Blood & Mucus in Dog Stool: Causes, Treatments & Emergencies

The look, consistency, and shape of blood and mucus in dog stool is helpful for your veterinarian to diagnose what's wrong, but it's never something to ignore.

Updated January 25, 2024
Child with an Ashamed Dog in a Garden

Finding blood and mucus in your dog's stool usually means that they have some sort of infection, parasite, or other health condition. Although you should always talk to your veterinarian if a situation like this arises, it's helpful to understand what can cause this problem and how you and your veterinarian can work together to help your dog feel better. 

Possible Causes for Mucus and Blood in Dog Stool

It is natural to be concerned if your dog is pooping bloody mucus, but the reality is that there are many potential causes. While blood and mucus in your dog's stool might occur because they just passed something that irritated their colon, there are several other potential reasons.

Worm Infestations

Most dogs will contract a case of worms at some point in their lives. Whipwormshookworms, and tapeworms are all intestinal parasites that can cause bleeding or mucus in stools. 

Irritable Bowel Disease (IBD)

Also referred to as colitis, IBD is caused by irritation and inflammation in the large intestine, and it can produce both blood and mucus in your dog's stools. Irritable bowel disease can lead to a yellow-colored mucus on the stool. The disease can be brought on by other primary causes, such as worm infestations, stress, or a change in diet.

Chronic Diarrhea

Chronic diarrhea is a long-term condition that is often accompanied by blood and mucus. It's caused by a number of health issues, including intestinal blockages, parasitic and viral infections, cancer, pancreatic disease, and more. This makes it difficult to narrow down the exact cause of the diarrhea, which is why speaking to your veterinarian is so crucial.

Fast Fact

Mucus in dog diarrhea can also indicate a negative reaction to something the dog ate or a result of a change in diet, stress, or inflammatory bowel disease


Parvovirus attacks the lining of the gastrointestinal tract and produces large amounts of diarrhea loaded with blood and mucus. The canine distemper virus, which is another life-threatening virus that puppies are often vaccinated against, can affect the gastrointestinal tract and cause bloody diarrhea. Finally, canine coronavirus also produces blood in stool, but there is a distinct lack of mucus with this particular virus. Your veterinarian will work with you to rule out these serious diseases quickly, while providing supportive care so your dog doesn't become dehydrated.

 Dog lying on sofa at home, looking ill and sad


Giardiasis is a condition caused by a single-celled organism that invades a dog's intestines. It produces chronic diarrhea and stools filled with fatty mucus. Similarly, coccidia can cause the same symptoms. 

Foreign Body Bowel Obstruction

Dogs tend to eat a lot of things they shouldn't, and any object that can't be digested in the digestive system has an opportunity to cause a blockage in the stomach or intestines. This is a medical emergency and usually needs surgery to resolve.

Straining and irritation can lead to bloody stools as well as mucus that is produced as a reaction to the irritation. A foreign obstruction can also lead to an infection that will produce yellow mucus in the dog's stool. 

Colon Cancer

Colon cancer can present some of the same symptoms as IBS, so it is sometimes overlooked when searching for the cause of bloody mucus in dog stool. Watch for weight loss in addition to blood in the stool, which can indicate the presence of cancer.

Liver Disease

Liver disease affects the production of proteins that support blood clotting and may lead to blood being present in stool. It's also possible to mistake bleeding caused by liver disease for a bleeding ulcer, which can often produce dark, tarry stools.

Dog Poop Like Jelly With Blood

Dogs suffering from acute hemorrhagic diarrhea syndrome (AHDS), which was previously called hemorrhagic gastroenteritis (HGE), produce stool that's often described as looking like it's coated in strawberry or raspberry jelly. Acute hemorrhagic diarrhea syndrome may be caused by stress, bacteria, or your dog eating things they shouldn't have.

A dog with AHDS should be taken to the veterinarian right away for treatment. The good news is it can often be treated with hydration by administering an IV or subcutaneous fluids, antibiotics, vet-approved bland diets, and plasma transfusions in severe cases. But if left untreated, AHDS can be fatal. 

Need to Know

If your dog's poop looks like red jelly, chances are they're producing diarrhea from acute hemorrhagic diarrhea syndrome and need veterinary care. 

Hematochezia Versus Melena

The color and consistency of the blood in the stool can help your vet determine whether the blood originated in the upper or lower portion of the digestive system. This information helps them form an accurate diagnosis and treatment plan.


According to the Handbook of Small Animal Practice, hematochezia is the term used to describe the presence of fresh, red blood in the stool. This means the source of the bleeding must come from somewhere in the lower gastrointestinal tract. Hematochezia may be an indication of a serious health problem, or it could be something very minor.

  • If the bleeding happens only one time and your dog is still eating, not vomiting, and otherwise seems to be fine, it is considered a transient event and is usually nothing to worry about.
  • If the bleeding continues, worsens, recurs, or is accompanied by other signs of sickness, take the dog to a veterinarian to determine the cause.

Some of the more common causes include:

  • Infectious agents
  • Bacterial infections, including salmonella and clostridium
  • Colitis or proctitis
  • Overeating, eating food that has gone bad, or eating bones and other jagged or sharp foreign material
  • Allergies to certain foods
  • Cancerous tumors or benign polyps in the rectum, colon, or anus
  • Bleeding disorders that affect clotting 
  • Inflammation of the anal sacs
  • Injuries and trauma, such as a fractured pelvis 


Melena is the term used to describe digested blood, which are shiny, sticky, and black. They have the consistency of tar and smell very foul or sometimes look like coffee grounds. This appearance indicates that the blood passed through the dog's upper digestive system before being passed in their stool. 

There are many causes of melena, and most of them are very serious. The first thing your veterinarian will do is rule out the possibility of the digested blood coming from a wound the dog was licking or from swallowing blood originating in the dog's respiratory tract or mouth.

Some of the most common causes of melena include:

  • Gastrointestinal tract diseases causing ulcerations and bleeding
  • Clotting abnormalities and bleeding disorders
  • Drugs, such as combinging nonsteroidal anti-inflammatory agents and corticosteroids which can ulceration of the intestine
  • Tumors in the gastrointestinal tract
  • Twisting of the stomach
  • Severe infections
  • Addison's disease
  • Shock
  • Toxicity from heavy metal poisoning, including from arsenic, zinc, and lead

What You Should Do

It's never a good idea to ignore the presence of blood or mucus in your dog's stool because it can be caused by so many conditions that require treatment. If you find yourself in this situation:

  1. Collect a fresh sample of the stool in a Ziplock bag. Place it in your refrigerator to be kept fresh for up to 12 hours.
  2. Call your veterinarian, explain what's going on, and make an appointment to bring your dog in for an exam. 
  3. Your vet will perform a fecal examination of the stool sample to check for the presence of worm eggs, bacterial overgrowth, as well as any other clues to the cause of the stool's condition.
  4. The vet may decide to perform further tests based on the initial exam. Depending on your dog's symptoms, these may include an ultrasound or X-ray, bloodwork, urinalysis, colonoscopy, or any other tests deemed necessary to reach an accurate diagnosis.

Treatment Options

Once you've discovered your dog has blood in their stool, Dr. Megan Teiber, DVM, says, "It is helpful to withhold all food and treats for 12 to 24 hours to give (your dog's) system a break. Then feed a bland diet of plain, boiled chicken and white rice." She also suggests using probiotics "from a trusted brand that is made specifically for dogs."

She cautions strongly against home remedies for blood in a dog's stool, "I do not find many other over-the-counter products or home remedies to be effective. Some human anti-diarrheal medications can even be harmful to dogs. If the stool is not back to normal after 1 to 2 days, or if your dog is vomiting, not eating, or lethargic, you need to bring him to a veterinarian." 

Don't Panic

Resist the urge to panic. Many conditions that cause blood and mucus in stools are reasonably straightforward to treat, such as worms and giardiasis. Even cases of canine coronavirus can be managed if caught early. The key is to contact your vet right away before your dog's condition has a chance to deteriorate.

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Blood & Mucus in Dog Stool: Causes, Treatments & Emergencies