Diarrhea in Dogs

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026
Table of contents

When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

?

ORANGE for dehydration, repeated Vomiting, Fever, severe abdominal pain, puppies/geriatric dogs, marked lethargy, or if it lasts >24–48 hours; RED for collapse/shock signs.

Unsure about what’s wrong with your pet? Feel free to use our Symptom Checker for more clarity

Definition

Diarrhea in dogs, also known as diarrhea, is a common digestive disorder characterized by loose or watery stools. It is a reaction of the digestive tract to various triggers or diseases and can occur as either acute or chronic.

Can Occur with the Following Diseases:

Basics and possible causes

Diarrhea is the result of disrupted water absorption or secretion in the intestine. Normally, water is absorbed in the colon, but with diarrhea this process is impaired. This can be caused by Inflammatory conditions, infections, toxins, or a poor diet.

Infections caused by bacteria, viruses, or parasites are common triggers of Diarrhea. Bacterial infections can be caused by Salmonella, E. coli, or Campylobacter. Viruses such as parvovirus or coronavirus can also lead to Diarrhea. Parasitic infections caused by Giardia or worms are also common.

Diet-related causes include sudden food changes, eating spoiled or unsuitable food, and food intolerances or allergies. These factors can disrupt the intestinal flora / gut microbiota and lead to Diarrhea.

Other possible causes include inflammatory bowel disease, stress, medications (such as antibiotics or NSAIDs), and systemic diseases such as liver or kidney problems. An unhealthy lifestyle or environmental stressors can also play a role.

Typical accompanying symptoms

  • Vomiting: Many dogs that suffer from Diarrhea also show Vomiting. This can be triggered by the same causes as Diarrhea and leads to further fluid loss (dehydration).
  • Loss of appetite: A dog with diarrhea may refuse to eat or only eat reluctantly, which indicates a general malaise or abdominal pain.
  • Lethargy: Dogs with diarrhea often show reduced activity and appear lethargic or tired because their body is fighting the causes of the diarrhea.
  • Fever: With infectious causes, the dog may develop Fever, which can be recognized by an elevated body temperature and a warm feeling when touched.
  • Dehydration: Due to fluid loss (dehydration), the dog may be dehydrated, which shows as dry mucous membranes, reduced skin elasticity, and sunken eyes.
  • Blood in the stool: In some cases, the diarrhea may be bloody, which indicates a more serious illness or injury to the intestinal wall.

When to see a vet?

A veterinarian should be consulted if the Diarrhea lasts longer than 24 to 48 hours or if it is accompanied by severe symptoms such as bloody stool, severe Vomiting, or Fever. These signs may indicate a serious condition that requires immediate treatment.

It is also advisable to seek veterinary advice early for young puppies, older dogs, or dogs with a weakened immune system, as they are more prone to dehydration and complications.

If the dog shows signs of dehydration or seems severely lethargic, an immediate visit to the veterinarian is also necessary to prevent further health damage.

Symptom recognition for the pet owner and veterinary diagnostic procedure

The pet owner should monitor the Diarrhea closely and note how often the dog defecates, what the stool consistency is like, and whether additional symptoms such as Vomiting or Fever occur. This information is important for the veterinarian to determine the cause of the Diarrhea.

The veterinarian will take a thorough medical history and may perform a physical examination. Depending on the dog’s symptoms and medical history, diagnostic tests may also be necessary. These include fecal tests to identify parasites, blood tests to check overall health, and possibly imaging such as X-ray or ultrasound to detect structural abnormalities in the digestive tract.

In some cases, an endoscopy or an intestinal biopsy is necessary to diagnose inflammatory or structural diseases. These tests help the veterinarian make an accurate diagnosis and plan an appropriate treatment.

What the pet owner can do and professional therapy options

The pet owner can initially try fasting the dog for 12 to 24 hours to give the digestive system a rest. It is important that fresh water is available at all times to prevent dehydration.

After the fasting period, the dog can be gradually fed a easily digestible diet. Suitable foods include cooked rice with chicken or special diet food recommended by the veterinarian. This diet should be continued for a few days before slowly switching back to normal food.

Probiotics or prebiotics can help stabilize the intestinal flora / gut microbiota and restore balance. However, these should only be given after consulting the veterinarian.

It is important to keep the dog in a stress-free environment and allow plenty of rest. Stress can worsen or prolong Diarrhea.

If the diarrhea persists or worsens, the pet owner should not hesitate to consult a veterinarian to ensure appropriate treatment and rule out more serious health problems.

Outlook on current research

Current research into the symptom of Diarrhea in dogs is working intensively to better understand the many causes and mechanisms behind this common problem. Scientists are investigating the role of the microbiome in dogs’ intestinal tract and how changes in the composition of the intestinal flora / gut microbiota can affect Diarrhea. Studies show that a disrupted balance of microorganisms in the gut plays a key role in the development of Diarrhea. This has led to probiotics and prebiotic supplements being researched as potential treatments to stabilize the intestinal flora / gut microbiota.

Another exciting area of research focuses on genetic and immunological factors that may contribute to a dog’s susceptibility to Diarrhea. Some breeds appear more prone to gastrointestinal problems, and researchers are trying to identify genetic markers associated with a higher risk of Diarrhea. At the same time, research is looking at how dogs’ immune system responds to different stimuli and how autoimmune reactions might lead to chronic diarrheal conditions.

Advances in diagnostic technology allow researchers to identify specific pathogens—such as viruses, bacteria, and parasites—more precisely, which can cause Diarrhea in dogs. Modern molecular techniques, including next-generation sequencing, enable faster and more accurate diagnosis of infectious agents, which can lead to more targeted treatment strategies. In addition, new vaccines are being developed to protect dogs from common infectious causes of Diarrhea.

In nutrition research, efforts are underway to develop dietary approaches that can help prevent or reduce Diarrhea in dogs. Specialized diets containing easily digestible ingredients are being tested to assess their effectiveness in easing symptoms and promoting gut health. The impact of fiber and specific fatty acids on intestinal transit and gut health is also being studied to better understand how nutrition can be used strategically to control Diarrhea.

Finally, research is also dedicated to developing new therapeutic approaches, including the use of antidiarrheals specifically formulated for safety and effectiveness in dogs. Innovative approaches such as fecal microbiota transplantation—where healthy gut bacteria are transferred from a donor to a recipient dog to stabilize the intestinal flora / gut microbiota—are also being investigated. These techniques promise to open up a new dimension in the treatment of diarrheal diseases in dogs.

Frequently asked questions

1. What are the most common causes of diarrhea in dogs?
Common causes of Diarrhea in dogs include dietary changes, food intolerances, parasite infestation, bacterial infections, viral infections, stress, foreign bodies in the gastrointestinal tract, and certain medications.
2. When should I take my dog to the vet for diarrhea?
You should see a veterinarian if the diarrhea lasts longer than 24-48 hours, if it is accompanied by vomiting, lethargy, fever, or blood in the stool, or if your dog shows signs of dehydration.
3. What home remedies can help with mild diarrhea?
With mild Diarrhea, it can be helpful to have the dog fast for 12–24 hours to relieve the intestines. After that, a bland diet of cooked chicken and rice can be offered in small portions. Make sure your dog drinks enough water to prevent dehydration.
4. Can stress trigger Diarrhea in dogs?
Yes, stress can lead to Diarrhea in dogs. Changes in the environment, such as moving house or new pets, as well as emotional strain, can affect the gastrointestinal tract and lead to Diarrhea.
5. How can I minimize the risk of diarrhea in my dog?
To minimize the risk of Diarrhea, provide a balanced diet, avoid sudden food changes, keep your pet free of parasites with regular deworming, and prevent your dog from eating spoiled or unsuitable food.
6. Can vaccinations help prevent Diarrhea in dogs?
Vaccinations can help prevent Diarrhea by protecting your dog from certain viral and bacterial infections that can cause Diarrhea, such as distemper or parvovirosis.
7. Is diarrhea in dogs contagious?
Diarrhea itself is not contagious, but its causes can be. If the Diarrhea is caused by a contagious infection such as parvovirosis or Giardia, it can be passed on to other dogs.
8. What role does nutrition play in preventing diarrhea?
Diet plays a key role in preventing Diarrhea. A high-quality, balanced diet supports gut health and helps minimize the risk of diarrheal diseases. Avoid sudden food changes and pay attention to ingredient tolerance.
9. Is it normal for puppies to have diarrhea more often than adult dogs?
Yes, puppies have Diarrhea more often than adult dogs because their immune system is not yet fully developed and they are more susceptible to infections and dietary changes. However, persistent or severe Diarrhea in puppies should be assessed by a veterinarian.
10. Can medications cause diarrhea in dogs?
Yes, certain medications—especially antibiotics—can cause Diarrhea as a side effect because they can disrupt the natural bacterial balance in the gut. Inform your veterinarian if your dog develops Diarrhea after taking medication.