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ran-IT-ih-deen - Pronunciation guide

Brand Names

  • Zantac®


Rx symbolRanitidine is an ulcer medication effective in both people and horses. As an H-2 blocker, it reduces acid production.


Ranitidine is used to treat gastro-duodenal ulcers in horses. The first step in treatment of ulcers in horses is the removal of stressful conditions and discontinuation of any anti-inflammatory medications. Veterinarians often recommend a combination of medications and a treatment period of at least three to four weeks.

Dosage and Administration

Prescription medicationRanitidine
Method Dosage
(click row for calculator)
Concentration Period Duration
Oral 6.6 mg/kg 300 mg/tablet 3 times daily NA
Intravenous injection 1-2 mg/kg 25 mg/ml 3 times daily NA


  • Federal law restricts this drug to use by or on the order of a licensed veterinarian.
  • Extra-label use of drugs in treating animals is allowable only by licensed veterinarians within the context of a valid veterinarian-client-patient relationship, and does not include drug use in treating animals by the layman (except under the supervision of a licensed veterinarian).
  • The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your equine appears to feel better, the entire treatment plan should be completed to prevent relapse.
  • This medication may be available in forms and concentrations not noted in the above table. Always check the label and literature provided with the medication about the form and concentration and DO NOT USE the calculator if the information differs.
  • Calculator is for educational purposes only. Follow your veterinarian's instructions regarding use of this, or any medication.

Side Effects

Ranitidine has been shown to have a wide margin of safety in laboratory animals.


Ranitidine should be used with caution or at a reduced dose in horses with liver or kidney problems.

Ranitidine is not FDA approved for use with horses, but is commonly used and considered accepted practice. U. S. federal law restricts these drugs to use by or on the lawful written or oral order of a licensed veterinarian.

Ranitidine is forbidden in any drug-free competition. It is important to check with a knowledgeable veterinarian and the individual regulatory group.


Histamine H2 receptor antagonists may affect blood clotting in animals on warfarin.

Some veterinarians recommend separating oral doses of ranitidine from antacids, metoclopramide, and sucralfate.


No information was found regarding overdose of ranitidine in horses or other animals.


Ranitidine Oral PowderRanitidine Oral Powder

Ranitidine TabletsRanitidine Tablets



About the Author

EquiMed Staff

EquiMed staff writers team up to provide articles that require periodic updates based on evolving methods of equine healthcare. Compendia articles, core healthcare topics and more are written and updated as a group effort. Our review process includes an important veterinarian review, helping to assure the content is consistent with the latest understanding from a medical professional.