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H2 receptor antagonist · For Cats

How much Famotidine (Pepcid) can I give my cat?

Standard Famotidine dose for cats is 0.5 mg per kg (0.23 mg per lb), given every 12-24 hours. Use the calculator below for your cat's exact weight, or jump to the weight-by-weight chart.

Onset
30-60 minutes
Duration
12-24 hours
Class
H2 receptor antagonist

Calculator estimate from Plumb’s Veterinary Drug Handbook. Independent DVM review is being added page by page — see our methodology .

This information is for educational purposes only. Always consult your veterinarian before giving medication to your pet. Do not use this calculator for emergencies, overdoses, pregnancy, very young animals, very old animals, pets with liver/kidney disease, or pets taking multiple medications.

Dosage data is sourced from Plumb's Veterinary Drug Handbook and cross-referenced with Merck Veterinary Manual and DailyMed where applicable. Independent DVM review is being added page by page. See our methodology.

Famotidine (often known by brand names such as Pepcid) is an H2 receptor antagonist commonly used in veterinary medicine for stomach acid reduction, gastritis, acid reflux, and nausea. Understanding the correct dosage, administration, and potential side effects of Famotidine is critical for your cat’s safety and well-being.

A typical Famotidine dose for cats is around 0.5 mg/kg every 12-24 hours, within a usual range of 0.25-1 mg/kg. Available forms include tablet and injectable.

Calculator Warning: Use this only as an educational estimate. Your veterinarian may prescribe a different dose based on your pet’s condition, age, weight, other medications, and medical history.

Famotidine Dosage Calculator for Cats

Enter your cat’s weight below to estimate the Famotidine dose from the 0.5 mg/kg guideline. Your veterinarian may adjust it for your cat’s age, condition, and other medications, so treat the result as an educational starting point, not a prescription.

Dosage Calculator · 01

Enter your cat's weight

Quick Dosage Chart

Typical Famotidine amounts for common cat weights, for quick reference:

Dosage Chart · 02

Pepcid dosage for cats by weight

Scroll sideways to see full table

Weight Low Dose Standard Max Safe Frequency
3 lbs (1.4 kg) 0.5mg 0.5mg 1.5mg every 12-24 hours
4 lbs (1.8 kg) 0.5mg 1mg 2mg every 12-24 hours
5 lbs (2.3 kg) 0.5mg 1mg 2.5mg every 12-24 hours
6 lbs (2.7 kg) 0.5mg 1.5mg 2.5mg every 12-24 hours
7 lbs (3.2 kg) 1mg 1.5mg 3mg every 12-24 hours
8 lbs (3.6 kg) 1mg 2mg 3.5mg every 12-24 hours
9 lbs (4.1 kg) 1mg 2mg 4mg every 12-24 hours
10 lbs (4.5 kg) 1mg 2.5mg 4.5mg every 12-24 hours
12 lbs (5.4 kg) 1.5mg 2.5mg 5.5mg every 12-24 hours
14 lbs (6.3 kg) 1.5mg 3mg 6.5mg every 12-24 hours
16 lbs (7.3 kg) 2mg 3.5mg 7.5mg (10mg tablet) every 12-24 hours
18 lbs (8.2 kg) 2mg 4mg 8mg (10mg tablet) every 12-24 hours
20 lbs (9.1 kg) 2.5mg 4.5mg 9mg (10mg tablet) every 12-24 hours
25 lbs (11.3 kg) 3mg 5.5mg 11.5mg (10mg tablet) every 12-24 hours

By Weight

Pepcid dose by cat weight

Pick your cat's weight to jump to a dedicated page with the dose, frequency, safety notes, and FAQ for that size.

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How to Give Famotidine to Your Cat

Famotidine tablets are small but may need to be cut for cat-sized doses. A pill cutter helps achieve the right dose. Give on an empty stomach 30-60 minutes before meals for best effect. You can also crush the tablet and mix with a small amount of wet food if your cat is difficult to pill.

It may interact with antacids, ketoconazole (reduced absorption), and sucralfate.

Side Effects and Safety

Common side effects include decreased appetite, drowsiness, and constipation. More serious side effects can occur, such as irregular heartbeat (rare), severe vomiting, and allergic reaction.

Cautions · 12

When Pepcid should be used with caution or avoided

Some cats should not take Pepcid, or need a different dose and closer monitoring. Tell your veterinarian about your pet's full health history and every other medication or supplement they take before giving Pepcid.

  • known hypersensitivity
  • severe kidney disease (dose adjustment needed)

Interactions · 13

Pepcid drug interactions

Pepcid can interact with other drugs. This list is not complete — always give your veterinarian a full list of your cat's medications and supplements.

antacids
ketoconazole (reduced absorption)
sucralfate

Calculator Limits · 14

When not to use this calculator

This calculator gives a general educational estimate for a healthy adult cat at a known weight. Do not rely on it in these situations — talk to your veterinarian instead:

  • In an emergency, or after accidental ingestion or a suspected overdose
  • For pregnant or nursing pets
  • For very young or very old cats
  • For pets with liver disease, kidney disease, or another chronic illness
  • For pets taking several medications at once
  • When you are not sure of your cat's current, accurate weight
  • For combination products that contain additional active ingredients

Overdose · 15

Suspected overdose: what to do

If you think your cat had too much Pepcid, or swallowed any medication by accident, act right away. Do not wait for symptoms to appear.

  • Call your veterinarian or the nearest emergency animal hospital.
  • ASPCA Animal Poison Control Center: (888) 426-4435
  • Pet Poison Helpline: (855) 764-7661

A consultation fee may apply to the poison hotlines. Have the medication packaging ready, and note how much your pet may have taken and when. Do not try to make your pet vomit unless a veterinarian tells you to.

When to Call the Vet

If your cat experiences any of the following, contact your veterinarian or an emergency clinic immediately:

Frequently Asked Questions

Frequently Asked · 07

Questions about this medication

Can I give my cat Pepcid?
Yes, Pepcid (famotidine) is commonly used for cats with stomach acid issues, nausea, and gastritis. Use the original plain formula only. Many vets recommend it for cats with chronic kidney disease who experience nausea.
How much Pepcid can I give my cat?
The typical dose for cats is 0.25-0.5 mg per kilogram of body weight, given every 12-24 hours. For an average 10 lb (4.5 kg) cat, this is approximately 2.5 mg (one quarter of a 10 mg tablet) once or twice daily.
Can Pepcid help a cat with kidney disease?
Yes, famotidine is commonly prescribed for cats with chronic kidney disease (CKD) to help manage nausea and stomach acid buildup, which is common as kidney function declines. It can help improve appetite in cats with CKD.
How long can a cat take famotidine?
Famotidine can be used short-term for acute stomach issues or long-term for chronic conditions like CKD-related nausea. Long-term use is generally well-tolerated in cats. Your vet will determine the appropriate duration.

For Dogs

Looking for Famotidine dosage for dogs?

View the Famotidine dosage chart and calculator for dogs.

Related · 08

Related medications for cats

Sources · 09

Sources & references

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Famotidine.

Read more about our methodology and how we calculate dosages.

Transparency · 11

How this page was made

Sourced from Plumb's Veterinary Drug Handbook, the reference used in US vet schools. Every dose, frequency, and tablet count on this page is generated from that data, then checked against the published references below.

Sources cited
  • Plumb's Veterinary Drug Handbook
  • Merck Veterinary Manual
Calculator formula
Doses scale linearly from a standard basis of 0.5 mg per kg (0.23 mg per lb) of body weight, given every 12-24 hours. The calculator multiplies that basis by your cat's weight and rounds to the closest available tablet size.
Last-reviewed status
Independent DVM review is being added page by page.

More on our methodology and editorial process — how we source, calculate, and review cats dosage data.

Safety · 10

More resources