Okay - pain - in addition to obvious lamenesss, elevated heartr ate. Of course, you need to know what your horse's baseline is at rest and at work. This really is a great pain indicator, however.
Flies: switching tail, fussy head, rippling skin, stomping. Being asked for too much too soon or at a bad time: resentfulness, non-responsiveness or less responsiveness than is the norm. Illness: elevated temp (again, you need to know his norm), loss of appetite, listlessness in a normally alert horse... I'm speaking of before illness becomes obvious and acute. Poor saddle fit: pain on palpatation. reluctance to go forward plus the very obvious bucking, bolting, etc. Just having a bad day? well we all have one now and then. And for me, sometimes my horse is having a bad day because I am having a bad day. Nancy
