HISA, the Federal Rules Every Racehorse Runs Under

Before 2020, American Thoroughbred racing was regulated state by state, which meant medication rules, safety standards and even riding-crop limits could differ at every track a horse shipped to. The Horseracing Integrity and Safety Act of 2020 created a federal body, now called the Horseracing Integrity and Safety Authority (HISA), to write one set of rules instead, and it now runs at 41 tracks in 19 states.

The riding crop rule is a good example of what "uniform" actually means in practice: a crop must be soft-padded with a shock-absorbing tip, no more than 30 inches long or 8 ounces, and a jockey is limited to six strikes on the horse's hindquarters, no more than two in a row without giving the horse at least two strides to respond. Before HISA, a rule like that could vary by state; now it is the same at every covered track.

Furosemide, sold as Lasix, is a diuretic used to control exercise-induced bleeding in a horse's lungs. It had been banned race-day under HISA's medication rules. In May 2026, HISA's board voted to permit it again within 48 hours of a race for most covered horses, based on its own furosemide advisory committee's finding that the available evidence does not support the idea that the drug is performance-enhancing. Two-year-olds and horses entered in stakes races, including the Derby, Preakness and Belmont, keep the tighter restriction. A past-performance line or a program's medication notation (commonly "L") still tells you whether a given horse ran on it.

None of this changes how a bet is placed or paid, but it shapes what shows up on the board and in the program before you bet. A scratch tied to a veterinarian's pre-race inspection, a medication notation on a past-performance line, and the riding crop rule's effect on a stretch-run finish are all downstream of HISA's rules now applying the same way at every covered track, rather than differing by state the way they used to.