My dog has diarrhoea: causes, home care & when to call the vet
A plain-English guide to diarrhoea in dogs — what\'s usually fine, what isn\'t, and what to do today.
Soft, loose, or watery stool in a dog is one of the most common reasons owners search for vet advice. Most cases resolve within 48 hours with rest and a bland diet — but a meaningful minority signal something serious, and the difference is usually in the details: colour, frequency, the dog's energy, and whether anything else is off.
Bloody diarrhoea, profuse watery diarrhoea, or diarrhoea in a young puppy is never something to wait out. Healthy adult dogs with one soft stool can typically be monitored at home for 24 hours; chronic loose stool (more than 3 weeks) needs investigation regardless of the dog's energy.
Record the colour, consistency, frequency, and anything visible in the stool (blood, mucus, worms, foreign material). That note is what your vet will ask for and is the fastest path to a useful diagnosis.
Common causes
Dietary indiscretion
Monitor at homeGarbage, table scraps, a found item, or a new treat. The most common cause; usually self-limiting.
Food intolerance or allergy
See a vet within 24–48 hoursSpecific protein or carbohydrate triggers chronic soft stool. Diagnosed by an elimination diet trial.
Read more about food intolerance or allergy →Intestinal parasites
See a vet within 24–48 hoursRoundworm, hookworm, whipworm, giardia, coccidia. Especially common in puppies and rescue dogs. Easy faecal test.
Stress colitis
Monitor at homeBoarding, travel, a new home, fireworks. Diarrhoea with mucus or fresh blood streaks, but dog stays bright.
Read more about stress colitis →Bacterial or viral infection
Emergency — vet nowParvovirus, distemper, salmonella, campylobacter. Parvovirus is a life-threatening emergency in young dogs.
Pancreatitis
See a vet within 24–48 hoursOften follows a high-fat meal. Includes vomiting and abdominal pain.
Read more about pancreatitis →Inflammatory bowel disease
See a vet within 24–48 hoursChronic immune-driven gut inflammation. Diagnosed by biopsy. Managed with diet and medication.
Read more about inflammatory bowel disease →What you can safely do at home
- Withhold food for 12 hours (adult dogs only). Allow free access to water.
- Offer bland diet: boiled chicken breast and plain white rice, 1 part chicken to 2 parts rice, small frequent meals.
- A teaspoon of plain pumpkin puree (not pie filling) per 10kg body weight can firm up stool.
- Transition back to regular food over 3 days.
- Probiotic paste designed for dogs (FortiFlora, ProKolin) can shorten recovery.
- If diarrhoea persists past 48 hours despite bland diet, see a vet rather than continuing to wait.
These steps are general guidance for an otherwise well, healthy adult pet. If your dog is a puppy/kitten, a senior, or has a known chronic condition, call a vet rather than waiting it out.
What to expect at the vet
The vet will usually:
- Faecal sample test for parasites and giardia
- Parvovirus snap test if a puppy or unvaccinated adult
- Bloodwork to rule out pancreatitis and check hydration
- Anti-diarrhoeal medication, anti-nausea, and possibly antibiotics if bacterial cause suspected
- IV fluids if dehydrated
Useful questions to ask:
- Do we need a parvo or giardia test before sending us home?
- Should I bring a faecal sample to the next visit?
- What's the threshold for coming back?
- When can we return to normal food?
- If this becomes chronic, what next?
How to reduce the chance of it happening again
- Year-round intestinal worming on a vet-recommended schedule.
- Slow transitions between foods over 7 days.
- Keep human food, garbage, and compost out of reach.
- Maintain parvovirus vaccinations.
- Avoid letting your dog drink from puddles, ponds, or shared water bowls at dog parks.
Frequently asked questions
How long does normal "garbage gut" diarrhoea take to resolve?
24–48 hours with bland diet, rest, and good hydration. If it continues past 48 hours, see a vet.
Is one bloody streak in the stool an emergency?
A single small streak in an otherwise bright dog with stress colitis is usually manageable at home for 24 hours. Continuous fresh blood, or any black tarry stool, needs a same-day vet visit.
Can I give Imodium to my dog?
Never without a vet's direction. Imodium is dangerous for herding breeds (Collies, Australian Shepherds) with the MDR1 gene mutation and can mask serious conditions.
What's the difference between large- and small-bowel diarrhoea?
Large-bowel: small amounts, frequent urgency, mucus, fresh red blood. Small-bowel: large volumes, less frequent, sometimes black tarry, may include weight loss. Telling your vet which pattern fits speeds diagnosis.
Should I feed my puppy through diarrhoea?
Yes — never withhold food from puppies; they can become hypoglycaemic. Use a bland diet in small frequent meals and call a vet the same day.