It can be very alarming to see mucus in your dog’s stool, especially when streaks or spots of blood appear alongside it.
These changes in your dog’s bowel movements can point to illness in the digestive system that should not be ignored.
We outline the common causes of mucus in a dog’s poop with blood, what you can do at home, and when to seek veterinary help.
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Mucus in Dog Poop with Blood — Why It Happens
Finding both mucus and blood in a dog’s poop usually signals inflammation or irritation in the gastrointestinal tract. This may be triggered by infections, parasites, dietary changes, or more serious conditions like colitis or pancreatitis.
In some cases, bleeding can result from straining during constipation, while in others it may be caused by internal disease.
Because the causes range from mild to life-threatening, paying attention to the timing, frequency, and severity of these symptoms is crucial.
Mucus in Dog Poop with Blood: Common Causes
Colitis
Colitis, or inflammation of the colon, is one of the most common causes of mucus mixed with blood in a dog’s stool.
The colon produces mucus to protect its lining, and when it is irritated, this production increases.
Dogs with colitis may also strain while defecating, pass frequent small stools, or appear uncomfortable during bowel movements.
The blood present is usually fresh and red, suggesting it originates from the lower digestive tract. Stress, infections, food allergies, or sudden dietary changes can all trigger colitis.
Read more: Mucus in Dog Poop After Constipation (Why it happens and what to do)
Intestinal Parasites
Parasites such as whipworms, hookworms, and giardia can cause irritation and bleeding in the intestines.
These organisms damage the intestinal lining, leading to mucus as the body tries to protect itself, and blood due to the tissue damage.
Dogs with parasites may also experience diarrhea, weight loss, poor coat quality, or a distended abdomen.
Because parasite infestations can worsen quickly, especially in puppies, veterinary diagnosis and treatment are essential.
Dietary Indiscretion or Food Intolerance
Eating spoiled food, table scraps, or foreign objects can irritate the gastrointestinal tract.
In some cases, dogs may have underlying food intolerances or sensitivities that trigger excess mucus production and bleeding when certain ingredients are consumed.
Signs often include vomiting, loose stools, and abdominal discomfort in addition to the blood and mucus in the stool. Switching foods too quickly can also cause these symptoms.
Bacterial or Viral Infections
Infections such as parvovirus, salmonella, or campylobacter can cause severe gastrointestinal inflammation.
These conditions often produce bloody, mucus-filled diarrhea that can become life-threatening if dehydration or sepsis develops.
Dogs affected by infections may also appear weak, lose their appetite, vomit frequently, or develop a fever. Parvovirus is especially concerning in unvaccinated puppies, where it requires emergency treatment.
Pancreatitis
Pancreatitis occurs when the pancreas becomes inflamed, releasing digestive enzymes that irritate surrounding organs, including the intestines.
This inflammation can result in mucus-coated stool with blood present, as the intestines become stressed and irritated.
Dogs with pancreatitis may also vomit, refuse food, hunch over in pain, or appear lethargic. High-fat diets and certain medications can increase the risk of pancreatitis episodes.
Constipation and Straining
Constipation can also result in mucus and blood in a dog’s stool. When a dog strains excessively, small blood vessels in the lower rectum may rupture, leading to streaks of red blood.
The colon may also produce more mucus to try to ease the passage of hard or dry stools.
Dogs struggling with constipation may have infrequent bowel movements, pass very firm stools, or show signs of discomfort while trying to defecate.
What to Do If Your Dog Has Mucus in Their Poop with Blood
If your dog’s stool contains both mucus and blood, monitor the situation closely. A one-time occurrence after a sudden dietary change may resolve on its own with a bland diet and rest.
Feeding easily digestible meals, such as boiled chicken and rice, can give the digestive system a chance to recover.
Ensure your dog has access to plenty of fresh water, as both diarrhea and blood loss can contribute to dehydration. Keep your dog from eating trash, spoiled food, or new treats while monitoring their condition.
If your dog is stable and otherwise acting normal, you can observe at home for 24–48 hours. However, persistent symptoms, worsening stool quality, or additional signs of illness warrant a veterinary visit.
When to Call or Visit Your Vet
Seek immediate veterinary care if your dog is lethargic, refusing to eat or drink, vomiting repeatedly, or has large amounts of blood in the stool. These may indicate a serious infection, pancreatitis, or another critical condition.
Puppies, senior dogs, and dogs with underlying health issues are more vulnerable to rapid deterioration and should be seen by a vet sooner rather than later. Black, tarry stools are especially concerning, as they may suggest internal bleeding higher up in the digestive tract.
If your dog’s symptoms persist beyond 48 hours, worsen in severity, or are accompanied by abdominal pain or fever, professional evaluation is essential to determine the cause and start treatment.
Read more: Orange Mucus in Dog Poop (What the color means for your dog’s health)
Key Takeaway
Seeing mucus in dog poop with blood is a concerning sign that usually indicates irritation or inflammation of the digestive tract.
While mild cases may resolve with dietary rest, many underlying causes—such as parasites, infections, or pancreatitis—require veterinary care.
Pay close attention to your dog’s overall behavior, appetite, and stool changes. When in doubt, it is always safest to contact your veterinarian for guidance and to rule out serious illness.