Dog diarrhea: causes, home care and when to worry

Dog diarrhea is one of the most common reasons people call the vet, and most of the time it clears up in a day or two. Your dog raided the trash at a cookout, you switched foods too quickly, or a weekend at the boarding kennel left them a little stressed. But the same loose stool can also be the first sign of a serious infection, a poisoning or a chronic gut problem.

The trick is knowing which signs to watch. This guide explains what the color and texture of your dog’s poop can tell you, the most common causes, how to check for dehydration, what you can safely do at home without medication, and when waiting is a bad idea.

Types of diarrhea in dogs: acute vs. chronic, small vs. large bowel

Vets sort diarrhea in two ways, and figuring out which type your dog has helps narrow down the cause.

By duration, diarrhea is either acute, starting suddenly and lasting a few days, or chronic, lasting more than two or three weeks or coming and going for months. Acute diarrhea usually has a short-lived cause; chronic diarrhea almost always needs a proper workup.

By where it starts, the stool and your dog’s behavior look quite different:

Also notice how your dog acts between trips outside. A dog with stress colitis may be bouncing around the yard, while a dog with an intestinal infection is usually quiet and off their food.

What your dog’s poop color and texture mean

Healthy stool is brown, formed, firm and easy to pick up. When something changes, the look of it gives you clues:

Common causes of diarrhea in dogs

• Diet: garbage, table scraps, a sudden food change, too many treats, fatty foods, or milk in dogs that don’t digest lactose well. To avoid trouble when changing foods, follow our steps on how to switch dog food.
• Intestinal parasites: giardia, coccidia, roundworms, hookworms and whipworms. They’re especially common in puppies and in dogs who visit dog parks or daycare. Check how often to deworm a dog based on your dog’s lifestyle.
• Infections: viruses like parvovirus or distemper, and bacteria such as Salmonella or Campylobacter.
• Stress: travel, a move, boarding or a new baby can trigger stress colitis, with soft stool and mucus.
• Poisoning: plants, cleaning products, toxic foods or medications.
• Food allergies and intolerances, which tend to cause chronic or on-and-off diarrhea, sometimes with itchy skin.
• Digestive and other diseases: pancreatitis, inflammatory bowel disease, exocrine pancreatic insufficiency, liver or kidney disease, Addison’s disease or intestinal tumors.
• Medications, especially some antibiotics and anti-inflammatories.

When dog diarrhea is an emergency

Small breeds such as Yorkshire terriers, toy poodles, miniature schnauzers and Maltese are more prone to acute hemorrhagic diarrhea syndrome: sudden, very bloody diarrhea, often with vomiting, that can dehydrate a dog within hours. With prompt treatment, most dogs recover well.

How to tell if your dog is dehydrated

Dehydration is the main danger of severe diarrhea. You can do three quick checks at home:

1. Skin tent test. Gently pinch the skin between the shoulder blades and let go. In a well-hydrated dog it springs back almost instantly; if it’s slow or stays tented, your dog is low on fluids.
2. Gums. They should be pink and moist. Dry, tacky or pale gums are a red flag.
3. Capillary refill time. Press a fingertip on the gum until it turns white, then release. The pink color should return in under 2 seconds.

The skin test is less reliable in senior or very thin dogs, because skin loses elasticity with age. If you’re not sure, our dog first aid guide shows how to check basic vital signs.

What to do at home for dog diarrhea

These steps are for an adult dog who is alert, eating and drinking, and who has none of the warning signs above.

1. Keep fresh water available at all times. Set out extra bowls if needed and refresh them often. If your dog won’t drink, call your vet.
2. Skip long fasts. Many vets no longer recommend withholding food for long periods, because the gut heals better with nutrition. If your dog has also vomited, a few hours of rest can help (see what to do when your dog is vomiting), but don’t fast a puppy without your vet’s advice.
3. Switch to a bland diet in 3–4 small meals a day for 2–3 days. Our guide to the bland diet for dogs covers ingredients and portions.
4. Ease back to regular food over 3–5 days, mixing it with the bland diet once the stool starts to firm up.
5. No treats, chews or table scraps while the diarrhea lasts.
6. Take more frequent, shorter potty breaks so your dog can go when needed and you can see how the stool is changing.

Veterinary probiotics may shorten some bouts of acute diarrhea, although the evidence is moderate. Ask your vet whether one makes sense for your dog before buying anything.

What your vet will do

Besides a physical exam and a hydration check, your vet will likely run a fecal test to look for parasites, a giardia or parvo test depending on the case, and blood work if your dog is lethargic. X-rays or ultrasound are used when a foreign object, pancreatitis or another abdominal problem is suspected.

Treatment depends on the cause: fluids for dehydration, dewormers when parasites show up, a prescription GI diet and, in severe cases, hospitalization. Antibiotics are no longer given routinely for uncomplicated acute diarrhea; vets save them for specific situations.

Chronic diarrhea calls for a broader workup: complete blood work, pancreatic function tests, an elimination diet with a hydrolyzed or novel protein for several weeks and, in some cases, endoscopy with biopsies.

Diarrhea in puppies: why you should act sooner

Puppies have much smaller reserves of water and blood sugar than adults, so diarrhea that would be a nuisance in a 55-lb (25-kg) dog can dehydrate a 7-lb (3-kg) puppy in a matter of hours. Puppies are also more vulnerable to parasites like giardia and coccidia and to viral infections.

Slightly soft stool during the first few days in a new home is common, thanks to stress and a new food. But if the diarrhea is watery or bloody, or your puppy is vomiting or lethargic, call your vet right away. If your puppy hasn’t finished their vaccines, keep them away from other dogs until they’ve been seen.

How to prevent diarrhea in dogs

• Change foods gradually, over 7–10 days.
• Go easy on treats: they shouldn’t make up more than 10% of daily calories.
• Secure the trash and keep risky foods out of reach; watch what your dog picks up on walks.
• Deworm regularly and run fecal tests as often as your vet recommends.
• Keep vaccines up to date, especially in puppies.
• Offer clean water: don’t let your dog drink from puddles or stagnant ponds, where giardia and leptospira can live.
• Keep routines steady and prepare ahead for travel or big changes if your dog has a sensitive stomach.

Frequently asked questions

Can I give my dog rice or pumpkin for diarrhea?

Plain, well-cooked white rice is part of the classic bland diet because it’s easy to digest, though on its own it isn’t a complete meal; pair it with a lean protein like boiled skinless chicken, with no salt, oil or seasoning. Plain canned pumpkin (not pie filling) is a popular fiber add-in, but the evidence behind it is limited and it won’t fix an infection.

Why does my dog have diarrhea with mucus?

Mucus means the large intestine is irritated. Stress, a diet change, parasites such as whipworms or a food intolerance can all cause it. If your dog is acting normal and the mucus clears up in a day or two, it usually isn’t serious. If it keeps happening, blood shows up, or your dog strains constantly, ask your vet for a fecal test.

Is diarrhea normal after deworming a dog?

Some dogs have slightly soft stool for a day or two after a dewormer, and puppies with heavy worm loads may pass visible worms. If the diarrhea is severe, lasts more than 48 hours or comes with vomiting or lethargy, call your vet so they can decide whether it’s a reaction to the medication or a separate problem.

How long does diarrhea last in dogs?

Mild acute diarrhea usually improves within 24–72 hours on a bland diet. If there’s no improvement at all after 48 hours, call your vet even if your dog seems fine. When diarrhea lasts longer than two or three weeks, or keeps coming and going, it’s considered chronic and needs testing to find the underlying cause.

Can dog diarrhea spread to other dogs or to people?

It depends on the cause. Parvovirus, giardia and some parasites spread easily between dogs, and bacteria such as Salmonella or Campylobacter can pass to people. Always pick up the poop, wash your hands well, clean soiled areas and keep your dog away from other dogs until your vet rules out a contagious infection.

Sources

• Merck Veterinary Manual: diarrhea and intestinal diseases in dogs.
• Companion Animal Parasite Council (CAPC): guidelines on intestinal parasites and giardia in dogs.
• PDSA: guidance on diarrhea in dogs and when to see a vet.
• American Kennel Club (AKC): causes of dog diarrhea and basic care.