Why Does My Dog Have Diarrhoea?

Watching your dog experience discomfort, especially with symptoms like diarrhoea, can be concerning for any pet parent. Diarrhoea is a common issue in dogs and can have a wide range of causes, from minor dietary mishaps to serious underlying health problems. Understanding the potential reasons behind your dog’s upset stomach can help you take the right steps to ensure their health and well-being.

In this article, we’ll explore the causes of diarrhoea in dogs, the symptoms that require closer monitoring, and the best ways to manage and prevent it. 

What Is Diarrhoea in Dogs?

Diarrhoea is defined as an increase in stool looseness or frequency, often resulting in watery or soft stools. It is not a disease but rather a symptom of an underlying issue. The gastrointestinal (GI) tract may become upset for various reasons, leading to diarrhoea.

While an occasional bout of diarrhoea might not be serious, prolonged or severe episodes can result in dehydration, nutritional deficiencies, or even life-threatening complications. Puppies, senior dogs, and those with existing health conditions are particularly vulnerable to the effects of diarrhoea.

Understanding what may have triggered your dog’s upset stomach and knowing when to seek veterinary care are vital steps in managing the condition.

Common Causes of Diarrhoea in Dogs

Dietary Indiscretion (Eating Something They Shouldn’t)

Dogs are naturally curious and often eat things they shouldn’t, such as spoiled food, rubbish, or non-food items like toys and socks. These items can irritate the digestive system and lead to diarrhoea.

Sudden Diet Changes

Switching your dog’s food abruptly is a common cause of digestive upset. A sudden change doesn’t allow the gastrointestinal system to adapt, resulting in diarrhoea. A gradual transition over 7 to 10 days is essential when introducing a new diet.

Food Intolerances or Allergies

Dogs can develop food intolerances or allergies, with common triggers including dairy, wheat, and certain proteins. These can lead to chronic or intermittent diarrhoea.

Parasites

Intestinal parasites like roundworms, hookworms, whipworms, and giardia are frequent causes of diarrhoea, especially in puppies or dogs not on a regular deworming schedule. Parasite infestations can also lead to weight loss and a dull coat.

Infections
Diarrhoea in dogs can result from both bacterial and viral infections. Bacterial infections, such as those caused by Salmonella, can upset the digestive system and lead to severe symptoms. Viral infections, including Parvovirus, are highly contagious and particularly dangerous for puppies and unvaccinated dogs, often requiring immediate veterinary care.

Stress or Anxiety

Stress-related diarrhoea, also known as stress colitis, is common in dogs experiencing changes in their environment or routine. Events like moving house, introducing a new pet, or loud noises such as fireworks can trigger diarrhoea.

Toxins or Poisoning

Ingesting toxic substances such as certain plants, medications, chocolate, or cleaning products can lead to diarrhoea as the body attempts to expel the harmful material. Other symptoms may include vomiting, lethargy, or seizures.

Chronic Diseases

Conditions like inflammatory bowel disease (IBD), pancreatitis, or liver and kidney diseases can cause recurrent or chronic diarrhoea. These require long-term management under veterinary supervision.

Medication Side Effects

Certain medications, such as antibiotics or non-steroidal anti-inflammatory drugs (NSAIDs), may upset your dog’s stomach and lead to diarrhoea. Always inform your vet if diarrhoea develops after starting a new medication.

Underlying Medical Conditions

Endocrine disorders, such as hypothyroidism or Addison’s disease, can contribute to gastrointestinal issues. Dogs with these conditions may experience other symptoms, such as weight changes or lethargy.

Symptoms to Watch For

While mild diarrhoea may resolve on its own, certain symptoms indicate a more serious issue:

• Frequent diarrhoea lasting more than 48 hours
• Bloody or black tarry stools, which could indicate internal bleeding
• Vomiting, particularly alongside diarrhoea
• Lethargy or noticeable lack of energy
• Dehydration, evidenced by dry gums, sunken eyes, or poor skin elasticity
• Loss of appetite
• Fever or elevated body temperature
• Straining or discomfort when defecating

If your dog displays any of these symptoms, contact your vet promptly to determine the underlying cause and begin appropriate treatment.

When to See a Vet

Veterinary care is crucial if:

• Your dog is a puppy, senior, or has pre-existing health conditions
• Diarrhoea is severe, bloody, or black
• Your dog shows signs of vomiting, lethargy, or dehydration
• Symptoms persist for more than 48 hours
• You suspect your dog has ingested something toxic

Prompt treatment can prevent complications and ensure the best outcome for your dog.

What to Do if Your Dog Has Diarrhoea

1. Assess the Situation
   Look for potential causes of diarrhoea, such as recent dietary changes, access to rubbish, or ingestion of toxic substances. Identifying possible triggers can help you manage the issue or provide helpful information to your vet if needed. If there are no obvious signs of severe illness, you may choose to monitor your dog’s condition at home while keeping a close eye on their symptoms.
2. Provide Hydration
   Diarrhoea can quickly lead to dehydration, so ensure your dog has access to clean, fresh water at all times. Important to monitor their hydration signs to ensure they are getting enough water. 
3. Withhold Food for 12–24 Hours (Optional)
   For healthy adult dogs, withholding food for 12–24 hours may help settle their digestive system. This step is not recommended for puppies, senior dogs, small breeds, or dogs with certain health conditions, as fasting can be harmful to these groups.
4. Feed a Bland Diet
   Offering small, frequent meals of a bland diet, such as boiled chicken and rice or plain boiled pumpkin can be a good gentle option for the stomach. Stick to this diet for 2 to 3 days before gradually transitioning back to your dog’s regular food.
5. Monitor Their Symptoms
   Keep a close eye on your dog’s stool consistency, frequency, and overall behaviour. If diarrhoea persists beyond 48 hours or if your dog starts showing other symptoms like lethargy, vomiting, or loss of appetite, contact your vet promptly.

Preventing Diarrhoea in Dogs

• Maintain a Consistent Diet - Avoid sudden changes to your dog’s diet. Introduce new foods gradually to allow their digestive system to adjust.
• Supervise What They Eat - Keep your dog away from rubbish, animal droppings, and non-food items. Use pet-proof bins and secure storage for household items.
• Regular Deworming and Vaccinations - Follow your vet’s recommendations for deworming and vaccinations to prevent parasites and infectious diseases.
• Clean Food and Water Bowls - Wash your dog’s bowls regularly to minimise bacterial contamination.
• Avoid Overfeeding or Rich Foods - Table scraps, fatty foods, and large meals can upset your dog’s stomach and should be avoided.
• Minimise Stress - Create a calm, consistent environment and maintain a predictable routine to reduce stress-related diarrhoea.
• Routine Vet Check-ups - Regular health checks help detect and address underlying conditions early, keeping your dog’s digestive system healthy.

Final Thoughts

Diarrhoea in dogs is often manageable with proper care and attention. Mild cases typically resolve with simple interventions like fasting, hydration, and a bland diet. However, severe or prolonged diarrhoea requires prompt veterinary attention to prevent complications like dehydration or nutrient loss.

By taking preventative steps such as maintaining a consistent diet, regular deworming, and managing stress you can help your dog avoid gastrointestinal upsets. If you’re ever unsure or concerned about your dog’s health, consult your veterinarian.