PHILADELPHIA — A central Pennsylvania racetrack is asking state officials to investigate a New Hampshire horseman after 10 of his horses were euthanized on the track in 13 months — two last week alone.

Penn National Race Course jockeys have refused to ride this week on or against horses owned by Michael Gill.

Penn National says eight Gill horses broke down last year and two more last week. Several jockeys tumbled Saturday when Gill's Laughing Moon collapsed after a third-place finish.

The track's letter Thursday to the Pennsylvania State Horse Racing Commission requests immediate action. Commission spokesman Justin Fleming says it's not clear if decisions will be made by Wednesday, when four Gill horses are scheduled to run.

Gill has not returned messages this week.