Tranquilizers can have variable effects on behavior, even in the same horse from day to day. | Photo: Erica Larson/The Horse

Mary Alice, Rhode Island

A. This is a great question. The general issue comes up quite often, both in regard to performance and pleasure horses. In our particular practice, it is most often stallion owners who consider using tranquilizing drugs as an aid to handling stallions in the breeding situation. I do have an opinion on this, but it requires some explanation.

In general, for most situations I might recommend carefully considering tranquilizing a horse for work or breeding only as a possible alternative or adjunct after other behavior modification methods have been tried. There have been rare instances in which we judged their use effective, but usually not. There are many reasons. On light sedation, some horses actually seem more likely to kick or “explode.” Their behavior often is less predictable than without tranquilization. Sedation impairs the horse’s ability to perceive the environment and to react accordingly. This has obvious benefits and risks affecting safety of people and animals. For example, for breeding stallions, it is rare that you can reliably achieve a level of sedation that significantly enhances handling without having a stallion so wobbly behind that he risks falling when he mounts a mare