Stallions are male horses that are over four years old. Stallions are mature male horses that could be of any shade depending on their breeds. Stallions are not always black, rather a variety of colors depending on their registered breeds. Are Stallions Allowed To Race? Stallions are allowed to race as long as they meet the specific requirements when it comes to age, health, and performance evaluation. You must be familiar with the requirements that your stallion must fulfill to be allowed to race. Depending on the specific competition that you will be joining, age restrictions may vary. In general, horses are allowed to join races once they reach 24 months or two years old. Some prominent competitions are age-restricted, in that they only allow horses aged three years old to become participants. These shall test the stamina, intelligence, temperament, and overall capabilities of stallions whether they are competent enough or not to join races.