My horse Toby seems to be at a good weight and has fat pads by his shoulders. Recently, I noticed that I can always see his ribs. He is in very good health, is UTD on worming, vaccines and floating, and is full of energy. Is it normal for a horse being worked every day for 2-3 hours to show their ribs? (I also show him every two weeks) He is on 24/7 turnout on pasture.