Detomidine has proved to be a useful sedative for horses, facilitating routine tasks like farriery, dentistry and clipping, as well as more involved veterinary procedures. Although it can be administered by injection, the use of a gel formulation applied under the tongue and absorbed through the mucous membranes has become popular.
Some horses may resent application of the product to the mouth. Gel that is swallowed is less effective as it may be broken down by enzymes in the intestinal tract and metabolised in the liver before inducing sedation.
Reza Seddighi and colleagues at the University of Tennessee, have been evaluating the sedative effects of administering the gel onto the mucous membrane of the vagina.
Six healthy adult mares were included in a randomised, crossover study.
Each mare was studied on two occasions a week apart. On one occasion each mare received detomidine (10µg/kg) by intravenous injection and on the other by applying the gel intra-vaginally (40µg/kg – the manufacturer’s recommended dose for sub-lingual administration).
The research team monitored the effects – including degree of sedation, distance of muzzle from the floor, ataxia and heart rate. They also collected blood samples at regular intervals to assess the concentration of detomidine and its metabolites.
They found that sedation lasted longer and was deeper when the detomidine was administered intra-vaginally compared with intravenously.
They conclude that detomidine gel administered intravaginally is a viable method for detomidine gel delivery in mares. They add that further work needs to be done to determine whether changes related to the mare’s oestrus cycle might influence the absorption.
For more details, see:
Evaluation of the sedative effects and pharmacokinetics of detomidine gel administered intravaginally to horses.
Seddighi R, Knych HK, Cox SK, Sun X, Moorhead KA, Doherty TJ.
Vet Anaesth Analg. 2019 Jun 17. pii: S1467-2987(19)30161-8.