One of the most common instruments veterinarians use in equine practice is a nose twitch. For those of you unfamiliar with horses, a twitch is a clamp, piece of rope or chain on a handle that applies pressure to the end of the horse’s nose. The twitch has been used for thousands of years and many thought it simply redirected the pain of a procedure such as an injection from the sight of the actual procedure to the nose. However, it has been shown using the twitch actually releases natural chemicals called endorphins inside the horse’s body, which have a sedative and pain-relieving effect on the horse. Dr. Sue McDonnell at the University of Pennsylvania Equine Behavior Lab says it takes 3-5 minutes after applying the twitch for the endorphin levels to rise and the pain relieving and sedative effects to take effect. Many of us get in a hurry and apply the twitch and then immediately start to work when it might be better to wait a few minutes for the chemicals released by the horse’s body to take effect.
The second concern is the length of time the twitch is effective in pain relief and Dr. McDonnell indicates the twitch is usually effective for 12-15 minutes and then should be removed. The twitch can be reapplied after 15 minutes and should be effective but it may not be as effective as the first application. The effectiveness of a twitch depends on the horse and circumstances involved. If the horse is already excited the twitch is used, the effect will not be as great. If the twitch is applied skillfully and the horse remains calm, the sedative effect will be much greater. So, it turns out a twitch actually causes sedation and pain relief and is not just something to take the horse’s mind off of another procedure.