Why Does My Great Dane Always Have Diarrhea? (Here’s Why)

Production of loose stools in large quantities is commonly referred to as diarrhea. Dog diarrhea is a symptom of different diseases or conditions.

The severity of diarrhea can be severe or mild depending on the underlying cause.

Occasional episodes of diarrhea in Great Danes is common and normal however frequent diarrhea can be a sign of a serious underlying problem.

 If it’s frequent, what causes a Great Dane to always have diarrhea?

Let’s look at the common reasons why frequent Great Dane diarrhea occurs.

Why Does My Great Dane Always Have Diarrhea?

A Great Dane may always have diarrhea because of intestinal infection, dietary indiscretion, change in diet, stress, allergic reaction, side effects of medication, and organ dysfunction. Diarrhea is a symptom of an internal problem therefore medical attention is required when it occurs frequently.

great dane always have diarrhea

Reasons Why Your Great Dane Always Has Diarrhea

The most common causes of persistent or chronic diarrhea in a Great Dane include:

Gastrointestinal infection

Gastrointestinal infection by bacteria, intestinal parasites, or viruses is the most common cause of diarrhea in a Great Dane.

A Great Dane can become infected by drinking or eating contaminated food or water.

Bacterial infections include Salmonella, coccidia, or Escherichia coli (E. coli) while viral infections include parvovirus. 

Parasitic infections can be from roundworms, hookworms, tapeworms, and whipworms.

Related: Great Dane bloody diarrhea: what it means

Dietary indiscretion

All dogs explore their world with their nose and mouth. They will tend to eat anything that smells interesting and due to curiosity, they may chew and swallow nonedible items. 

This includes toxins, garbage, plants, objects, spoiled food, or human food, which upset their stomach and cause diarrhea.

Change in diet

A change in diet can lead to a Great Dane having persistent diarrhea. If you have changed your dog’s food, this is likely the cause of it.

This is because it takes time for your dog’s stomach to adjust to the new food and a sudden change to a new may cause diarrhea. 

A Great Dane may also experience food intolerance meaning that they may not be able to properly digest some of the food ingredients in the new diet which also leads to diarrhea. 


A stressed Great Dane also experiences diarrhea. Stress and anxiety cause a variety of symptoms including pacing, licking, drooling, yawning, crying, barking, avoidance, and also diarrhea.

Stress can come from a variety of sources such as a change in their environment or routine, new people or pets, loud noises, and other fear-related stressful situations.

Allergic reaction

Allergic reactions cause various symptoms in a Great Dane including diarrhea. Allergic reactions stem from different sources including environmental triggers, skin allergies, and food allergies.

Therefore if a Great Dane is experiencing persistent diarrhea, allergies are also likely to be the underlying cause.

Side effects of medication

Many medications cause diarrhea. Therefore if a Great Dane is under medication, they may have persistent diarrhea.

The medication may also cause diarrhea and loss of appetite in a Great Dane due to nausea.


Many diseases and conditions cause diarrhea as a symptom including organ dysfunction, that is, kidney or liver disease, inflammatory bowel syndrome, colitis, or cancer.

Read more: Great Dane sensitive stomach: Causes and how to help


The most serious complication of diarrhea is severe dehydration which leads to multiple organ failure, unconsciousness, and death.

If not treated in time, it can be life-threatening to a Great Dane. 

Diarrhea is also a symptom of many serious conditions which can be life-threatening if left untreated. This includes infections, cancer, or organ diseases.

When To Seek Help

The severity of diarrhea is determined by the length of time it has lasted and the presence of other symptoms of illness. 

Diarrhea should be treated as an emergency especially when it occurs more than once.

Seek medical help when:

  • Other symptoms of illness are present such as vomiting, lethargy, fever, or loss of appetite
  • There is blood in the stool 
  • The diarrhea is continuous 
  • If your Great Dane is under medication
  • If your Great Dane has an existing health condition 

Immediately contact the veterinarian within 8 to 12 hours if your Great Dane has continuous diarrhea, that is when they diarrhea more than once.

Carry a stool sample which will be tested. The veterinarian will ask for information regarding your Great Dane’s symptoms, behavior, and also their history to help reach a diagnosis.

In addition to this, other diagnostic tests will also be conducted to determine the cause of persistent diarrhea.

Related: Why is my Great Dane pooping blood?


Treatment for Great Dane diarrhea will depend on the underlying cause.

Depending on the severity of diarrhea, the veterinarian will either recommend home care or hospitalization.

Initial treatment consists of the provision of anti-diarrhea medication and also probiotics. 

Withdrawal of your dog’s current diet for 12 – 24 hours is advised. This is done to allow the gastrointestinal tract to heal itself, alongside the provision of plenty of drinking water.

After the waiting period, your dog will be on a bland diet consisting of boiled rice or pasta with boiled chicken. This diet also allows the gut to heal before reintroduction of your dog’s regular diet. 

Dietary change is also a possible recommendation if your Great Dane has food allergies or intolerance. Your dog’s diet will be changed to a limited ingredients diet or a prescribed diet.

Antibiotics for bacterial infection may be prescribed if your dog has a bacterial infection parasitic infection or dewormers for parasitic infection. 

Toxin ingestion will also be determined and treated. 

If the diarrhea is a result of stress, stress management strategies are recommended to help calm your dog in stressful situations.

This includes providing a predictable schedule for exercise, play, and feeding, to prevent stress due to changes to their normal routine. Also, limit your dog’s exposure to stress triggers such as new people or environments.

Further reading: How to stop separation anxiety in Great Danes

In severe cases of dehydration, hospitalization may be required. Intravenous fluids will be administered for rehydration and replacement loss of electrolytes.


Persistent diarrhea in a Great Dane is a sign of an underlying problem. It is not normal for a Great Dane to always have diarrhea.

It is a problem that requires immediate medical attention because it can lead to severe dehydration and deterioration of a dog’s health. 

Consult your veterinarian for determination of the underlying cause so that your dog can receive the appropriate treatment.

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