What does the veterinarian think? Purina has a good food for helping TB’s with muscling the top line. . I cannot think of the name right now, but it is fairly new to them, like a year or two old, I think. Some TB horses look skinny when all they need is nutritional help for the toplt line, and others look ribby when it is a lot of fat between the ribs giving that look; but I don’t expect that with a TB. . Sorry if my posts look weird as I’m using my phone and it doesn’t play nice when I try to correct or delete something.