Quick answer: A dog with both vomiting and diarrhea can dehydrate quickly. A mild, short episode in a healthy adult dog may settle within a day or two, but puppies, small dogs, seniors, and any dog with blood, weakness, or ongoing symptoms should see a vet promptly. Call if you are unsure.
Few things send a dog owner scrambling like a dog who is throwing up and has diarrhea at the same time, often at night. Many cases come from something simple, like a dietary slip, but the combination can also signal infection or something more serious. This guide walks through a timeline, a dehydration check, and the points where it is time to call. For the full symptom overview, see our dog vomiting and diarrhea guide.
Call your vet now if your dog has any of these
- A puppy, a senior dog, a toy breed, or a dog with a health condition such as diabetes, kidney disease, or heart disease
- An unvaccinated or partly vaccinated puppy (parvovirus is a concern)
- Blood in the vomit or stool, black or tarry stool, or vomit that looks like coffee grounds
- Repeated vomiting, or vomiting and diarrhea lasting longer than 24 hours
- Lethargy, weakness, fever, or belly pain
- Dry, sticky, or pale gums, or a dog who will not drink
- A swollen belly or unproductive retching
- Any chance your dog swallowed a toy, sock, bone, plant, medication, or something toxic
If you think your dog ate something poisonous, call your vet or the ASPCA Animal Poison Control Center immediately. The American Kennel Club, citing an emergency veterinarian, advises an emergency visit when diarrhea comes with vomiting, lack of appetite, or significant lethargy. When in doubt, call.
Why dogs get vomiting and diarrhea together
Vomiting and diarrhea are signs, not diagnoses. When they arrive together, the gut is usually irritated from top to bottom. The VCA overview of gastroenteritis in dogs describes it as inflammation of the stomach and intestines that can be caused by infection, medications, or even new foods, and it says most affected dogs have intermittent vomiting and diarrhea, lower energy, and a reduced appetite.
Common reasons include:
- Dietary indiscretion. Garbage, table scraps, spoiled food, and rich treats.
- A fast diet change. The AKC lists switching foods too quickly as a cause of diarrhea.
- Stress. Travel, boarding, or changes at home can upset a dog's digestion.
- Parasites and infections. Worms, giardia, bacteria, and viruses such as parvovirus.
- Toxins and foreign objects. Plants, chemicals, string, or toys.
- More serious illness. Pancreatitis, kidney or liver disease, and other conditions.
VCA also notes that gastroenteritis is a diagnosis of exclusion, which means your vet needs to rule out more serious causes first. You cannot tell the cause from the stool alone, which is another reason to lean toward calling.
A simple timeline: what to do and when
Hour 0 to 6: observe and protect
Check your dog's alertness and look through the red-flag list. Pick up any chewed items or suspect foods so there is no second round. Offer small amounts of fresh water. The Merck Veterinary Manual says water should not be withheld from a vomiting dog unless a vet is giving fluids, since fluid loss makes everything worse. Take a phone photo of the vomit and stool, and note the times. Your vet will ask.
The rest of the first day: small steps
If your dog is a healthy adult, bright, and has vomited once or twice, vets often suggest a short pause from food, then small portions of bland food once the vomiting has stopped. VCA says in otherwise healthy adult dogs, your vet may advise withholding food for a short time or feeding small amounts of a veterinary gastrointestinal diet. The length of the pause varies, so ask your vet, and do not fast puppies, toy breeds, or diabetic dogs without veterinary advice. Do not give human medications to try to stop the signs. The AKC cites an emergency veterinarian who says most human medications are ineffective and some can be harmful.
Day 2 to 3: reassess
VCA advises consulting your veterinarian if frequent liquid or semi-liquid stools persist for more than two days, and says vomiting that continues for more than one to two days in an otherwise well dog calls for veterinary care. If your dog is improving, eating a little, and drinking normally, you are on the right track. If anything is getting worse, or your dog has stopped drinking, do not wait.
Any time: the point where it becomes an emergency
Blood, black stool, collapse, a hard or swollen belly, unproductive retching, or a puppy who seems flat all call for an immediate visit. Do not wait for a "better" time of day.
How to check for dehydration
Vomiting and diarrhea together drain fluid fast. VCA notes that dehydration can occur quickly if the signs continue for more than 24 hours. The AKC lists these signs of dehydration in dogs:
- Dry or sticky gums
- Thick saliva
- A dry nose
- Excess panting
- Lack of energy
- Loss of appetite
A simple check: lift your dog's lip and touch the gums with a clean finger. They should feel wet and slippery. Tacky, dry gums are a reason to call your vet. A dehydrated dog may refuse to drink, and dogs in this state often need fluids from a vet, sometimes through an IV. Offering water to a dog who will not drink is not a fix, so do not delay the call.
Feeding after it settles
When the vomiting has stopped and stools are firming up, many vets suggest small portions of a bland diet. The AKC describes boiled chicken and rice as an at-home approach for mild diarrhea. VCA describes a gradual return to normal food, noting that for diarrhea a transition back to the regular diet over seven to ten days is typical. Our guide on what to give a dog for an upset stomach walks through the bland diet step by step. If you are trying to figure out what a particular color means, our post on yellow bile is a good place to start.
Why gut bacteria matter after a stomach bug
Your dog's intestines are home to trillions of bacteria that help with digestion. A bout of diarrhea can change that balance. Researchers are actively studying how these bacteria change and how to support them in dogs. That is a science area still developing, so we will not overstate it, but it is the reason owners often ask about gut health after a rough few days. If you want the background, our article on probiotics, vomiting, and dogs and cats explains how gut bacteria fit in.
Where a daily probiotic may fit
A probiotic is not a treatment for vomiting or diarrhea and does not replace a vet visit. Still, after your vet has cleared your dog, some owners look for ways to support everyday digestive health. VCA says several probiotic products may help dogs with diarrhea, and it also advises asking your vet first, because the quality and effectiveness of these products are not always known. Published research has looked at probiotics in dogs with acute diarrhea, and a canine-specific probiotic product has been studied in dogs with acute or intermittent diarrhea. Results depend on the product and the dog, so talk to your vet about whether it makes sense for yours.
Probonix for Dogs is a liquid probiotic with 8 strains that goes right on your dog's food, 6 drops a day for small dogs and 8 drops for medium and large dogs. It can help maintain healthy digestion as part of a routine your vet is comfortable with. It is a dietary supplement, not a drug, and is not intended to diagnose, treat, cure, or prevent any disease.
Frequently asked questions
How long does vomiting and diarrhea last in dogs?
Mild cases in healthy adult dogs often ease within a day or two. VCA says to see a vet if loose stools last more than two days or vomiting continues for more than one to two days, and sooner for puppies, seniors, or any dog who seems unwell.
Can I give my dog Imodium?
Do not give it unless your vet tells you to. Human anti-diarrheal products can be unsafe for some dogs and may hide a problem that needs treatment. Ask your vet what is safe for your dog, and never guess at a dose.
Is it parvo?
It could be, especially in an unvaccinated or partly vaccinated puppy. VCA notes diarrhea is one of the first signs of parvovirus, a life-threatening infection. Call your vet at once for a puppy with vomiting and diarrhea, and tell the clinic about vaccination status.
How do I know if my dog is dehydrated?
Look for dry or sticky gums, thick saliva, low energy, and a lost appetite. If you see these signs, or your dog will not drink, call your vet right away.
Can probiotics help after diarrhea?
A probiotic may support everyday digestive health once your vet has ruled out serious problems, but it is not a treatment. Ask your vet before starting one, especially if symptoms are ongoing.
Want to support your dog's gut after a rough few days?
Probonix for Dogs is a liquid, 8-strain probiotic, $37.97 for a 30-day supply, with 25% off on Subscribe & Save and a 30-day money-back guarantee.
Sources
- VCA Animal Hospitals: Diarrhea in Dogs
- VCA Animal Hospitals: Vomiting in Dogs
- VCA Animal Hospitals: Gastroenteritis in Dogs
- Merck Veterinary Manual: Vomiting in Dogs
- American Kennel Club: Dog Diarrhea
- American Kennel Club: Dog Vomiting
- ASPCA Animal Poison Control Center
- PMC: probiotic trial in dogs with acute diarrhea
- PubMed: canine probiotic product in dogs with diarrhea
This article is for general information and is not a substitute for professional veterinary advice. If your dog is vomiting or has diarrhea and you are worried, call your veterinarian. These statements have not been evaluated by the FDA. Probonix is a supplement, not a drug, and is not intended to diagnose, treat, cure, or prevent any disease.