(a) A yearling is not eligible to start in a race.(b) A two-year-old horse may not start in a pari-mutuel race in Texas before March 1.(c) A racing secretary may not schedule:(1) a race for two-year old quarter horses longer than 350 yards before May 1 or longer than 400 yards before August 1; or(2) a race for two-year old thoroughbreds longer than 4 1/2 furlongs before May 1 or at one mile or longer before August 1.(d) A horse that is more than 12 years of age may not start in a pari-mutuel race in this state unless:(1) the horse has finished first, second, or third in an officially sanctioned pari-mutuel race during the 12-month period preceding the race in which the horse is to start; or(2) upon due consideration of the horse's prior performance, the board of stewards has given specific authorization for the horse to start.