What Causes Diarrhoea in Dogs and What Should You Feed Them?

At a glance

• The most common causes are dietary change, scavenging, stress, parasites, and food intolerance
• Most uncomplicated cases resolve within 24–48 hours with bland food and hydration
• Withholding food entirely is no longer recommended — small, frequent, easily digestible meals are better
• Persistent, bloody, or severe diarrhoea always warrants a vet visit
• Once recovered, a consistent, high-quality diet supports long-term gut stability

Why do dogs get diarrhoea?

Diarrhoea in dogs is extremely common, and most of the time it has a straightforward cause. The gut is surprisingly good at signalling when something is wrong, and loose stools are one of its most direct messages.

The most frequent triggers are:

• A sudden switch in food — the gut microbiome (the community of bacteria living in the digestive tract) needs time to adjust to new ingredients
• Scavenging or eating something inappropriate — rubbish, grass, fatty scraps, or something rotten
• Stress — kennels, fireworks, a new home, or any significant change in routine
• Intestinal parasites — roundworm, giardia, and other parasites are a common cause in puppies especially
• Food intolerance or sensitivity — some dogs react to specific proteins or ingredients with ongoing digestive upset
• Viral or bacterial infection — less common but more serious, and more likely if other dogs in the household are affected
• Certain medications — antibiotics in particular can disrupt the gut

For most healthy adult dogs, a single episode of loose stools with no blood, no vomiting, and normal energy levels is not an emergency. It is worth monitoring for 24–48 hours before deciding whether a vet visit is needed.

If your dog is passing blood, vomiting repeatedly, seems lethargic or in pain, or the diarrhoea lasts longer than 48 hours, get them seen by a vet. Puppies and elderly dogs need veterinary attention sooner rather than later, as they dehydrate more quickly. Digestive upset is one of several common conditions where diet plays a direct role in your dog's health, and understanding that connection helps you respond more effectively.

What should you feed a dog with diarrhoea?

The old advice was to starve a dog for 24 hours and then reintroduce food slowly. Most vets now recommend against withholding food entirely. The gut lining needs nutrients to repair itself, and fasting can prolong recovery rather than speed it up.

Instead, feed small, frequent meals of bland, easily digestible food for 48–72 hours. The goal is to give the gut a break from anything hard to process while still providing the nutrition it needs to recover.

Good bland options include:

• Plain boiled chicken breast (no skin, no seasoning) with plain white rice
• Plain boiled white fish with white rice
• Plain cooked sweet potato or pumpkin — both are gentle on the gut and provide soluble fibre, which helps firm up stools
• A small amount of plain, full-fat yoghurt — this provides live cultures (beneficial bacteria) that can support gut recovery

Keep portions small — roughly half your dog's normal meal size, fed three or four times through the day rather than two larger portions. Fresh water must always be available. Diarrhoea causes fluid loss quickly, and dehydration becomes a risk if water intake drops.

Avoid anything fatty, rich, or heavily seasoned. Dairy beyond a small amount of yoghurt is not helpful. Treats, chews, and table scraps should stop until the gut has settled.

Should you use probiotics or supplements?

Probiotics — live beneficial bacteria — have solid evidence behind them for shortening the duration of acute diarrhoea in dogs. They work by restoring balance to the gut microbiome when it has been disrupted.

A targeted gut health supplement designed specifically for dogs is the most reliable way to deliver the right strains at the right dose. Not all human probiotic products are appropriate for dogs, and the bacterial strains matter. Prebiotics — dietary fibres that feed the beneficial bacteria — work alongside probiotics and are worth including too. Chicory root is one of the best-researched prebiotic fibres for dogs, and understanding how chicory root supports the gut microbiome explains why it appears in a growing number of quality dog foods.

Supplements are supportive tools during recovery, not a substitute for addressing the underlying cause. If your dog is getting repeated bouts of diarrhoea, a supplement alone will not solve it.

What should you feed long-term to prevent diarrhoea coming back?

Repeated diarrhoea is often a sign that something in the regular diet is not working. The most productive place to start is the food itself.

Heavily processed foods with high levels of fillers, synthetic additives, and low-quality protein sources are harder for sensitive guts to handle. Fresh food is significantly easier for dogs to digest than heavily processed kibble, and for dogs with recurring digestive issues, the switch alone makes a meaningful difference for many owners.

If food intolerance is suspected, a novel protein — one your dog has never eaten before — is often the best place to start. Lamb is a useful option here, as it is less common in standard dog foods and therefore less likely to be the source of an existing reaction. Marleybones' Lush Lamb is a single-protein recipe with no fillers, which makes it straightforward to use in a dietary trial.

If you are switching foods to help settle a sensitive gut, always transition gradually over 7–10 days. A sudden switch is itself a common cause of diarrhoea, so a slow transition gives the gut time to adjust without triggering another episode. There is clear guidance on how to transition your dog to a new food without upsetting their stomach.

Consistency matters more than most owners realise. Dogs that eat the same quality food day to day, with minimal variation in treats and scraps, have more stable guts. The microbiome thrives on routine.

Every dog is different — build your personalised Marleybones feeding and health plan tailored to your dog's age, size, and health requirements.

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FAQs

How long does diarrhoea in dogs normally last?

Most uncomplicated cases resolve within 24–48 hours with bland food and adequate water. If diarrhoea continues beyond 48 hours, or gets worse rather than better, a vet appointment is warranted.

Should I stop all food if my dog has diarrhoea?

No. Current guidance is to continue feeding small amounts of bland, easily digestible food. Fasting is not recommended as the gut lining needs nutrients to repair. Reduce portion size and increase meal frequency instead.

What foods should I avoid giving a dog with diarrhoea?

Avoid fatty foods, rich or heavily seasoned meals, large amounts of dairy, treats, and table scraps until the gut has settled. These all put additional demand on a digestive system that is already struggling.

Can stress cause diarrhoea in dogs?

Yes. Stress is a well-established trigger for digestive upset in dogs. Fireworks, travel, kennels, a new home, or changes in household routine can all cause loose stools, even in dogs with no underlying gut issues. The gut and the nervous system are closely connected.

When should I take my dog to the vet for diarrhoea?

See a vet if there is blood in the stool, if vomiting accompanies the diarrhoea, if your dog is lethargic or clearly in pain, if diarrhoea has not improved after 48 hours, or if your dog is a puppy or a senior. Both groups dehydrate faster and need prompt attention.

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