Famotidine (Pepcid) Dosage for Dogs — Chart & Calculator by Weight
Dose ranges on this page are published veterinary references for education only. Your veterinarian's prescribed dose always wins. When in doubt, call your vet first.
Famotidine — sold as Pepcid — is an H2 blocker that reduces stomach acid. Veterinarians use it in dogs for acid reflux, gastritis, stomach ulcers, and vomiting. The Merck Veterinary Manual and Plumb's reference a standard range of 0.5–1 mg per kg of body weight, given every 12–24 hours.
Use the calculator below for your dog's weight, or scroll to the full dosage chart. Only plain famotidine should be used — some Pepcid combination products contain other active ingredients that are not safe for dogs.
Dose calculator
Dosage chart by weight
| Dog weight | Dose range per dose |
|---|---|
| 5 lb | 1.1–2.3 mg |
| 10 lb | 2.3–4.5 mg |
| 15 lb | 3.4–6.8 mg |
| 20 lb | 4.5–9.1 mg |
| 30 lb | 6.8–13.5 mg |
| 40 lb | 9.1–18 mg |
| 50 lb | 11.5–22.5 mg |
| 60 lb | 13.5–27 mg |
| 80 lb | 18–36.5 mg |
| 100 lb | 22.5–45.5 mg |
Chart uses the same conservative range as the calculator (0.5–1 mg per kg of body weight). Always confirm with your veterinarian.
Common formulations
- Tablets — 10 mg tablets
Standard Pepcid AC strength; 20 mg maximum-strength tablets also exist
Use the calculator above to convert any of these sizes into an amount for your pet's weight.
How often to give it
Every 12–24 hours. 0.5–1 mg per kg of body weight.
Common veterinary uses
- Acid reflux and heartburn
- Gastritis
- Stomach ulcers
- Frequent vomiting (vet-directed)
- Stomach protection during certain drug therapies (vet-directed)
Safety warnings
Possible side effects
- Usually well tolerated
- Rare: decreased appetite, mild vomiting or diarrhea
- Use PLAIN famotidine only. Avoid Pepcid Complete and other combo products with extra active ingredients — they are not formulated for dogs.
- Famotidine works best given before the first meal of the day, but can be given with food.
Do not use (or ask your vet first)
- Dogs allergic to famotidine or to cimetidine (another H2 blocker)
- Tell your vet about all other medications — famotidine can change how some drugs (certain antifungals, antibiotics, iron supplements) are absorbed
When to see a veterinarian
- Vomiting blood or material that looks like coffee grounds
- Black, tarry stools
- Vomiting or diarrhea lasting more than 24 hours
- Abdominal pain, bloating, or collapse
- No improvement within a few days of vet-directed use
Frequently asked questions
How much Pepcid can I give my dog?
The standard published range is 0.5–1 mg/kg every 12–24 hours — for example, a 20 kg (44 lb) dog would be roughly 10–20 mg per dose, which is one to two 10 mg tablets. Confirm with your vet.
Can I give my dog Pepcid every day?
Veterinarians do prescribe it for ongoing use in some conditions, with monitoring. Long-term daily use should be vet-directed — don't start a daily regimen on your own.
How fast does famotidine work in dogs?
Blood levels peak about 2 hours after an oral dose, and the effect can last up to 24 hours.
Is Pepcid AC or Pepcid Complete safe for dogs?
Stick to plain famotidine (regular Pepcid AC tablets contain only famotidine, but always check the label). Avoid Pepcid Complete and any combo product with additional active ingredients.
Should famotidine be given with food?
It works best given before the first meal of the day, but it can also be given with food. Follow your veterinarian's instructions.
Sources
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Dose ranges on this page are published veterinary references for education only. Your veterinarian's prescribed dose always wins. When in doubt, call your vet first.