Loose Stools: What Causes Diarrhoea in Dogs and When to Worry

In this guide

Diarrhoea is one of the most common reasons dog owners seek advice, and for good reason, the causes range from a harmless dietary indiscretion to something that needs urgent care.

Common causes

• Dietary indiscretion, eating something unusual, spoiled, or rich, very common in dogs that scavenge on walks
• Sudden diet changes, without a gradual transition
• Intestinal parasites, including worms and protozoa such as Giardia, common given India's street dog population and shared outdoor spaces
• Viral or bacterial infections, including parvovirus in unvaccinated puppies, a genuine emergency
• Food intolerance or allergy
• Stress or anxiety, from travel, boarding, or a change in household routine
• Underlying disease such as inflammatory bowel disease, pancreatitis, or organ dysfunction in chronic cases

When it is likely mild

A single episode of soft stool in an otherwise bright, eating, drinking dog, without blood, vomiting, or lethargy, often resolves within a day or two with a bland diet of boiled chicken and rice in small portions, and access to plenty of water.

When it is an emergency, especially in puppies

• Diarrhoea with blood, whether bright red or dark and tarry
• Repeated vomiting alongside diarrhoea
• Lethargy, weakness, or a dog that seems to be deteriorating rather than improving
• Any diarrhoea in an unvaccinated puppy, given the real risk of parvovirus, which can be fatal within days without treatment
• Diarrhoea lasting more than two to three days despite home care
• Visible dehydration: sunken eyes, dry gums, or skin that is slow to spring back when gently pinched

A practical note for India

Given the prevalence of intestinal parasites, a fresh stool sample test is often one of the most useful first steps a vet can run for recurrent or unexplained diarrhoea, and keeping deworming on a regular schedule, discussed with your vet, meaningfully reduces how often this comes up in the first place.

Common Questions

Q: Is fasting still recommended for a dog with diarrhoea? A: Current guidance generally favours small, frequent bland meals over withholding food entirely, since fasting is no longer considered necessary or beneficial in most cases.

Q: Can probiotics help with diarrhoea? A: Yes, they are often recommended alongside supportive care for mild, uncomplicated cases to help restore normal gut bacteria balance.

Article content © S Vejay Anand. All rights reserved.