Prolixin for Horses

Prolixin is a drug used in humans as an antipsychotic for the treatment of schizophrenia and bipolar disorder. When used in horses for long-term sedation, a long-acting form of the drug called Fluphenazine is used. Often drugs are used illegally in show and performance horses. To limit this practice, many equine groups require drug testing prior to competition.

  1. Description

    • Fluphenazine is a neuroleptic which affects brain function.

      Fluphenazine is a member of the large group of drugs known as neuroleptics, which primarily affect brain function. The fact that the horse is easily arousable and will respond when stimulated makes neuroleptics different from other sedatives. Neuroleptics suppress spontaneous motor activity and aggressive behavior without inducing the inability to coordinate muscle movement.

    Uses

    • It is used to help reduce stress during prolonged stall rest, separation from a buddy and foal rejection by a mare, as well as modifying initial aggression when introducing new horses and alleviating chronic pain.

    Side Effects

    • Side effects seen in horses have included unpredictable, severe and life-threatening behavior consistent with Parkinsonism. In a study completed at the University of Guelph's Ontario Veterinary College, researchers examined abnormal behavior of racehorses that were medicated with fluphenazine decanoate. Behaviors included "restlessness, agitation, profuse sweating...muscle disorder characterized by overreaching, aimless circling, intense pawing...and rhythmic swinging of the head and neck alternating with episodes of severe stupor."

    Treatment

    • Administering diphenhydramine hydrochloride--an antihistamine--resolves the clinical signs caused by fluphenazine. It is not always effective, and according to University of Guelph's Ontario Veterinary College, some horses have had to be euthanized due to "severe neurological signs, respiratory failure, and acute renal failure."

    Banned

    • According to the AgriLife Extension at Texas A&M, fluphenazine use in horses is a violation of the FDA Legal Drug Use Act, banned by the United States Equestrian Federation. Moreover, it is not approved by the U.S. government's Food and Drug Administration (FDA).