Tranquilizers for Riding

Photo: Erica Larson, News Editor

Q. What is your opinion on using tranquilizers to calm a horse down so you can ride it? I'm thinking of our son's mare who is a little too hot at this time of the year.

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.

These considerations are just as important when riding or driving a horse. A strong argument can be made that tranquilization impairs the ability to learn. So, if the horse is in training, it might be quiet and compliant, but could be less likely to learn.

Tranquilizers can have variable effects on behavior, even in the same horse from day to day. This holds for both the positive effects and the adverse effects. If a tranquilizer is used, the particular product, dose, and safety issues should be discussed carefully with your veterinarian, who will want to monitor the horse's response closely. This often is not practical for routine use. It is rare that you cannot achieve equal or better results with training or changes in diet than with drug tranquilizers.

My favorite approach to a horse such as your son's mare is to try changing to a diet without grain and with good grass pasture or free-choice grass hay to maintain good, but not fat, body condition. Supplementation with l-tryptophan can also have further calming effects on horses. Regular lunging or round pen work for 15 to 30 minutes, especially before riding, can work wonders at taking the edge off a seasonally feisty mount. It usually gets the horse focusing on the handler and reviews the basic commands.

I hope this is helpful. As you probably expect, opinions vary among professionals on this issue. I'm happy you brought it up and would welcome further discussion.

About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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