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The FDA has not approved this medication for veterinary use, but veterinarians may still prescribe famotidine for dogs. 


The usual dosage of famotidine that is given to dogs is 0.50 mg to 1 mg per kg of body weight given twice daily. 

Side Effects

Side effects in dogs are rare, which is why veterinarians often prescribe famotidine over other medications that treat gastrointestinal issues. When side effects in dogs present themselves, they may include:

  • Loss of appetite
  • Headache
  • Constipation
  • Diarrhea
  • Drowsiness


Famotidine may not be safe for dogs with kidney or liver problems, stomach cancer, and sensitivity to similar medications. Moreover, because the drug can pass through breast milk, it is not recommended for dogs that are pregnant or nursing.


Should famotidine for dogs be given with food?

No, famotidine should be given on an empty stomach before the first meal of the day.

Does famotidine help with diarrhea in dogs?

No, famotidine can cause diarrhea.

Is Pepcid or omeprazole better for dogs?

Studies in healthy dogs and cats have shown that omeprazole (Prilosec OTC, OmePPi, Zegerid OTC) is more effective than Pepcid and is often recommended for the treatment of stomach and intestinal ulcers.

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