(Information from USTA press release)
Horse identification has changed throughout the years. First, tattoos on the upper lip were replaced with freeze brands on the neck in the 1990s. Now, microchips will take the place of freeze brands and will be phased in over the next few years to include all horses racing at both the pari-mutuel and county fair levels.

Freeze brands on the neck will soon be going away as microchips will be used to identify all Standardbreds for racing in the U.S. beginning in 2021. (Photo by Dean Gillette)
The U.S. Trotting Association (USTA) has announced that beginning with the foal crop of 2019, microchips will be inserted. In addition to identification, microchips are said to read a horse’s body temperature, which could benefit trainers, breeders and owners with detecting changes in a horse’s health. The USTA will require that all horses that race in the U.S. will need to be microchipped by 2021. USTA ID Technicians will be able to insert microchips on current racehorses for a fee of $35. The microchipping fee on foals will be included in the registration fee with the USTA.
For more information on microchipping, contact the USTA offices at memberservices@ustrotting.com or at (877) 800-8782.