Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Vets do use stomach-acid reducers in dogs and cats, mainly famotidine (Pepcid) and omeprazole, plus the stomach protectant sucralfate. But they only help for specific problems such as ulcers, acid reflux, or esophagus inflammation, and the right drug, dose, and duration depend on your pet. Don’t give human antacids without your vet’s advice: some products contain ingredients that are harmful to pets, and vomiting or stomach pain can be a sign of something that antacids won’t fix.
Types of acid medications vets use
- Proton pump inhibitors (PPIs) such as omeprazole and pantoprazole. Specialist guidance from the American College of Veterinary Internal Medicine (ACVIM) found these are the most effective acid reducers in dogs and cats.
- H2 blockers such as famotidine. Milder and shorter-acting, and studies show they lose effect with repeated daily use. (Ranitidine was withdrawn from the US market in 2020.)
- Sucralfate: not an antacid, but a coating that protects ulcers. It can block absorption of other drugs, so timing matters.
- Classic antacids (calcium carbonate, aluminum or magnesium hydroxide): these only neutralize acid briefly and are rarely the best choice for stomach problems.
When antacids help, and when they don’t
According to the ACVIM consensus, acid reducers are worthwhile for:
- Stomach or intestinal ulcers, including those caused by NSAIDs or steroids
- Acid reflux and inflammation of the esophagus (esophagitis)
- Some conditions that cause excess stomach acid, such as certain tumors
They are not recommended routinely for mild vomiting or diarrhea, for kidney disease without ulcers, or “just in case” alongside every NSAID, because they don’t clearly help in those cases and can have side effects.
Side effects and precautions
- PPIs work best given twice daily before a meal, as your vet directs.
- After more than a few weeks on a PPI, stopping suddenly can cause rebound acid. Your vet may taper the dose.
- Long-term acid suppression may change gut bacteria and affect absorption of some nutrients and drugs.
- Pets with kidney or liver disease may need dose adjustments.
Human antacid products to be careful with
- “Complete” or combination products: Pepcid Complete, for example, also contains calcium carbonate and magnesium hydroxide. Plain famotidine is what vets usually mean.
- Xylitol: some chewable and “sugar-free” antacids contain xylitol, which is highly toxic to dogs.
- Tums and other calcium antacids: an occasional tablet is unlikely to harm a healthy dog, but it does little, and extra calcium is a problem for pets with kidney disease, bladder stones, or high calcium.
- Pepto-Bismol (bismuth subsalicylate): contains a salicylate related to aspirin. It’s unsafe for cats and should only be used in dogs if your vet says so. It can also turn stool black, which hides signs of bleeding.
- Alka-Seltzer: contains aspirin. Don’t give it to pets.
When to see a vet instead
Call your vet promptly if your pet has:
- Repeated vomiting, or vomit with blood or “coffee ground” material
- Black, tarry stool
- A swollen or painful belly, or retching without bringing anything up (in dogs, this can be bloat, an emergency)
- Stopped eating, or lethargy
- Stomach upset after eating something toxic, or while on an NSAID pain reliever
Gentle home care vets commonly recommend
- Small, frequent meals of a bland or prescription gastrointestinal diet, if your vet agrees.
- For dogs with reflux, avoid a big meal right before bedtime.
- Avoid fatty table scraps and sudden diet changes.
- Keep NSAIDs, steroids, and human medications stored out of reach.
For more on reflux specifically, see our guide to acid reflux in dogs.
Frequently asked questions
Can I give my dog Pepcid?
Famotidine is commonly prescribed for dogs, but ask your vet first. They’ll confirm it’s appropriate, choose the right strength, and make sure your dog’s symptoms don’t need other treatment.
Can cats take antacids?
Cats are sometimes prescribed famotidine or omeprazole. Never give a cat a human antacid on your own, and never give Pepto-Bismol or aspirin-containing products.
How fast do antacids work in pets?
Famotidine starts working within hours. PPIs like omeprazole take a few days of regular dosing to reach full effect.
Sources
- Marks SL, et al. ACVIM consensus statement: Support for rational administration of gastrointestinal protectants to dogs and cats. J Vet Intern Med. 2018
- Merck Veterinary Manual: Drugs used to control gastric acidity
- ASPCA Animal Poison Control Center: xylitol and human medications
- US FDA: Request to remove all ranitidine products from the market (2020)
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.