Famotidine for Pets

Famotidine is an acid-reducing medication sometimes prescribed for dogs and cats with stomach or esophageal irritation, reflux, or ulcers. It is commonly used in veterinary medicine, but pet owners should use it only under a veterinarian's guidance.

Quick Facts About Famotidine

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Drug class

H2-receptor antagonist (acid reducer).

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Common brand names

Pepcid®, Apo-Famotidine®.

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Common forms

Tablet, oral liquid or compounded suspension, and injection.

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Species used for

Dogs and cats; use in pets is typically off-label and should follow a veterinarian's instructions.

What Famotidine Is Used For

Famotidine reduces stomach acid production by blocking H2 receptors in the stomach. Veterinarians may prescribe it for problems such as gastrointestinal ulcers, esophagitis, acid reflux, and some forms of gastritis, including irritation associated with kidney disease, stress, or certain medical conditions. In current veterinary practice, acid suppression is chosen based on the pet's diagnosis, and for some ulcer conditions proton pump inhibitors may provide stronger acid suppression than H2 blockers like famotidine. Your veterinarian will decide whether famotidine is the right option for your pet.

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Side Effects to Watch For

Many pets tolerate famotidine well, but side effects can happen.

  • Common side effects can include vomiting, diarrhea, decreased appetite, dry mouth, dry skin, or lethargy.
  • Pets given injectable famotidine may develop a low heart rate.
  • Rare reactions may include low white blood cell count or signs of drug sensitivity.
  • Contact your vet promptly if side effects are persistent, worsening, or your pet seems weak, collapses, has trouble breathing, or develops facial swelling.
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Dosing & Administration

Always follow your vet's instructions. Famotidine is usually given by mouth, and many veterinarians recommend giving it on an empty stomach before a meal. If your pet vomits when it is given without food, ask your veterinarian whether giving it with a small amount of food is appropriate. Do not change the dose, frequency, or duration unless your veterinarian tells you to. Tell your vet about all other medications, supplements, and health conditions, especially kidney, liver, or heart disease, pregnancy, or nursing. Store the medication exactly as labeled, and use extra caution with liquid or compounded forms because storage instructions can vary.

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When to Call a Vet

Emergency

Go to the ER now

  • Trouble breathing, facial swelling, hives, or collapse after a dose.
  • Suspected overdose, including accidental ingestion of a full bottle or multiple tablets.
  • Severe weakness, fainting, or other sudden concerning signs.
Urgent

See a vet within 24 hours

  • Repeated vomiting, ongoing diarrhea, refusal to eat, or worsening stomach upset after starting the medication.
  • Your pet has kidney, liver, or heart disease and seems more tired or unwell than expected.
  • You are not sure whether famotidine is safe with your pet's other medications.
Monitor

Watch at home, call if it worsens

  • Mild stomach upset that resolves quickly.
  • A single missed dose with no symptoms—follow your vet's instructions and do not double up unless directed.
  • Questions about giving the medication with food or how to store a liquid form.

Famotidine FAQs

Can I give my dog human famotidine?
Only if your veterinarian tells you to. Human famotidine products may have different strengths or inactive ingredients, and not every upset stomach should be treated at home. Call your vet before giving any over-the-counter medication.
What happens if I miss a dose?
Give the missed dose when you remember, unless it is almost time for the next one. If it is close to the next dose, skip the missed dose and return to the regular schedule. Do not give two doses at once unless your veterinarian specifically instructs you to.
Can my cat take famotidine?
Yes, veterinarians do prescribe famotidine for some cats, but it should only be used under veterinary guidance. Cats may need individualized treatment based on the cause of their symptoms and any other medical problems.
Is famotidine the same as Pepcid®?
Pepcid® is a brand name for famotidine. However, that does not mean every human product is automatically appropriate for pets. Always confirm the exact product with your veterinarian.
Are there medicines that can interact with famotidine?
Yes. Famotidine can affect how some other medications are absorbed or used. VCA lists cautions with drugs including certain azole antifungals, cefpodoxime, cefuroxime, cyclosporine, and iron salts. Make sure your veterinarian knows everything your pet takes, including supplements.

Disclaimer: The information provided in this article is for educational purposes only and does not constitute veterinary medical advice. Reading this content does not establish a veterinarian-client-patient relationship. Every pet is different — always consult a licensed veterinarian before making decisions about your pet's health, diet, or care. If you'd like personalized guidance, you can talk to one of our vets. If your pet is experiencing a medical emergency, contact your local emergency animal hospital immediately.

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