Dog Word of the Day: Hematochezia


In simple words, hematochezia is the medical term for blood in a dog’s stool. Dog owners who routinely observe their dogs’ daily outputs are at an advantage as they get to recognize signs of trouble such as diarrhea, the presence of parasites or fresh blood in the dog’s stool. The presence of hematochezia is often concerning for dog owners as they possibly associate the presence of blood in the dog’s stool with serious health conditions such as cancer. However, in dogs hematochezia is not always necessarily as troublesome, but it’s sure worthy of veterinary investigation so to identify the underlying cause and have it addressed.

blood-in-dog-stoolWhat Does Hematochezia Look Like?

Hematochezia in dogs appears as blood in the dog’s stool. Unlike melena, the blood is red, which means it’s fresh, frank blood that has not been digested. The blood may appear as streaks over the stool or mixed within it or there may be a few droplets of blood at the end of the bowel movement. Dogs owners often describe it as “my dog has bright blood in her poop” or “my dog passed blood clots in her stool.” The stool may be firm but it is often soft in consistency and may also appear as liquid diarrhea.

Where is the Blood Coming From?

While melena appears as dark, tarry stools, suggesting bleeding from the upper digestive tract, in hematochezia the presence of fresh, red blood is suggestive instead of bleeding in the lower intestinal tract. This means the blood may be coming from the dog’s descending colon or rectum. As mentioned, the presence of fresh, red blood in the dog’s stool can be frightening to witness, but in dogs it’s generally less frequently associated with life threatening diseases as those seen with melena, explains veterinarian W. Grant Guilford in the book “Textbook of Veterinary Internal Medicine. ” However, there are several conditions associated with blood in dog’s stools that can be worrisome.

What Does it Mean?vet

What causes hematochezia in dogs? Colitis, the inflammation of the dog’s colon is often a common culprit. Affected dogs typically have blood and mucus in the stool. Typically, the dog’s stools start off on the soft side and then become progressively gelatinous, shiny and with mucus, explains veterinarian Dr. Fiona. The mucus is produced by the colon when inflamed, while the blood is caused by erosions that trigger bleeding. Colitis is often seen with dietary indiscretions, abrupt food changes, presence of parasites or protozoans and even stress. In puppies, vomiting, diarrhea and bloody stools can be indicative of parvo virus which needs immediate veterinary attention. Other possibilities that require immediate veterinary attention include hemorrhagic gastroenteritis, blood clotting disorders and ingestion of rat poison.

Did you know? Dog owners often assume their dogs have hemorrhoids when they notice fresh blood on a dog’s stool. Dogs though don’t get hemorrhoids like humans do, but are more likely to get an impacted/infected anal glands, explains veterinarian Dr. Peter. These can sometimes be oozing bright red blood. Other possibilities are polyps in the dog’s colon or rectum, trauma to the anal area and sometimes cancer of the lower bowel.

What Should Dog Owners Do?dog pain goes away at the vet

Blood in a dog’s stool can be a minor, temporary problem or it could be a serious one that needs immediate veterinary attention such as parvo virus, a blood clotting disorder or ingestion of rat poison. It’s always best to play the “better safe than sorry” practice.

Blood in a dog’s stool is not normal and should be investigated by a veterinarian so that the underlying cause can be addressed. Bringing a stool sample along for the vet visit is a good starting point so that the vet can confirm or rule out presence of parasites or protozoans.

Disclaimer: this article is not meant to be used as a substitute for professional veterinary advice. If your dog has bloody stools, please see your vet for proper diagnosis and treatment.

DVM Greg Martinez Discusses Mucus and Red Blood in Stool



Textbook of Veterinary Internal Medicine, Saunders; 7 edition (January 7, 2010)

Photo Credits:

  • A vet examines a dog in New York, Archivist1174Own work, Photo of New York State Assemblyman Dr. Stephen M. “Steve” Katz at the Bronx Veterinary Center.CC BY-SA 3.0

Dog Word of the Day: Melena


In simple words, melena is the medical term for blood in a dog’s stool. Dog owners who are observant of their dog’s daily outputs are at an advantage as they can readily identify signs of trouble such as melena. Presence of melena can be a sign of some type of bleeding taking place in the dog’s upper digestive tract requiring immediate vet attention. It’s therefore important that dog owners learn how to recognize what melena looks like so they can report their findings to their vet and the vet can identify the underlying cause.

dog poopWhat Dog Melena in Dogs Look Like?

Melena is something that may be missed by dog owners because it’s not readily recognized unless dog owners are accustomed to seeing what their dog’ normal stools look like. Melena in dogs looks like jet black, tarry stools. Some dog owners describe it as “my dog has a burgundy color stool” or “my dog has black coffee ground stools or “my dog’s stools  look like dirt, tar or potting soil.”

The appearance of dark, tarry stools can be significant because it may be indicative of a sufficient large quantity of blood being lost from the body. The blackening of dog stool basically derives from a large volume of blood being digested. The black color is  due to oxidation of hemoglobin being altered by digestive chemicals.

It is generally the duration of passage of blood that determines the color more than location. For instance, in humans, it’s estimated that blood must be retained in the intestinal tract for at least 8 hours before it’s capable of turning the stools black.

dog pain goes away at the vetWhat Does it Mean When a Dog is Pooping Blood?

Dark stools aren’t necessary a sign of a particular problem. In some cases, a black tar-like stool in dogs may be simply due to something that the dog ingested (for instance, pepto-bismol,which is sometimes given under the guidance of a vet for a dog’s upset stomach, can cause a dog’s stool to become dark) and is therefore not a reflection of a condition a dog may have However, it’s important to have a dog checked out for dark, tar-like stools as it may be indicative of several disorders.

Generally, dark stools are a sign of bleeding in the upper digestive tract. The bleeding can therefore derive from the pharynx, esophagus, stomach or upper small intestine. Bleeding can be caused by presence of ulcers, cancers (leiomyoma and leiomyosarcom),  trauma, coagulation problems (disseminated intravascular coagulationexposure to rat poison.) Administration of non-steroidal anti-inflammatory drugs (Aspirin, Rimadyl, Previcox, Metacam, Deramaxx) or steroids(dexamethasone) can also be a culprit as these drugs may lead to ulcers, especially when used together or without a wash-out period. Dark, tarry stools in dogs may also be indicative of liver disease.

” Lots of dogs have dark stools and no problems or GI blood loss at all. The color of the stool is not an issue until the stool is pitch-tar-coal-asphalt black. Then it may be melena (if it is not due to Bismuth or a lot of green bile giving it a near-black appearance). If in doubt, just place some fresh feces on absorbent white paper and see if a reddish color diffuses out from the feces, confirming that there is blood present.” ~Dr. Michael Willard

What Should Dog Owners Do?vet

Upon noticing black, tarry stools, an important step would be to check the dog’s gums to make sure they are pink and that the color comes back quickly when you press on them (capillary refill time). Black, tarry stools may be a sign of significant bleeding in the digestive tract, and as such, the dog can become anemic. Pale gums or blue or gray colored gums and a slow capillary refill time are indicative of serious trouble and an emergency vet should be seen at once. Also, dogs acting lethargic and weak along with dark stools should receive immediate veterinary care.

Providing a sample of the dog’s black stool can provide an important piece of information. The vet can test the sample for occult blood, if in doubt. It’s also important to provide as much information as possible to the vet such as age of dog, what the dog eats, and any concomitant signs observed. For instance, a dog with dark stools who is also regurgitating may be suggestive of problems localized to the dog’s esophagus or pharynx. A dog with black stools who is also vomiting blood can be suggestive of stomach or duodenal bleeding. A dog with tarry stools and a yellow color of the gums may be suggestive of liver disease.  A dog who recently had a nosebleed can also develop black stools, but the nosebleed may be related to a coagulation problem and worthy of investigation.

A word of caution is always warranted: just because a dog doesn’t show signs of melena, doesn’t necessarily mean the dog is free of gastrointestinal blood loss. Bleeding can take place over time in small amounts that aren’t enough to cause the classical tar-like appearance associated with melena.

” Melena is not always seen in animals with chronic gastrointestinal blood loss since loss can occur in relatively small quantities over time.”~ Dr.Cathy E. Langston

Disclaimer: this article is not to be used as a substitute for professional veterinary advice. If your dog is sick or displaying any worrisome signs, please consult with your vet.



  • DVM360, GI blood loss: ulcer, erosions, and stuff that mimics them (Proceedings), retrieved from the web on July 27th, 2016
  • DVM360, Anemia of chronic kidney disease (Proceedings) retrieved from the web on July 27th, 2016
  • Textbook of Veterinary Internal Medicine,  Stephen J. Ettinger DVM DACVIM (Author), Edward C. Feldman DVM DACVIM Saunders; 7 edition (January 7, 2010)


Photo Credits

  • Flickr, Creative Commons, No pooping. Jeff Keyzer,  (CC BY-SA 2.0)
  • A vet examines a dog in New York, Archivist1174Own work, Photo of New York State Assemblyman Dr. Stephen M. “Steve” Katz at the Bronx Veterinary Center.CC BY-SA 3.0



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