To the point.
Yesterday I rode my 6 year old thoroughbred, just plain excersize and jump practice and she seemed fine, no lameness or sore anywhere.
It was raining a fair bit today so I just lunged her for bit (very soft grass) and she seemed lame when trotting. I checked all her feet, cleaned them out etc etc, and I found on one of her front (can't remember which side) frogs had a split or crack from top to bottom.
I should also include her frog is very close (if not sitting right on) the ground. She has very sensitive feet and feels pain when even walking on a road,dirt and rocks without shoes. She's not shod at the moment her feet are growing as she had a fair bit of her hoof ripped off when a shoe was stuck.
Any help I would really appreciate