Research

Benefits of equine sports massage therapy has been shown to include;

Increased circulation
delay onset of muscle fatigue/tension post exercise
improved stride length
relaxation
stress relief
pain relief
increased body temperature
preventing muscle atrophy
maintaining muscle suppleness

These benefits can help a variety of horses including horses on box rest, equine athletes and horses undergoing injury rehabilitation.

Take a look at some current academic research on ESMT

http://www.sciencedirect.com/science/article/pii/S073708061100284X

This journal looks at the effects of Equine Sports Massage Therapy on the body temperature of the horse and blood circulation, which subsequently helps with healing after injuries.

http://www.sciencedirect.com/science/article/pii/S0737080609005759

Here is an example of a comprehensive review of the benefits and possible side effects of Equine Sports Massage Therapy in areas such as stress relief, pain relief and post-exercise injury recovery.