Wondering why your dog has the runs? Read on to find out the common causes of diarrhoea, when you should take your dog to the vet, and how you can help manage your dog’s diarrhoea at home.

What is diarrhoea? 

Diarrhoea is a common condition that can cause concern for pet owners. It is characterised by loose or liquid stools 

Affected animals may also be going to the toilet more frequently than normal, straining excessively when trying to defecate, or even passing blood or mucous in their faeces. The severity of diarrhoea can vary from mild and self-limiting to severe and potentially life-threatening. 

Causes of diarrhoea in dogs 

Diarrhoea is a sign that the digestive system is not functioning normally and can be caused by a variety of factors. 

Dogs may experience diarrhoea due to: 

  • Dietary indiscretion or diet changes: Any sudden change in the diet can disrupt the gut flora. 
  • Ingesting Spoiled Food: Eating garbage or spoiled food can lead to gastrointestinal upset. 
  • Stress: Changes in environment or routine can cause stress-related diarrhoea. 
  • Infections: Viral, bacterial, or parasitic infections can all lead to diarrhoea. 
  • Inflammatory Diseases: Conditions like inflammatory bowel disease, pancreatitis or even food allergies can cause diarrhoea. 
  • Hormonal conditions: Conditions such as diabetes or hyperthyroidism may be associated with diarrhoea. 
  • Organ dysfunction: Abnormalities with the function of different organs such as the liver or kidneys may trigger diarrhoea. 
  • Medications: Some medications can disrupt normal gut function. 


When to take your dog to the vet  

It’s crucial to know when diarrhoea is an emergency. You should take your dog to the vet if: 

  • The diarrhoea lasts more than two days 
  • They are not eating or drinking normally 
  • They are also vomiting repeatedly 
  • They are no longer acting like their normal self (e.g. they’re lethargic) 
  • They start passing lots of fresh red or tarry black blood in their stool 
  • They are very young, very old, or have a pre-existing health condition 
  • Their symptoms coincide with starting a new medication 



How to manage your dog’s diarrhoea at home 

For mild cases, there are a few things you can do to help manage your dog’s diarrhoea at home. 

Provide a balanced, age-appropriate gastrointestinal support diet 

It is best to contact your regular vet to discuss which diet would be the most appropriate for your dog. There are many commercially available, nutritionally balanced, gastrointestinal support diets.  

Your vet may also recommend a different diet type if they suspect a particular medical condition (such as a food allergy) or a bland, home-cooked diet for short-term feeding (these bland diets are not usually nutritionally balanced). 

Make sure your dog stays hydrated 

Your dog will be losing water through diarrhoea and are at risk of becoming dehydrated. Make sure they have plenty of access to fresh, clean water. If you’re concerned they’re not drinking enough water to keep up with their losses, take them to your vet.  

Add probiotics to your dog’s diet 

Adding probiotics into your dog’s diet can help restore a healthy gut flora. They’re available in liquids or powders that you can mix into your dog’s food daily.  

Closely monitor their symptoms 

If your dog’s symptoms persist for more than a couple of days or worsen, seek veterinary care immediately. If possible, try to take a fresh stool sample to your dog’s appointment as it could help your veterinarian diagnose the cause of their diarrhoea. 

How to prevent diarrhoea in dogs 

Preventative measures include: 


While diarrhoea can often be self-limiting and may be managed at home, it’s important to monitor your dog’s condition closely and consult with a vet if you have any concerns or if your dog is not improving quickly. Your vet can provide a tailored approach to treatment based on your dog’s specific needs and health status.