Horse racing is an international sport steeped in tradition, a contest of speed between horses ridden by jockeys or pulled by sulkies and their drivers. Its roots reach back to ancient chariot races and its enduring popularity has spread worldwide. But as horse racing evolves, animal welfare is becoming a central issue. With more and better track conditions, advancements in veterinary care, and efforts to protect the health of racehorses, horse racing continues to thrill millions of fans and capture people’s imaginations around the world.

Racetracks can be found in many cities and towns across the globe, and are often crowded with spectators wearing silks to match their racehorses. The races range in distance from five furlongs (that’s about five eighths of a mile) to one and a half miles. The length of a race can be affected by track conditions, which include whether the track is muddy or dry. In addition, a track’s slope can influence how fast a horse runs.

Thoroughbreds, the breed of horse used for racing, are bred to run fast. The best of them, such as this year’s winner of the Preakness, have a four-beat gait that propels them forward with huge strides and hypnotic smoothness. The horses are ridden by jockeys, who wear uniforms with distinctive silks to identify themselves to onlookers.

Getting a horse ready for a race takes time. Trainers work to make sure that a horse is fit and healthy before the big day, and they often inject them with drugs to help them overcome pain and discomfort. The most important drug is Lasix, which is noted in the racing form with a boldface “L.” It is a diuretic that prevents pulmonary bleeding, caused by hard running.

But critics say that racehorses are abused by being forced to use the drug, and that many of them need other drugs as well to go the distance. Racehorses are confined to stalls from a young age, and the intense exercise of racing can put a lot of strain on their bodies. In testimony before the New York State Senate, a equine veterinarian likened it to locking a 100-pound child into a 4-by-4-foot closet for 23 hours a day.