Dog Pooping Blood? Causes of Blood in Dog Stool and When to Worry

What Does Blood in Dog Poop Look Like?

Vets describe bloody stool by its color, because the color shows roughly where in the digestive tract the bleeding is coming from.¹

• Bright red blood (hematochezia): fresh red streaks or drops of blood on or in the stool. It usually comes from the lower digestive tract: the colon, rectum or anus.¹
• Black, tarry stool (melena): dark, sticky stool caused by blood that has been digested. It points to bleeding higher up, in the stomach or small intestine, and is often more serious. Some diets rich in organ meat can darken stool without any bleeding. Wiping the stool on a white paper towel can help: digested blood leaves a dark red or black residue.¹
• Blood and mucus (jelly-like stool): slimy, mucus-coated stool streaked with fresh blood is typical of colitis, inflammation of the large intestine. Dogs with colitis often strain and go more often, passing small amounts each time.³
• "Raspberry jam" diarrhea: sudden, large amounts of watery, bloody diarrhea are typical of acute hemorrhagic diarrhea syndrome and need urgent care.⁴

Take a photo and, if you can, bring a fresh sample to the vet. Note the color, consistency, how much blood there is and how often your dog is going.¹

Dog Pooping Blood but Acting Normal?

A dog that passes a small streak of fresh blood but is eating, drinking and playing normally is often dealing with irritation of the colon or rectum, for example after eating garbage, a sudden diet change, or straining to pass hard stool. Bright red blood is not necessarily a sign of a life-threatening illness, and mild colitis like this is a frequent reason for blood in otherwise normal-looking dogs.^1,3

Even so, call your vet for advice the same day. "Acting normal" does not rule out parasites such as whipworms, which can cause mucus and fresh blood without making a dog seem sick, or early stages of more serious problems.^5,1 Bring a stool sample so your vet can check for parasites, and go in sooner if the bleeding continues, gets heavier, or your dog develops any of the warning signs above.

Common Causes of Blood in Dog Stool

• Dietary indiscretion and sudden food changes: eating garbage, spoiled food, sticks or other non-food items can irritate the gut and cause bloody diarrhea.¹
• Colitis: inflammation of the large intestine causes mucus, fresh blood and straining. See our page on colitis in dogs.³
• Intestinal parasites: whipworms cause diarrhea "often streaked with mucus and fresh blood," and hookworms feed on blood and can cause dark, tarry stool and life-threatening anemia in puppies.^5,6 Learn more about hookworms, roundworms and other worms in dogs.
• Parvovirus: a highly contagious virus that causes severe, often bloody diarrhea, vomiting and lethargy, mainly in puppies and unvaccinated dogs.² See parvovirus in dogs.
• Acute hemorrhagic diarrhea syndrome (AHDS): sudden, profuse bloody diarrhea, formerly called hemorrhagic gastroenteritis (HGE). See the section below.⁴
• Anal gland problems: infected or impacted anal sacs can leave blood on the stool or around the bottom.¹ See anal gland problems in dogs.
• Inflammatory bowel disease and food sensitivities: chronic gut inflammation can cause recurring diarrhea with blood or mucus.^1,3 See IBD in dogs.
• Swallowed objects: bones, toys and other foreign bodies can injure the gut or cause a blockage.¹ See bowel obstruction in dogs.
• Medications: anti-inflammatory pain relievers (NSAIDs), including human drugs such as ibuprofen, naproxen and aspirin, can cause stomach and intestinal ulcers. Bloody or black stool is a warning sign.^7,1
• Poisons: anticoagulant rat and mouse poisons interfere with blood clotting and can cause bleeding into the gut and elsewhere.⁸
• Pancreatitis, liver disease, kidney failure and Addison's disease: pancreatitis can cause bloody stool, and liver disease, kidney failure and Addison's disease can cause black, tarry stool (melena).¹ See pancreatitis in dogs and Addison's disease.
• Tumors: polyps and cancers of the stomach, intestine or rectum can bleed, especially in older dogs.¹ See intestinal cancer in dogs.
• Clotting disorders: any problem that stops blood from clotting normally can show up as blood in the stool.¹

Jelly-Like Bloody Diarrhea: Acute Hemorrhagic Diarrhea Syndrome (HGE)

Acute hemorrhagic diarrhea syndrome (AHDS), still often called hemorrhagic gastroenteritis or HGE, causes sudden, profuse bloody diarrhea that is "often said to resemble raspberry jam." Vomiting, poor appetite, lethargy and belly pain are common, and vomiting may come before the diarrhea.⁴

• Who gets it: it is most common in small and toy breeds, such as Yorkshire Terriers, Miniature Pinschers, Miniature Schnauzers, Miniature Poodles and Maltese. The median age is about 5 years. It is not considered contagious.⁴
• Cause: not fully understood, but it may be linked to the bacterium Clostridium perfringens and its toxins.⁴
• Diagnosis: dogs lose so much fluid into the gut that their blood becomes concentrated. A packed cell volume (PCV) above 60% is a typical finding.⁴
• Treatment: prompt intravenous fluids are the mainstay of treatment. Antibiotics are not recommended for mild to moderate cases; a study of dogs without signs of sepsis found that antibiotics did not change survival, hospital stay or severity. They are reserved for dogs with signs of severe or spreading infection.⁴
• Outlook: good with treatment. Fewer than 10% of hospitalized dogs die, but mortality can be high if it is not treated.⁴

Read more on our page about hemorrhagic gastroenteritis in dogs.

Blood in Puppy Stool

Bloody stool in a puppy needs prompt attention, because puppies dehydrate quickly and two of the most dangerous causes are most common in young dogs:

• Parvovirus: puppies between 6 and 20 weeks old and dogs that are unvaccinated or not fully vaccinated are at highest risk. Signs include lethargy, loss of appetite, vomiting, fever and "severe, often bloody, diarrhea." The virus survives for long periods in the environment and spreads easily, so infected dogs must be isolated. Prompt, intensive hospital treatment improves survival.²
• Hookworms: puppies can be infected through their mother's milk and develop severe anemia, sometimes fatal, as early as 1–2 weeks of age, even before eggs show up in a stool test.⁶

The parvovirus vaccine is a core vaccine for all dogs. Puppies usually start the series at 6–8 weeks, with the final dose at 16 weeks or older.² See a reader's question about a puppy with bloody stool.

What Will the Vet Do?

Your vet will ask about your dog's diet, anything they may have eaten, medications, vaccinations and parasite prevention, then examine them. Depending on the findings, tests may include:¹

• Fecal tests for parasites and infections. Because whipworm eggs are shed intermittently, one negative test does not always rule them out.⁵
• Blood tests to check for blood loss, dehydration and organ problems. See our guide to dog blood tests.
• A parvovirus test for puppies and unvaccinated dogs
• X-rays or ultrasound to look for foreign objects, blockages or tumors
• Endoscopy or colonoscopy with biopsies for ongoing or unexplained bleeding

Treatment for Blood in Dog Stool

Treatment depends on the cause and how sick your dog is:¹

• Fluids, given under the skin or into a vein, to treat or prevent dehydration^1,4
• Deworming for parasites, followed by ongoing prevention, such as a monthly broad-spectrum preventive your vet recommends^5,6
• Diet changes, such as a short-term bland diet,¹ then an easily digestible, high-fiber, or novel or hydrolyzed protein diet for colitis³
• Probiotics, which may improve outcomes in dogs with short-term diarrhea that has no identifiable cause, although the evidence is weak and results vary by product⁹
• Antibiotics only when a bacterial infection or sepsis is suspected; most uncomplicated cases don't need them⁴
• Vitamin K1 for rat-poison exposure, often for 2–4 weeks, with blood transfusions for severe bleeding⁸
• Hospital care, surgery or cancer treatment for severe illness, obstructions or tumors¹

What You Can Do at Home (and What to Avoid)

For a dog that has had a single small streak of blood and is otherwise bright and well, your vet may suggest monitoring at home. If so:

• Make sure your dog has fresh water at all times, and watch for signs of dehydration.
• Feed only what your vet recommends, often a bland diet in small portions, and go back to the regular food gradually.¹
• Keep a note of each bowel movement and bring a fresh sample to the vet.

Don't give these without your vet's advice:

• Pepto-Bismol: it contains a salicylate (an aspirin relative), can turn stool black and hide bleeding, and should not be combined with dog NSAIDs such as Rimadyl.¹⁰
• Imodium (loperamide): it can cause serious neurological toxicity in dogs with the MDR1 gene mutation, common in Collies, Australian Shepherds, Shelties, other herding breeds and some other breeds.¹¹
• Human pain relievers: ibuprofen, naproxen and aspirin can cause stomach ulcers and bleeding in dogs.⁷
• Garlic: older home-remedy advice, including an earlier version of this page, recommended garlic. Garlic is toxic to dogs; it damages red blood cells and is 3–5 times more toxic than onion.¹²

Preventing Blood in Your Dog's Stool

• Keep your dog on the parasite prevention your vet recommends and have stool tested regularly. CAPC recommends testing puppies at least four times in their first year and adults at least twice a year.⁵
• Keep parvovirus and other core vaccinations up to date.²
• Change foods gradually, and keep garbage, bones, toys small enough to swallow and table scraps out of reach.¹
• Store rat and mouse poisons and all medications where your dog can't get to them, and never give human pain relievers without asking your vet.⁷

Related pages: dog diarrhea, bloody diarrhea in dogs, dog vomiting blood and Giardia in dogs.

Frequently Asked Questions

Is blood in dog stool an emergency?

It can be. Go to a vet right away if there is a lot of blood, black tarry stool, or watery bloody diarrhea, or if your dog is vomiting, weak, has pale gums, is a puppy or may have eaten poison. A small streak of fresh blood in a dog that is otherwise acting normally is less urgent, but you should still call your vet the same day.

Why is my dog pooping blood but acting normal?

A frequent reason is mild irritation or inflammation of the colon, often after eating something unusual, a sudden diet change or straining. Whipworms and other parasites can also cause blood without making a dog seem sick, so have a stool sample checked.

What can I give my dog if he is pooping blood?

Call your vet before giving anything. Fresh water and, if your vet agrees, a bland diet in small meals are usually the first steps. Don't give Pepto-Bismol, Imodium, human pain relievers or garlic without veterinary advice.

Will blood in a dog's stool go away on its own?

Some mild cases of colon irritation clear up on their own, but blood from parasites, parvovirus, poisons, ulcers or tumors needs treatment. Because you can't tell the cause at home, call your vet rather than waiting to see.

What does GI bleed poop look like in dogs?

Bleeding from the stomach or small intestine makes stool black, sticky and tar-like (melena). Bleeding from the colon or rectum shows up as bright red blood, often with mucus.

What does it mean when dog poop is jelly-like with blood?

Jelly-like mucus with fresh blood usually points to colitis. Large amounts of watery, jam-like bloody diarrhea, especially with vomiting, suggest acute hemorrhagic diarrhea syndrome, which needs urgent treatment.

What does parvo poop look like?

Parvovirus typically causes severe, watery and often bloody diarrhea, usually with vomiting, lethargy and loss of appetite. Any puppy or unvaccinated dog with these signs should see a vet immediately.

How long does bloody diarrhea last in dogs?

It depends on the cause, and there is no standard timeline. Dogs with acute hemorrhagic diarrhea syndrome have a good outlook with prompt IV fluids. Don't wait to see how long it lasts: call your vet the same day, and go in right away if there is a lot of blood, vomiting or lethargy.

Can a dog survive bloody diarrhea?

Many dogs recover with prompt veterinary treatment, depending on the cause. For example, fewer than 10% of dogs hospitalized for acute hemorrhagic diarrhea syndrome die. Delaying care for parvovirus, rat poison or severe AHDS can be fatal.

What will the vet do for bloody stool?

Your vet will examine your dog and usually test a stool sample, and may run blood tests, a parvovirus test, X-rays or ultrasound. Treatment can include fluids, deworming, diet changes and, for some causes, antibiotics.