. Digestive System: Introduction. Handbook of Small Animal Practice. Pages 293-294. 2008.
  2. Marks, Stanley L. Approach to Clinical Signs of Gastrointestinal Disease: Diarrhea. Canine and Feline Gastroenterology. Pages 99-108. 2013.