Preparing breeze-up horses for sale is a fine art. Racehorses need to be fit enough to race, yearlings need to look amazing for the sales ring. Breeze-up horses need to be fit enough to run, in good condition for the sales ring, and stay sound enough to continue on to become successful racehorses.
Large quantities of feed, particularly feed with high starch levels, can cause muscle problems and highly strung temperament. This can be detrimental to breezing times, as the horse burns too much nervous energy before doing its piece of work. These horses also have an increased incidence of muscle problems such as tying up.