Fat stores gained in summer are meant to be used in winter
Horses and especially ponies tend to gain weight during the summer months unless they are kept on an extremely controlled diet. According to Dr. Carol Michael, that is not necessarily a disaster. As long as they are given a chance to burn their fat stores during winter as they would under natural conditions. For Dr. Michael's Welsh ponies, that means living out as much as possible and being allowed to grow and shed their coats in a natural cycle.