Finding blood clots in your dog’s stool can be a frightening sight. Unlike small streaks of red, blood clots often mean there’s more than just mild irritation — they indicate bleeding somewhere in the digestive tract.
We outline the common causes of dogs pooping out blood clots, what you can do at home, and when to seek veterinary help.
Dog Pooping Out Blood Clots — Why It Happens
When a dog poops out blood clots, it usually means there’s significant irritation, inflammation, or damage to the intestinal or rectal lining. The clots form when blood pools inside the digestive tract and partially coagulates before being passed with stool.
Common causes include severe colitis, intestinal infection, ulcers, trauma to the rectum, or even internal bleeding from toxins or disease.
Because blood clots in stool are rarely minor, it’s important to identify the source quickly and get veterinary help if the bleeding persists or worsens.
Dog Pooping Out Blood Clots: Common Causes
1. Hemorrhagic Gastroenteritis (HGE)
Hemorrhagic gastroenteritis, or HGE, is one of the most common causes of sudden, bloody stools and visible clots in dogs.
This condition causes severe inflammation in the intestines, leading to profuse bleeding and watery, often foul-smelling diarrhea mixed with dark red clots. HGE often develops rapidly, and affected dogs may also vomit, refuse food, or become lethargic.
The exact cause of HGE isn’t always known, but it’s often linked to stress, bacterial imbalance, or dietary indiscretion. Without prompt fluid therapy, dogs can become dangerously dehydrated within hours.
Read more: Dog Pooping Mucus and Blood (Here’s it happens)
2. Severe Colitis
Colitis is inflammation of the colon, and when it becomes severe, it can lead to bleeding significant enough to produce clots.
This inflammation may result from food intolerance, parasites, bacterial infections, or stress. In these cases, you might notice frequent straining, soft stool with bright red blood, or mucous-coated feces.
Because the bleeding originates from the lower digestive tract, the blood tends to be bright red and may appear in larger globs or clots, especially if your dog strains to defecate repeatedly.
Chronic or recurring colitis requires dietary adjustments, probiotics, or medication to control inflammation.
3. Gastrointestinal Ulcers
Ulcers in the stomach or upper intestines can also cause dogs to poop blood clots.
These ulcers develop when the protective lining of the digestive tract is eroded by stomach acid, infection, or medications such as steroids or NSAIDs.
As ulcers bleed internally, the blood can pool and coagulate, forming dark red or black clots that pass in stool.
In some dogs, you may also notice vomiting (sometimes with coffee-ground material), loss of appetite, or pale gums. Ulcers are dangerous because they can lead to internal bleeding or perforation of the stomach lining if untreated.
4. Parvovirus or Other Infections
Parvovirus is a life-threatening infection that causes severe intestinal bleeding, often resulting in dark stools or visible blood clots.
This virus primarily affects unvaccinated puppies, but adult dogs can also contract it. The virus destroys intestinal cells, leading to hemorrhaging, vomiting, and profound dehydration.
Other bacterial or parasitic infections — like Salmonella, Giardia, or Clostridium perfringens — can also trigger intestinal bleeding and bloody stool with clots. Dogs with infectious causes may appear weak, feverish, or unwilling to eat, and their diarrhea often smells foul.
Immediate veterinary attention and supportive care are crucial in these cases, as infections like parvo can be fatal if not treated quickly.
5. Trauma to the Rectum or Anus
Sometimes, the cause of blood clots in stool isn’t from the intestines but from the lower end of the digestive tract.
Rectal or anal trauma can occur from swallowing sharp objects, passing hard stool, or even after a rectal thermometer or enema. These injuries can cause localized bleeding that forms clots before being expelled.
You might notice your dog licking their rear frequently, straining to poop, or whining during defecation. Anal gland abscesses or ruptures can also cause visible bleeding near the anus, which may mix with stool and look like clots.
While mild trauma can heal on its own, persistent bleeding or pain requires a vet visit to prevent infection.
6. Internal Bleeding or Toxins
One of the more serious causes of blood clots in a dog’s stool is internal bleeding.
This may occur due to rodenticide (rat poison) ingestion, which interferes with the blood’s ability to clot. As a result, internal bleeding can occur in the gastrointestinal tract and lead to dark, clotted stool or even tar-like diarrhea.
Other causes include tumors, bleeding disorders, or organ disease affecting the liver or spleen. Dogs may show additional signs such as weakness, pale gums, labored breathing, or collapse.
If you suspect toxin ingestion or internal bleeding, immediate emergency care is essential.
Read more: Dog Pooping Blood No Other Symptoms (What it means)
What to Do If Your Dog Is Pooping Out Blood Clots
Seeing blood clots in your dog’s stool can be alarming, but your response can make all the difference.
First, take note of the color and texture of the blood. Bright red clots often indicate bleeding near the rectum or colon, while darker or jelly-like clots suggest bleeding higher up in the digestive tract.
If your dog seems otherwise alert, hydrated, and eating, you can contact your vet and describe the symptoms. Avoid giving any over-the-counter medication — especially human drugs like Pepto-Bismol or pain relievers — as these can worsen internal bleeding.
Provide plenty of fresh water to prevent dehydration, and feed a bland diet of boiled chicken and rice or a prescription gastrointestinal formula until your vet advises otherwise. This helps soothe inflammation and reduce irritation in the gut.
If your vet suspects mild colitis or antibiotic-induced irritation, they may recommend probiotics or a fiber supplement to help restore normal bowel health.
Keep your dog calm and comfortable, and monitor every bowel movement. If the clots increase in size, or your dog becomes weak, stop eating, or vomits blood, seek emergency veterinary care immediately.
When to Call or Visit Your Vet
Any time your dog poops out blood clots, you should treat it as a potentially serious sign.
Call your vet immediately if:
The stool contains large, dark, or tarry clots.
Your dog is lethargic, vomiting, or not eating.
You suspect toxin ingestion (rat poison, spoiled food, human medication).
The bleeding persists for more than 24 hours.
If your dog’s gums are pale or their breathing seems shallow, these can indicate internal bleeding or anemia — both medical emergencies that require urgent treatment.
Puppies, senior dogs, or those with pre-existing health issues should be seen right away, even if symptoms seem mild, since they can deteriorate rapidly from fluid loss and infection.
Bring a stool sample to your vet if possible; it can help identify parasites, infections, or the presence of digested blood.
Read more: Dog Pooping Blood from Stress (When anxiety affects digestion)
Key Takeaway
If your dog is pooping out blood clots, it’s a sign that something more serious than mild irritation is happening.
From hemorrhagic gastroenteritis to ulcers or internal bleeding, clotted blood in stool always deserves prompt veterinary evaluation. Supporting your dog with hydration, a gentle diet, and a calm environment can help during recovery, but professional diagnosis is the safest way forward.
Even if your dog seems fine otherwise, don’t ignore this symptom — quick veterinary attention can prevent complications and ensure your dog gets the care they need.