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Medication Guide • Reviewed by Dr. Tiffany Delacruz, DVM

Famotidine (Pepcid) for Dogs

Famotidine reduces stomach acid in dogs and is used to treat or prevent stomach ulcers, acid reflux, and stomach inflammation.

Generic: famotidine Class: H2 receptor antagonist (acid reducer) Over-the-counter (vet guidance recommended)
Important: This page is an educational reference. Never start, stop, or change your pet's medication without veterinary guidance. Specific dosing depends on your pet's weight, condition, and other medications. To get a personalized prescription or refill, talk to a licensed RexVet veterinarian.

What Famotidine (Pepcid) is used for in dogs

  • Gastric ulcers
  • Acid reflux
  • Stomach inflammation
  • Pre-treatment for NSAID-sensitive dogs

How it works

Famotidine blocks H2 histamine receptors in the stomach lining, reducing acid production by about 70-80%.

Available formulations

10 mg tablet (OTC)

20 mg tablet

Liquid

Side effects to know

Common side effects

  • Generally well tolerated
  • Mild constipation

These usually resolve on their own. If they persist past the first few doses, ask your vet.

Call your vet immediately if you see

  • Rare — severe lethargy

Drug interactions

  • Minor — separates from antacids by 2 hours

When not to use

  • Severe kidney disease (dose adjustment)

Monitoring during treatment

Generally low-risk. If used long-term with NSAIDs, periodic bloodwork is wise.

Need a Famotidine (Pepcid) refill?

RexVet is the first 501(c)(3) non-profit online vet service in the U.S. Talk to a licensed veterinarian by video, get your dogs's Famotidine (Pepcid) prescription, and have it shipped through RexVetRx — all for $64.99 per visit.

Book a vet visit — $64.99

Famotidine (Pepcid) for Dogs

Frequently asked questions

Can I give my dog Pepcid?

Yes — famotidine is one of the few human medications routinely given to dogs at vet-determined doses. Confirm with a vet before starting.

How much Pepcid can I give my dog?

General guidance is 0.25-0.5 mg per pound, given once or twice daily. Always confirm with your vet first.

When is famotidine needed?

Most commonly: dogs on NSAIDs that show GI upset, dogs with vomiting from suspected acid reflux, or as part of treatment for stomach ulcers.

Can RexVet recommend famotidine?

Yes — a RexVet video visit can confirm whether famotidine is appropriate, recommend the right dose, and rule out anything that needs more aggressive treatment.

Famotidine vs omeprazole?

Famotidine reduces acid 70-80%. Omeprazole (Prilosec) reduces it 90%+. For severe cases, omeprazole is often preferred; for mild cases, famotidine is sufficient and lower-cost.

Medical review by Dr. Tiffany Delacruz, DVM

Chief Executive Officer & Lead Veterinarian, RexVet. Licensed in Florida, New York, and Virginia.

Last fact-checked: 2026-05-19

Sources

This page is an educational reference and does not replace veterinary advice. Always consult a licensed veterinarian before starting, changing, or stopping medication for your pet.