Fluphenazine Reactions in Horses

March 12, 2007 (published) | September 17, 2012 (revised)

It seems many folks in the performance and show horse businesses are always looking for some way of getting a jump on the competition and some of the methods used are not always legal or ethical. Many show and performance horse people commonly use human drugs for various reasons to affect the animal's performance in a positive manner depending on their goal at the show. This use of these drugs goes unnoticed because many smaller shows and rodeos do not perform drug testing.

One commonly used drug in horses is fluphenazine. It is a human drug that is a highly potent antipsychotic that is used in people with schizophrenia and other psychotic illnesses. Now if you are not in the show horse world, you may be thinking why in the world would someone give a human antipsychotic drug to a horse? Well, the drug is used as a long-acting sedative and to decrease anxiety and modify behavior. It is commonly used in show horses that are nervous when showing or may be too excitable to perform correctly in a performance event.

However, the side effects of this drug can be extremely dangerous for the horses and people around them. After intramuscular injection of a long-lasting product, side effects include severe depression and sleepiness as well as frantic, compulsive movements. Affected horses may have muscle trembling, agitation, restlessness, and may compulsively circle the stall. They may throw their heads, strike and rear, and they may develop seizures and become recumbent. Obviously, the horse as well as humans in the vicinity can be injured when an animal of this size is out of control. Because of these side effects, fluphenazine should not be used in horses. The drug is considered by the United States Equestrian Federation as a forbidden substance.

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