my tb mare looks stunning apart fron the rug rubs on her chest she wears a vest to stop it but doesnt seem to be any good and ideas as i want to show her but these look mega bad
change the rug. Get one such as a Fal with no side vents and a shiny lining. I suspect you have something like a weatherbeeta or a Masta which has vents. the vents are frequently in the wrong place and cause rubbing. Failing that turn her out for a week without any rug at all. It will soon grow back and she will cope with the weather.
I had this problem with various rugs and bibs. The only ones that worked for me are Bossy Bibs. Bossy Bibs couldn't be more helpful and delivery was next day. Only cost about £18. Money well spent.