Anesthesiologist discovers new way to sedate horses

A professor at the University of Tennessee has discovered an alternative way to sedate female horses, and it’s both fast and effective.

Detomidine is a commonly-used sedative that is typically administered as a gel beneath the tongue. Though this method is pain-free, many horses resist it, spitting out the gel or stubbornly refusing the syringe altogether. Reza Seddighi, DVM, MS, PhD, Dipl. ACVAA (an associate professor specializing in anesthesiology and pain management in the University of Tennessee’s Department of Large Animal Clinical Sciences) has discovered an alternative way to sedate female horses – intravaginally.

Vaginal tissue is thin, permeable, and highly vascularized – similar to the mucosal membranes in the mouth – making it a fast and effective way of getting Detomidine into the bloodstream. Intravaginal administration also means that the sedative doesn’t have to pass through the gastrointesintal tract. Dr. Seddighi conducted a study to test this method of administration, which involved two treatment rounds. He and his team sedated and observed six mares for four hours, scoring them every 15 minutes for ataxia (incoordination), behavioral changes, appearance, muzzle-to-floor distance, and heart rate. They also had blood samples analyzed by the University of California, Davis, to see how the drug interacted in the body.

The researchers confirmed that the drug takes effect most rapidly when given intravenously. Intravaginal administration, however, worked twice as fast as sublingual (beneath the tongue) administration. The results also showed that sedation was deeper and longer-lasting in the intravaginally-administered gel group than in the IV group.