There are many potential causes for bloody diarrhea in dogs, and your vet is the only one that can diagnose the reason and suggest a treatment plan. You can help speed up the process by recognizing the type of bloody stool your dog is having.

There are two types of bloody stools in dogs, and they can be easily distinguished:

Hematochezia has the appearance of bright red and fresh blood in the dog's feces. This blood comes from the lower part of the digestive tract, and there are numerous potential causes.

Melena has a black and tarry blood look with sticky feces, and it occurs when the dog swallows or digests blood. It is usually the result of bleeding in the upper digestive tract and also has many possible causes.

As soon as you see blood in your dog's stool, you should contact a veterinarian if you can describe to them which type of bloody stool your dog has. It would help with quicker and more accurate diagnosis and treatment.

Types of bloody stoolsHematocheziaMelenaBright-red color blood in the stools black, tarry, and sticky stoolsBlood is fresh blood digested from the low parts of the digestive comes from the upper gastrointestinal tract.


Causes of Bloody Diarrhea in Dogs


In the case of hematochezia in your dog, the blood in their stool comes from the rectum or colon. There are numerous possible causes, but the most common are below.


Frequent changes, such as traveling or moving, going to a kennel, or the presence of a new pet in the house, can be stressful for a dog. The result may cause colitis with the mucous and bloody stools.

Overeating and inadequate diet

Overfeeding, spoiled food, a sudden change in the dog's diet, and food intolerance may irritate a colon and cause mucous diarrhea and bloody stools.

Parasites and protozoans

Hookworms, roundworms, and whipworms are the most common causes of bloody diarrhea in dogs. Coccidia is also a frequent cause of the same disorder.


Parvovirus is rare in puppies, especially Dobermans, Rottweilers, and German Shepherds, and often causes bloody stool. Since it is a highly fatal disease, visiting the vet immediately is obligatory.

Rectal injury

Sometimes, the dog may ingest a sharp object such as bone or stick, which can scrape their intestines or rectum lining. As a result, some blood will occur in the stools.

Rectal polyp

If the polyp is present in the dog's rectum, well-formed stools may pass over it and cause the occurrence of fresh blood on the feces' surface.

Hemorrhagic gastroenteritis

Another prevalent reason for bloody diarrhea, but scientists have yet to discover the real cause of hemorrhagic gastroenteritis in dogs, and the condition remains idiopathic.

Infusion and appropriate therapy can save a dog's life once copious blood occurs in the feces.


In the case of melena in dogs, digested blood in stool comes from their pharynx, esophagus, lungs, stomach, or small intestine. The most common causes are below.

Use of NSAIDs

Regular consumption of aspirin or another medication from the NSAID group may cause ulcers in the dog. The ulcer then starts bleeding, and black, tarry feces will appear as a result.


Giving Pepto-Bismol to dogs to settle their stomach is not that rare, but this drug may temporarily result in the black stool's occurrence.

The feces will turn back to normal shortly after consumption stops.

Ingestion of blood

In some situations, a dog's bloody feces occur when the dog ingests the blood after nose bleeding or mouth injury or licks a bleeding wound.

Complication after the surgery

If the black stool occurs 24 to 72 hours after the surgery, internal bleeding should be suspected. You must urgently take the dog to the vet.

Blood clotting disorder

This condition often occurs after taking rat poison. This is a potentially fatal condition, and it is necessary to ask for emergency veterinary assistance.


Cancer is fairly common in elderly dogs and can sometimes cause bloody diarrhea. It is required to take the animal to the vet as soon as you notice dark stool.

What to Do When You Notice Bloody Stool?

Once the bloody stools occur, you should immediately take the dog to the vet and not attempt to treat the condition yourself.

Collecting feces for testing before visiting the ambulance is a practical option, which can speed up the diagnosis process.

Before starting with therapy, it is recommended to avoid feeding the animal at least 12 to 24 hours after the blood is noticed for the first time.

That is the way to let the intestines recover as much as possible.

Depending on the primary cause of bloody diarrhea in the dog, water can be prohibited, or it will be necessary for providing an unlimited amount of liquid for the animal to avoid dehydration or even septic shock.

Once the vet diagnoses the cause of blood in the stool, they will determine adequate treatment.

Depending on the reason for this condition, the veterinarian may recommend just a different diet for several days. On the other hand, medications or surgery can be the only option in more severe cases.


No matter what the cause of bloody diarrhea in dogs is, an urgent vet visit is mandatory. Your vet won't have any difficulties in differentiating between hematochezia and melena after taking a stool sample.

However, it is sometimes necessary to do additional tests to confirm the diagnosis, such as:

  • Blood testing
  • Urinalysis
  • Examination by X-rays or Ultrasound
  • Tissue biopsy
  • A fecal occult blood test


As always, preventing bloody diarrhea is better than treating it.

Because there's a large number of possible causes, the best way to prevent the development of bloody stools is keeping the dog healthy and away from diseases:

  • Providing a healthy, balanced diet
  • If switching to a new food, do so gradually
  • Regular exercise for the dog
  • Keeping the dog away from toxins and dangerous foreign objects
  • Monitoring the level of stress
  • Prevention of intestinal parasites; use of dewormers
  • Taking care of timely vaccination
  • Visiting the vet regularly

At the Tail's End…

Bloody diarrhea in dogs is a clear warning sign that something wrong is happening in your pet's body.

Once it appears, there is no time to wait. It is necessary to take the animal to a veterinary clinic right away since some conditions causing bloody stools are life-threatening.

Fortunately, there is no reason for concern in most cases, and time will solve the problem without consequences.

Common Questions about Your Dog's Bloody Diarrhea

Whether you still have questions about your dog's poop or want more information on what to do when you notice bloody diarrhea or bright red blood in your dog's poop, the following FAQs can help.

They cover information on your dog's stool, dog's poop, lower and upper digestive tract, and stomach ulcers.

Most importantly, take your dog to the veterinarian if bleeding occurs suddenly or excessively. You may want to take a sample of your dog stool as well.

Is Bloody Diarrhea in Dogs an Emergency?

Bloody diarrhea can be an emergency. You should always contact your vet right away if you notice blood in a dog stool, as it can indicate serious problems.

There are some potentially minor causes of this blood, but there may also be a serious problem.

Your dog's vet will have to examine and test his upper digestive tract and overall digestive tract. When you call the vet to make the appointment, ask if they want a sample of your dog's stool to check for viral and bacterial infections.

Most vets will want to examine the dog's stool thoroughly.

Expect a thorough examination as the bloody stool can indicate issues with your dog's stomach, colon, intestine, lower digestive tract, upper digestive tract, or liver disease.

There are dozens of potential causes of bloody diarrhea, including viral and bacterial infections, stomach ulcers, intestinal ulcers, sudden dietary changes, liver disease, or foreign bodies.

Other underlying cause possibilities include heavy metals, a reaction to medications, ulcers, dehydration, parasites, or a more serious problem like cancer.

The urgency of the situation depends on the disease in question and other causes behind it. As such, your vet will ask about any sign you have noticed.

Even if your dog does not have difficulty breathing, it is best to immediately take him to the veterinarian.

You are not trained to evaluate your dog's condition and cannot complete blood work to discover what caused diarrhea, and you find blood in it.

What Can I Give My Dog for Bloody Diarrhea?

When you notice your pup has bloody diarrhea but don't see any other symptoms, it may not be an emergency.

You can try giving not giving your dog food for between 12 and 24 hours. After that, only give him a bland diet.

If this doesn't ease your dog's condition, you will need to take him to a doctor of veterinary medicine.

The most important thing is to ensure that your dog gets enough water. That should be consistent throughout any dietary changes.

Always take your dog to the vet if the symptoms persist. Bleeding may indicate a more serious problem. It is essential to discover the cause of the bloody poop to care for your dog's overall health.

Why Does My Dog Have Diarrhea But Is Acting Normal?

Sometimes, your dog may have bloody diarrhea or just diarrhea but still act normal. In this case, the stomach problems are likely due to a less serious issue.

Diarrhea with red blood may be from one of several underlying cause options. Your dog may have eaten something he should not, or maybe you changed his food too abruptly.

Red blood in diarrhea may also be from an underlying cause like antibiotics or other medicines.

Some medications disrupt your dog's gastric flora. Blood in your dog's stool can also be due to stomach ulcers or infectious agents. Parvovirus is particularly common in dogs.

How Long Does Hemorrhagic Gastroenteritis Last in Dogs?

Hemorrhagic gastroenteritis (HGE) will typically last between two and four days in dogs.

As long as you take your dog to the vet for treatment, he should recover well. Left untreated, however, it can be hazardous for the digestive tract.

One of the first signs of HGE is if you notice red blood in your dog's stool.

Can a Dog Survive Hemorrhagic Gastroenteritis?

If your dog is diagnosed with HGE, he should be fine in most cases. That is assuming that you see the vet immediately to start treatment for diarrhea and other symptoms.

The early treatment should be aggressive and appropriate to give your dog a good chance at survival. Veterinarians estimate that less than 10% of dogs that receive HGE treatment die.

That being said, expect your dog to have a hard time during parts of the illness and treatment.

Most dogs with HGE have to be hospitalized for at least one full day. This close supervision lets your vets check blood work, run other tests, and ensure a veterinarian team observes your pet.

They will likely monitor the dog stool and check the digestive tract and other areas for viral and bacterial infections.

Most importantly, a veterinarian will be on hand in case severe bleeding occurs. It also helps prevent dehydration from vomiting and diarrhea.

Can You Treat Hemorrhagic Gastroenteritis in Dogs at Home?

If your dog has bright red blood in his stool from hemorrhagic gastroenteritis, follow your veterinarian's advice about treatment.

He may want to observe and monitor your dog in the vet hospital for at least 24 hours.

He may also suggest some at-home treatment once your pet is past the most dangerous stages. Your veterinarian will suggest giving your dog a bland diet.

Your vet may also recommend canned pumpkin, rice, or lean protein. These are also easy on your dog's stomach. Canned pumpkin also provides easily digestible fiber.

When Should I Take My Dog to the Vet for Bloody Diarrhea?

You should take your dog to the vet for bloody diarrhea if you also notice other signs and symptoms.

Other worrisome signs include refusing to eat, looking unwell, or vomiting. You also want to bring him to the vet if the blood in his poop continues.

Look for warning signs of something more serious, such as difficulty breathing.

If you notice the symptoms during normal operating hours, call your vet for an emergency appointment. Describe the sign or symptoms you noticed over the phone.

If your vet's office is not open, call the emergency number. Bloody diarrhea could potentially be a matter of life and death.

Getting an emergency appointment can be crucial to your dog's health.

What Will a Vet Do for Bloody Diarrhea?

How your veterinarian decides to treat your dog's bloody diarrhea will depend on his symptoms and the likely causes. He may prescribe medications, such as probiotics, dewormers, or antidiarrheal agents.

If the problem is from an infection, then your veterinarian will directly treat that infection with medications in addition to prescribing those medicines.

If you have more than one pet, the veterinarian may also ask to see the other pets.

Your vet will likely try to determine the possible causes of the bleeding before suggesting a treatment. The treatment varies for different medical conditions.

For example, if the underlying cause is liver disease, the treatment will be different from ulcers.

Expect a different treatment for parasites, cancer, colon issues, infections, vomiting, bright red and duller blood, and other causes.

However, one common theme is that your veterinarian will likely recommend sudden dietary changes to give your pup bland foods temporarily.

This should reduce the chances you notice blood again.

Can Dog Food Cause Bloody Diarrhea?

Yes, if your dog eats the wrong thing, this can cause issues with his digestive tract. That, in turn, can lead to bloody diarrhea.

For example, sudden dietary changes can irritate your dog's stomach.

Your pup's intestines may also become irritated if your dog eats something he shouldn't or doesn't typically eat. This is called dietary indiscretion.

Eating foreign bodies, such as plastic or clothes, is a common possibility. This can lead to intestinal inflammation as well. Both irritation and inflammation can cause bloody diarrhea.

What Does Parvo Poop Look Like?

In addition to your dog's poop having blood, you want to be aware of other symptoms. Looking at the other symptoms can help you determine the cause.

One explanation, for example, is parvovirus (parvo). Dogs with parvo will have diarrhea as well as vomiting.

The vomit is usually brown, yellow, or clear. You will typically find blood in the diarrhea of dogs with parvo. Other than the blood, the poop may be mustard-colored or light yellow.

What Are the Signs of Parvo in a Dog?

If you are concerned about your dog having parvo, learn the potential signs. Bloody diarrhea is one of them, but you will typically see other signs than blood in the stool.

It is worth noting that this bloody diarrhea tends to be severe. A dog with parvo may also have symptoms like hypothermia (low body temperature) or fever and vomiting.

They may also lose their appetite and be lethargic. Dogs with parvo also frequently have bloating and abdominal pain.

READ NEXT: 15 Reasons for Blood in Dog's Stool

Dog Has Bloody Diarrhea

Shelly lives in Iowa with her husband and Australian Shepherd named Tex. She's been an animal lover since she was a child. Currently, she enjoys reading and writing about dogs, and spending time with her family and getting involved in all things pets.