The final and last-quarter race times and racing classes for a group of Standardbreds were analyzed before and after infrared laser light treatment. These horses had either check ligament injuries, plantar desmitis or pharyngeal lymphoid hyperplasia. A 904-nm infrared laser was used to treat check ligaments at 146 Hz for 26 sec/cm2 of affected area, acute plantar desmitis at 73 Hz and chronic plantar desmitis at 292 Hz for 26 sec/cm2 of affected area, and pharyngeal lymphoid hyperplasia at 146 Hz for 5 minutes. Of 35 horses treated for check ligament injuries, 80% had similar or faster final race times, 68.6% had similar or faster last-quarter times, and 68.6% raced in similar or higher classes after treatment. Of 8 horses treated for plantar desmitis, 87.5% had similar or faster final and last-quarter times, and raced in similar or higher classes after treatment. Of 30 horses treated for pharyngeal lymphoid hyperplasia, 80% had similar or faster final race times, 90% had similar or faster last-quarter times, and 70% raced in similar or higher classes after treatment.