A muscle problem can be the cause or a reflection of a deeper cause.
Proper treatment depends upon proper diagnosis and only a vet can do
this. What may be the proper therapy for a muscle can be the improper
therapy for another problem. Sports massage should not be used when a
problem has not been properly diagnosed, there is abnormal heat or
swelling, the horse is lethargic or has a lack of appetite, the horse
has an elevated pulse, respiration or temperature, the horse is weight
bearing lam, or an injury has occurred and it is less than seven days
Once an injury has been properly treated, sports massage can be employed
to restore muscle tissue to its normal function. Sessions should be
light for at least two weeks following a serious injury and first time
massage should not be performed within seven days before a competition
if the horse has not been massaged before.
(Taken from a handout I give when I do massage demonstrations).