I have a quarter horse that I trail ride. I recently tried out a new pad that distributed more weight to the rear of the saddle. That first time left a knot on his spine because of the lacing on the underside of the saddle. It was about the size of a quarter and sore to the touch. He was not ridden for 4 weeks, swelling and tenderness went away. I rode with two pads (not the first pad at all) but again the knot appeared and was again sore. What do I do for this and is this something that is going to be permanent?