Vomiting and diarrhea in dogs: treatments compared
Checked against veterinary references: October 2026
Short answer
Most mild vomiting or diarrhea in an otherwise bright adult dog settles within a day or two with small, bland meals and plenty of water. Vets treat persistent cases with anti-nausea medicines such as Cerenia or ondansetron, acid reducers, probiotics, and dewormers or antibiotics when parasites or infections are found. Repeated vomiting, blood, lethargy, a swollen belly or a sick puppy need a vet promptly.
Treatments for vomiting and diarrhea in dogs at a glance
- Veterinary anti-vomiting medicineUsed for: Vomiting and motion sicknessHow it is given: Once a dayWhat to watch for: Drooling, reduced appetiteWhere to get it: Vet
- Human anti-nausea medicineUsed for: Nausea and vomitingHow it is given: Two or three times a dayWhat to watch for: Interactions with some serotonin medicinesWhere to get it: Regular pharmacy
- Acid reducersUsed for: Gastritis, ulcers, refluxHow it is given: Before meals, once or twice a dayWhat to watch for: Use plain products onlyWhere to get it: Over the counter or regular pharmacy
- ProbioticsVeterinary products preferredUsed for: DiarrheaHow it is given: Daily with foodWhat to watch for: Quality varies; choose a veterinary productWhere to get it: Vet or pet store
- Antibiotic and antiprotozoalUsed for: Giardia, some colitis and bowel infectionsHow it is given: Twice a day with foodWhat to watch for: Wobbliness at high doses; bitter tasteWhere to get it: Regular pharmacy
- Fenbendazole (Panacur)DewormerUsed for: Worms and GiardiaHow it is given: Daily for several daysWhat to watch for: Usually well toleratedWhere to get it: Over the counter or vet
| Treatment | Used for | How it is given | What to watch for | Where to get it |
|---|---|---|---|---|
| Maropitant (Cerenia)Veterinary anti-vomiting medicine | Vomiting and motion sickness | Once a day | Drooling, reduced appetite | Vet |
| OndansetronHuman anti-nausea medicine | Nausea and vomiting | Two or three times a day | Interactions with some serotonin medicines | Regular pharmacy |
| Famotidine or omeprazoleAcid reducers | Gastritis, ulcers, reflux | Before meals, once or twice a day | Use plain products only | Over the counter or regular pharmacy |
| ProbioticsVeterinary products preferred | Diarrhea | Daily with food | Quality varies; choose a veterinary product | Vet or pet store |
| MetronidazoleAntibiotic and antiprotozoal | Giardia, some colitis and bowel infections | Twice a day with food | Wobbliness at high doses; bitter taste | Regular pharmacy |
| Fenbendazole (Panacur)Dewormer | Worms and Giardia | Daily for several days | Usually well tolerated | Over the counter or vet |
When to go to the vet now
- Retching without bringing anything up, with a swollen or tight belly, especially in large, deep-chested breeds: this can be bloat, a life-threatening emergency.
- Repeated vomiting, or being unable to keep water down.
- Blood in vomit or stool, or black, tarry stools.
- Lethargy, weakness, pale gums or signs of pain.
- A puppy, especially one not fully vaccinated, with vomiting or diarrhea, which can signal parvovirus.
- A possible toxin, medicine or swallowed object such as a toy, sock or bone.
Caring for a mild case
For an adult dog that is bright and otherwise well, your vet may suggest small, frequent meals of a bland diet such as plain cooked chicken or white fish with rice, or a veterinary gastrointestinal diet, for a few days before returning gradually to normal food. Keep fresh water available. If signs last more than a day or two, or get worse, call your vet.
Home remedies to avoid
- Loperamide (Imodium) can cause serious neurological effects in dogs with the MDR1 gene mutation, common in collies, Australian shepherds and related breeds, and can be harmful when diarrhea is caused by infection or toxins.
- Bismuth subsalicylate (Pepto-Bismol) contains a salicylate related to aspirin, which can cause stomach bleeding and interact with other medicines, and turns stools black, hiding signs of bleeding.
- Never give human anti-nausea or acid products without checking the ingredients with your vet; some liquids contain xylitol, which is poisonous to dogs.
Antibiotics are used more selectively now
Simple acute diarrhea in dogs usually resolves without antibiotics, so many vets now reserve metronidazole and other antibiotics for specific infections, such as Giardia, or for dogs with signs of more serious bowel disease. A stool test can identify parasites, which are treated with dewormers such as fenbendazole.
What about cats?
Cats also vomit and get diarrhea, but frequent vomiting is not normal for cats, even with hairballs, and a cat that stops eating for more than a day needs a vet. See medicines for cats and our comparison of Cerenia and ondansetron.
Frequently asked questions
Can I give my dog Imodium for diarrhea?
Not without your vet’s advice. Loperamide can cause serious neurological effects in dogs with the MDR1 mutation, common in herding breeds, and can make some infections worse.
Can I give my dog Pepto-Bismol?
Not without your vet’s advice. It contains a salicylate related to aspirin, which can cause stomach bleeding, and it turns stools black, which can hide bleeding.
When should I take my dog to the vet for vomiting?
Promptly if vomiting is repeated, contains blood, comes with lethargy or a swollen belly, or affects a puppy, and urgently for unproductive retching with a swollen belly. Mild, one-off vomiting in a bright adult dog can often be watched for a day.
Should I stop feeding my dog after vomiting?
Ask your vet. Many now suggest small, bland meals rather than a long fast for adult dogs, and puppies should not go long without food.