Blood and Mucus in Dog Stool

Updated August 4, 2021
Child with an Ashamed Dog in a Garden

The presence of blood and mucus in dog stool usually indicates some sort of infection, parasitic infestation, or other health condition. Although you should always consult your veterinarian if a situation like this arises, it's helpful to understand what can cause this problem and what you should do for your dog.

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. Blood and mucus in your dog's stool may be a natural occurrence, and your dog may be fine within 24 to 48 hours. Understanding the causes and symptoms can let you know when it's time to bring your dog to the veterinarian, but always give your veterinary office a call when you're unsure to keep your dog safe.

Worm Infestations

Most dogs will contract a case of worms at some point in their lives. Whipworms, tapeworms, and hookworms can all cause bleeding or mucus in stools.

Irritable Bowel Syndrome (IBS)

Also referred to as colitis, IBS 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 syndrome can lead to a yellow-colored mucus on the stool. The disease can be brought on by other primary causes, such as a whipworm infestation or a change in diet.

Dog golden poop

Chronic Diarrhea

Chronic diarrhea is a long-term condition that is often accompanied by blood and mucus. It is 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. Mucus in dog diarrhea can also indicate a negative reaction to something the dog ate or a result of a change in diet, irritable bowel syndrome, or inflammatory bowel disease.


Parvovirus attacks the lining of the gastrointestinal tract and produces large amounts of diarrhea loaded with blood and mucus. Canine coronavirus also produces blood in stool, but there is a distinct lack of mucus with this particular virus.


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.

Gastrointestinal Foreign Body Bowel Obstruction

Dogs tend to eat a lot of things they shouldn't, and any object that can't be dissolved in the digestive system has an opportunity to cause a blockage in the stomach or intestinal tract. 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.

Hematochezia and Melena

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


According to PetMD, hematochezia is the term used to describe the presence of fresh, red blood on 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, it is considered a transient event and is usually nothing to worry about. If the bleeding continues, becomes more severe, or keeps recurring, take the dog to a veterinarian to determine the cause.

Dog mess caused by colitis

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
  • Inflammation of the anal sacs
  • Injuries and trauma such as a fractured pelvis or a bite to the anal area


Melena is the term used to describe when a dog passes digested blood, which indicates that the blood passed through the dog's upper digestive system before being passed in stool. The stools are shiny, sticky, and black. They have the consistency of tar and smell very foul.

There are many causes of melena and most of them are very serious. The first thing your veterinarian must 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.

Melena dog stool

Some of the most common causes of melena include:

  • Gastrointestinal tract diseases causing ulcerations and bleeding
  • Clotting abnormalities and bleeding disorders
  • Drugs such as nonsteroidal anti-inflammatory agents and corticosteroids causing 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

Dog Poop Like Jelly With Blood

Dogs that suffer from Hemorrhagic Gastroenteritis (HGE) will produce stool that is often described as looking as though it is coated in strawberry or raspberry jelly. If your dog's poop looks like jelly with a reddish color, this means they are producing diarrhea from HGE that is mixed in with blood from the stomach and intestines. Hemorrhagic Gastroenteritis can be caused by stress or your dog eating things they shouldn't have. A dog with HGE should be taken to the veterinarian right away for treatment. The good news is, while it appears serious, it can often be treated fairly easily with hydration by administering an IV or subcutaneous fluids, antibiotics, and possibly a prescription diet or vet-approved bland home diet.

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 sample of the stool in a Ziplock bag.
  2. Call your vet, explain what's going on, and make an appointment to bring your dog in for an exam. If there is blood in your dog's stool but they are acting normally, your vet may recommend keeping an eye on them for 24 to 48 hours to see if they improve.
  3. Your vet will perform a fecal examination of the stool sample to check for the presence of worms or worm ova, 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, complete blood count, urinalysis, colonoscopy, or any other tests deemed necessary to reach an accurate diagnosis.

Before Your Veterinary Visit

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 easy to treat, such as worms and giardiasis. Even cases of parvo or canine coronavirus can be managed with early detection. The key is to contact your vet right away before your dog's condition has a chance to deteriorate.

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Blood and Mucus in Dog Stool