One can't have too many massages!  You can determine with Stride / Harmony the appropriate interval for your horse's individual needs and your finances.  However, consider the following guidelines:

For pre-show or event schedules, one to two days before the actual event For recovery, schedule one to two days after a hard workout or event For injury, consider at least 2-3 sessions no more than a week apart, depending on the severity For prevention and maintainence, at least once per 6 weeks