Great Dane Bloody Diarrhea: What Does It Mean?

It is quite alarming to see your great Dane having bloody diarrhea. Occasional short bouts of diarrhea is common in Great Danes however, when there is blood in a Great Dane’s stool, this is unusual.  

So, what causes Great Dane bloody diarrhea?

Let’s look at the reasons behind Great Dane bloody diarrhea, what you should do, and when to seek help.

Here’s Why Great Dane Bloody Diarrhea Happens

Great Dane bloody diarrhea is caused by underlying conditions affecting the digestive tract of a Great Dane, which includes intestinal parasites, bacterial or viral infection, stress, gastrointestinal trauma, toxin ingestion, disease, and esophageal or stomach tumors.

great dane bloody diarrhea

What Is Bloody Diarrhea?

Bloody diarrhea is loose runny stool with the presence of blood.  Bloody diarrhea  is not normal and is a sign of an underlying condition that affects a Great Dane’s digestive tract.

The blood in the loose stool may appear as as bright red blood or black and tarry blood. This appearance provides an insight to what part of the gastrointestinal part has a problem.

The appearance of bright red blood comes from the lower end of the intestines, that is the colon, rectum and anus. 

Black and tarry blood that looks like coffee grounds is partly digested blood that is from the stomach and small intestines.

Symptoms Of Great Dane Bloody Diarrhea

Great Dane bloody diarrhea is a symptom of underlying conditions therefore it will also occur with other symptoms including:

  • Dehydration
  • Lethargy
  • Weight loss
  • Lack of appetite
  • Blood in vomit
  • Blood in Great Dane stool

Reasons for Great Dane Diarrhea with Blood

The most common causes of bloody diarrhea in a Great Dane are:

Intestinal parasitic infection

Intestinal parasites can can cause bloody diarrhea in a Great Dane. The parasites irritate the lining of the gut, causing bleeding and also diarrhea.

This includes intestinal parasites such as hookworms, roundworms, tapeworms, and whipworms.

Bacterial or viral infections

Gastronintestinal infection by bacterisl or viral infections can cause bloody diarrhea. Bacterial infections by Salmonella, Escherichia coli (E. coli) and other bacterial agents cause this to occur. 

Viral infection by parvovirus commonly affects unvaccinated puppies but it can also infect older dogs. Parvovirus infection causes bloody diarrhea and severe vomiting.

Gastrointestinal injury

Great Danes will explore their environment by smelling, tasting, tasting and swallowing items. This includes non edible foreign objects such as rocks, toys, sticks, or sharp bones.

These items can cause injury along the digestive tract as they move within it causing gastrointestinal bleeding and also upset their stomach and causing  diarrhea. 

The internal trauma and the upset stomach leads to bloody diarrhea.

Related: Why does my Great Dane always have diarrhea?


Stress can cause a  Great Dane to have diarrhea in addition to other symptoms including constant pacing, yawning, licking, barking, drooling, crying, and avoidance.

Stress colitis  is a condition causes large bowel diarrhea due to the inflammation of the colon and reduced absorption and holding of feces. 

This causes small amounts of diarrhea which is often accompanied by mucus or blood.

Conditions that cause inflammation of the bowel cause diarrhea and vomiting and can also cause bloody diarrhea. 

Toxin ingestion

A Great Dane may also ingest a toxin which may irritate their gastrointestinal lining and lead to bleeding. Toxin ingesion as well leads to diarrhea and this results in bloody diarrhea.


Several diseases that a Great Dane might have can cause bloody diarrhea as a symptom.

This includes kidney or liver disease, bleeding disorders, hormonal disorders, hemorrhagic gastroenteritis, immune system diseases, ulcers and cancer.

See Also: Great Dane throwing up and diarrhea: Reasons why and what you should do

Esophagus and stomach tumors

Esophagus and stomach tumors affect the digestive tract causing bleeding and diarrhea. This results in bloody diarrhea.

Great Dane Bloody Diarrhea: What To Do

Bloody diarrhea indicated a serious underlying problem, therefore seek medical attention for your dog when you notice this.

Diarrhea can quickly lead to severe dehydration which results in organ failure, unconsciousness, and death.

Great Dane bloody diarrhea is also symptom of several serious health conditions are  life-threatening if left untreated.

Note other symptoms of illness that may be present alongside the diarrhea such as vomiting,  fever, lethargy, or loss of appetite to inform the veterinarian.

The veterinarian will conduct a full physical examination of your dog and conduct diagnostic tests to determine the cause of bloody diarrhea.

Tests that are conducted  include blood work, stool sample testing, urinalysis, x-rays and ultrasound.

Related: Why is my Great Dane pooping blood?

Treatment for Great Dane Bloody Diarrhea

Treatment for Great Dane bloody diarrhea depends on the diagnosis of the underlying cause. Treatment consists of:

  • Diarrhea treatment
  • Administration of fluids to correct dehydration 
  • Dietary changes
  • Administration of medication (antibiotics and anti inflammatory medication)
  • Deworming to treat intestinal parasites
  • Treatment of disease  

Hospitalization may be required in severe cases of dehydration for administration of intravenous fluids and also if surgery is required for removal of tumors.

Summary: Great Dane Bloody Diarrhea

Great Dane bloody diarrhea is concerning and is a sign that something  is wrong. It is important to seek immediate medical attention for it.

Bloody diarrhea is a sign of an underlying health problem and can quickly lead to dehydration and other serious complications if not treated.


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