Famotidine is a type of histamine-2 (H2) receptor antagonist which works by preventing the production of stomach acids. It is a very common non-prescription anti-ulcer medication in humans. Famotidine is currently not approved by the FDA for use in dogs or other animals. However, this has not prevented veterinarians and pet owners alike from using it to help treat dogs that may have a variety of gastrointestinal problems that are responsive to famotidine therapy. As such, its use should always be done in consultation with your veterinarian.

famotidine for dogs


Famotidine is generally used in the management of the following canine health conditions:

  • Gastric and duodenal ulcers

Ulcerations in either the stomach or the duodenum are typically brought about by the corrosive nature of stomach acids and intestinal enzymes. Food in the stomach and duodenum helps provide a protective layer so that the gastric and duodenal fluids do not erode the surface lining of these structures. However, if food is not present or if there is an abnormal secretion of gastric acids and intestinal enzymes, these acids can easily erode the surface tissues leading to the formation of ulcers.

  • Acid reflux

This should not be confused with heartburn or Gastroesophageal reflux disease, although they are characterized by the same mechanism. In acid reflux there is a backward flow of gastric acids from the stomach and into the dog’s esophagus. This is mostly related to increased pressures in the stomach or the intestines which push the acids backwards.

  • Gastroesophageal reflux disease

In Gastroesophageal reflux disease or GERD, the main pathology is in the frequent regurgitation of stomach acids. One of the most common symptoms of GERD is heartburn. GERD is considered as a more severe form of acid reflux and is often accompanied by a few other symptoms not seen in simple acid reflux.

  • Esophagitis

This is inflammation of the esophagus especially related to acid reflux. The tissues of the esophagus are not designed to accommodate the highly acidic nature of stomach acids, causing inflammation.

  • Gastritis

This refers to the inflammation of the inner layer of the stomach. It is usually a sign of a slowly-developing ulcer. There’s no ulcer yet but over time gastritis will develop into gastric ulcers.

Benefits of Famotidine

The benefits of famotidine for dogs are closely tied to how the drug works and its various clinical indications. Generally, when you give famotidine to your dog, you can expect the following benefits.

  • Alleviates pain and other symptoms associated with gastric or duodenal ulcers, GERD, acid reflux, esophagitis, or gastritis.
  • Provides optimum comfort related to the reduction in pain experience.
  • Aids in the treatment of painful gastric or duodenal ulcers.
  • Prevents the development of gastric ulcers related to the use of NSAIDs or other canine medications that are known to cause gastric irritation.

How Famotidine Works

Being an H2 receptor antagonist, famotidine works by attaching itself to histamine type-2 receptors found in the parietal cells of the dog’s stomach. One of the functions of parietal cells is the production of gastric acids, particularly hydrochloric acid or HCl. Because the functions of these cells are dampened, there is a resulting reduction in the production of hydrochloric acids. This is what gives famotidine its remarkable antacid effects. In fact, famotidine has been shown to be 9 times more effective than the 2nd generation of H2-antagonist, ranitidine, and up to 32 times more effective than the first generation of H2-antagonist, cimetidine.

Potential Side Effects

Famotidine for dogs is generally safe with the exception of dogs that may be allergic to some of the components of the drug. Some of the side effects that are known to occur, albeit rarely, include the following:

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

As always if your dog develops an allergic reaction as evidenced by wheezing, difficulty breathing, rashes, or swelling of the tongue, face, or lips, then it is important to bring it to your vet at once.

Things You Should Know about Famotidine

Famotidine is often given to dogs that have ulcers or heartburn. However, it is not approved by the FDA to be used on any pet and as such its use should be with the guidance of your veterinarian.

What You Should Tell Your Vet Before he Prescribes Famotidine

Since famotidine is not actually approved for veterinary use by the FDA, you should always make it a point to talk with your vet about it. If your dog has a kidney, heart, or liver problem, then your vet should know about it. The same is true if your pet is pregnant as famotidine may have an effect on weight gain.

How to Give Famotidine to Your Dog

The current recommended dose of famotidine for dogs is between 0.25 mg and 0.50 mg for every pound of bodyweight. The computed dose should be given twice daily preferably 12 hours apart. Famotidine for dogs comes in 10-mg tablets although there are also 20-mg tablet formulations. It is important to seek the guidance of your vet as he will tell you for how long your pet will be on famotidine. Make sure to adhere to these recommendations.

What to Do If You Miss a Dose

Missing a dose simply means giving the missed dose immediately. However, if it is already almost time for your dog’s succeeding dose, then forget the missed dose.

What to Do in Case of Famotidine Overdose

Famotidine overdose is exceptionally rare, unless you gave the whole bottle of famotidine to your pet. In such cases your dog may develop redness in its mouth or ears, vomiting, very fast heart rate, restlessness, and even collapse. Bring your dog to the vet immediately.

famotidine for dog

Some Drug Interactions

Metoclopramide, ketoconazole, sucralfate, digoxin, and other types of antacids may react with famotidine. There is also a possibility that other drugs as well as nutraceuticals and supplements might interact with famotidine in a negative way. Make sure to inform your vet about the substances your dog is taking prior to the administration of famotidine.

Famotidine for dogs is a safe and effective drug for managing, treating, and preventing gastric and duodenal ulcers as well as related diseases. Because it is not duly-approved by the FDA, it should be used with caution and with the guidance of your vet.


Olivia Williams
Olivia is our head of content for MyPetNeedsThat.com, mum of one and a true animal lover. With 12 different types of animal in her family, it's never a dull moment. When she isn't walking the dogs, feeding the cats or playing with her pet Parrot Charlie, you will find her product researching and keeping the site freshly updated with the latest products for your pets!


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