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Puppy Diarrhea and Vomiting: What to Do and When to Call the Vet

By Adrian Furletti, Founder & Editor · Reviewed by the PawSmart editorial team · Updated 2026-07-02 · How we research

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An upset tummy is one of the most common reasons new owners panic in their puppy's first weeks at home. A single soft stool or one bout of vomiting in a puppy who is otherwise bright, playful and drinking is often minor. But puppies are not small adult dogs — they have tiny reserves and dehydrate dangerously fast, and some causes of vomiting and diarrhea (like parvovirus or a swallowed toxin) can become life-threatening in hours. This guide explains the common causes, the red-flag signs that mean call your vet right now, and how to care for a mild, single upset at home. When in doubt with a puppy, err on the side of calling.

Common causes of puppy vomiting and diarrhea

• Diet change: Switching food too quickly is a very common trigger. New foods should be introduced gradually over about a week, mixing more of the new in with the old each day.
• Dietary indiscretion: Puppies explore with their mouths and eat things they shouldn't — table scraps, rich treats, grass, sticks, garbage. This "garbage gut" often causes a short-lived upset.
• Stress: Going to a new home, travel, weaning and other big changes can cause soft stools in an otherwise healthy puppy.
• Parasites: Intestinal worms and protozoa such as giardia and coccidia are very common in puppies and a frequent cause of persistent diarrhea. This is one reason routine deworming matters.
• Infections: Viral and bacterial infections — most seriously parvovirus in under-vaccinated puppies — can cause severe vomiting and diarrhea and are medical emergencies.
• Toxins and foreign objects: Human medicines, chocolate, xylitol, grapes, certain plants and cleaning products are all dangerous, and a swallowed toy or sock can cause a blockage. Any suspected toxin or blockage is an emergency.

Red flags: call or see a vet now

Contact your vet or an emergency clinic straight away if your puppy shows any of the following. With a young puppy, one of these is enough — you do not need to wait for several.

• Blood in vomit or stool (fresh red, or dark/tarry material that looks like coffee grounds).
• Repeated vomiting — more than once or twice, or vomiting that keeps coming back.
• Can't keep water down — vomiting up every drink, which leads to fast dehydration.
• Lethargy, weakness or collapse — a puppy who is flat, unresponsive or not their usual self.
• Suspected parvo — an unvaccinated or partly vaccinated puppy with vomiting, foul or bloody diarrhea and loss of appetite.
• Suspected toxin or a swallowed object — any chance they ate something poisonous or a foreign object.
• Very young, very small or "toy" breed puppies — they have almost no reserves and dehydrate and drop their blood sugar dangerously fast, so lower your threshold to call.
• Pale, white or tacky gums, a bloated or painful belly, a fever, or signs of dehydration (skin that stays tented, dry gums, sunken eyes).
• Symptoms lasting more than about 24 hours, or getting worse rather than better.

Safe at-home care for a mild, single upset

The steps below are only for a puppy who has had one episode of vomiting or a single bout of soft stool, is bright, alert and playful, has normal gums, and is keeping water down — with none of the red flags above. If you are unsure, treat it as a "call the vet" situation instead.

• Go easy on food briefly — but don't fast a young puppy for long. Adult dogs are sometimes rested from food for a short vet-guided period, but puppies can crash their blood sugar if they go without food, so any short pause should be brief and only on your vet's advice. When unsure, feed a small bland meal rather than fasting.
• Offer a bland diet. Small, frequent meals of plain boiled chicken (no skin, bones or seasoning) with white rice or plain pumpkin are gentle on the gut. Feed little and often for a day or two.
• Keep them hydrated. Offer small amounts of fresh water frequently. Puppies dehydrate quickly, so watch that they are drinking and keeping it down — if they can't, that's a red flag.
• Reintroduce normal food gradually. Once stools firm up, mix their regular food back in over a couple of days rather than switching all at once.
• Rest and watch closely. Keep them calm, note the number and look of episodes, and check gums and energy. If anything worsens or a red flag appears, stop and call your vet.
• Do not give human medicines. Many over-the-counter anti-diarrheal and anti-nausea drugs are unsafe or wrongly dosed for puppies. Only give medication your vet has recommended for your specific puppy.

Throughout, remember that puppies are higher-risk than adult dogs. What might be a "wait and see" upset in a healthy adult can become serious quickly in a puppy. If home care doesn't clearly improve things within a few hours, or you have any doubt at all, call your vet.

The bottom line

A single soft stool or one vomit in a bright, playful, well-hydrated puppy is often minor and can be managed with a bland diet, careful hydration and close watching. But blood, repeated vomiting, lethargy, an inability to keep water down, suspected parvo or toxins, pale gums, or a very young or tiny puppy all mean it's time to call the vet now. When you're weighing it up, err toward calling — with puppies, an early phone call is always cheaper and safer than waiting.

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