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oxy-TOH-sin - Pronunciation guide

Brand Names

  • OxoJect
  • Oxytocin Injection


Rx symbolOxytocin is a hormone secreted by the pituitary gland and stored in the brain.  Oxytocin is released during labor, causing contractions of the uterus and milk letdown.  It may also be used after foaling to help stabilize the mare's uterus and prevent complications.


Drugs containing oxytocin may be given to induce labor or to increase contractions during a difficult phase of labor. After foaling, it may be used to stimulate contractions to expel the placenta, control bleeding, and contract the uterus.  Some veterinarians use it after breeding to evacuate any excess fluid from the mare's uterus.

Dosage and Administration

Prescription medicationCyproheptadine
Method Dosage
(click row for calculator)
Concentration Period Duration
To induce labor
Intramuscular or Intravenous injection1 0.5-10 or 40-120 IU2 20 IU/ml Treatment NA
To increase milk letdown
Intramuscular or Intravenous injection 20 IU 20 IU/ml May be repeated every 20 to 30 minutes NA


  • 1Mix with 1 liter sterile normal saline for slow IV.
  • 2Low dosage and high dosage regimens.
  • 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

Sweating, cramping, and colicky discomfort are the most common side effects with use of oxytocin.


Oxytocin should not be used if the fetus is in an abnormal position or too large to pass through the birth canal.

Artificial induction of labor has significant risks of complication to both the mare and the foal and should not be used without carefully weighing all risks and benefits.

Oxytocin is FDA approved for use with horses and is a prescription drug restricted to use by or on the lawful written or oral order of a licensed veterinarian.

Oxytocin is not commonly used in competition horses.  It is important to check with the individual regulatory group.


No drug interaction are noted in the literature.


Overdose may cause excessive uterine contractions and possible rupture.


Oxytocin Bio InjectionOxytocin Bio Injection

Oxytocin InjectionOxytocin Injection



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.