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Ranitidine for Pets: Ulcer Treatment, Gastritis & Acid Reduction

Published on September 10, 2024
Updated on November 5, 2025
Reviewed by Petco's Veterinarian Team

Ranitidine is a histamine blocker used for ulcer treatment and prevention. Ranitidine is not longer available in the U.S. Ranitidine was withdrawn from the market due to the presence of NDMA (N-nitrosodimethylamine), a known carcinogen and that may also be hepatoxic. NDMA in ranitidine is likely due to manufacturing and levels increase with storage/shelf life based on over time and based on temperature in which ranitinidine products stored.

Summary

Used For:

Stomach ulceration, esophageal ulceration, increasing food transit through the GI tract

Brands:

Zantac

Species:

Dogs, cats, horses, cattle

Other names:

Drug type:

Gastrointestinal

Prescription required:

No

Pregnancy and lactation:

Safe to use in pregnant and lactating animals.

Side effects:

Vomiting, diarrhea, irregular heartbeat, muscle tremors, rapid breathing

General description

Ranitidine is in a class of drugs called Histamine type-2 (H2) receptor antagonists. It is used to decrease the amount of stomach acid released. This aids in the treatment of ulcers that are present and helps prevent ulcer formation in dogs and cats. It is also used in the treatment of gastritis (inflammation of the stomach), esophagitis (inflammation of the esophagus), and gastric or esophageal reflux. It may also stimulate movement of food through the stomach and intestine. However, proton pump inhibitors (PPI), such as omeprazole (Prilosec), may be more effects. Side effects are uncommon with Rantidine.

Uses

Ranitidine is used for GI ulcers, gastritis and/or esophagitis, though proton-pump inhibitors (eg, omeprazole) may be superior

How it works

Ranitine, like famotidine (Pepcid), is a H2 receptor antagonist. This type of medicaiton inhibits baseline and meal-stimulated acid secretion making the environment in the stomach more alkaline. Ranitidine in particular also have promotility effects, which means is increases GI movement of food.

Dosage

Dogs: 2 milligrams per kilogram of body weight given orally every 8 - 12 hours.

Cats: 3.5 milligrams per kilogram of body weight given orally twice daily.

Ferrets: 24 milligrams per kilogram of body weight given orally every 8 - 12 hours.

Horses: 6.6 - 10 milligrams per kilogram of body weight given orally every 8 hours.

Rabbits: 2 - 5 milligrams per kilogram of body weight given orally twice daily.

Forms

75, 150 and 300 milligram tablets available; 25 milligram/milliliter injectable form.

Storage information & handling

Tablets: Keep dry and away from direct sunlight.

Injectable: Store in a cool place away from direct sunlight.

What results can I expect?

Lack of appetite and gastric reflux should decrease when animals begin taking this medication. It can take several days to see the full effects. However, Clinical studies on the effect of ranitidine on gastric disorders in dogs and cats are lacking.

Missed Dosage

This medication is very safe, if a dose is missed another dose can be given immediately.

Overdose / acute toxicity

Overdose is rare.

Side effects

May include:

  • Vomiting

Adverse effects are uncommon in animals with oral administration

Contraindications

*Do not use in patients with a known hypersensitivity.

Drug interactions

  • ACETAMINOPHEN
  • ANTACIDS give at separate times (2 hours apart) if used concurrently.
  • AZOLE ANTIFUNGALS (eg, ketoconazole, itraconazole, fluconazole): administer the azole 1 hour prior to ranitidine.
  • CEFPODOXIME, CEFUROXIME: Ranitidine may decrease the absorption of these cephalosporins; giving with food may alleviate this effect.
  • IRON supplments; administer iron at least 1 hour prior to ranitidine.
  • PROPANTHELINE: Delays the absorption but increases the peak serum level of ranitidine; relative bioavailability of ranitidine may be increased by 23% when propantheline is administered concomitantly with ranitidine.
  • VITAMIN B-12: Long-term ranitidine use may reduce oral absorption of B12.

Precaution

None

Laboratory considerations

  • Ranitidine may cause a false-positive urine protein reading when using Multistix®.
  • Gastric acid secretion testing: discontinue at least 24 hours before performing this test.
  • Intradermal allergy testing: discontinue at least 24 hours before performing this test.

Sources

  • Saunders Handbook of Veterinary Drugs
  • Plumb’s Veterinary Formulary
  • Marks, S. L., Kook, P. H., Papich, M. G., Tolbert, M. K., & Willard, M. D. (2018). ACVIM consensus statement: Support for rational administration of gastrointestinal protectants to dogs and cats. Journal of Veterinary Internal Medicine, 32(6), 1823–1840. https://doi.org/10.1111/jvim.15337
  • Manufacturer information: Sanofi - Zantac

Disclaimer
The information contained on this page is for educational purposes only. This medication should only be given under the advice of a veterinarian who has examined your pet under the laws applicable to your state of residence.

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