What is melena?

Our question this week was:

Dr. Debra – my vet said my dog has melena, which means he is bleeding in his gastrointestinal tract. But his stool looks dark – not bloody. Is that right?


Janet B. – New York


Hi – thanks for your email. You wrote that your dog has melena. Melena is the presence of digested blood in the feces. It appears as black, tarry stool.

The fact that the blood is digested suggests that it came from high up in the gastrointestinal tract – such as the stomach. As it is digested – the blood appears as very dark black tar looking feces.

If the bleeding is from lower down in the gastrointestinal tract – then the blood can appear as fresh bright red.

There are many different causes for melena including gastric tumors or gastrointestinal ulcerations. A couple articles that might be helpful to you are Melena (Blood in Stool) in Dogs and Hematochezia (Blood in Stool) in Dogs.

Best of luck!

Dr. Debra

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