Bringing up this thread with new information. From my friend Barbara D. Livingston's Facebook posts, this happened the last day of Saratoga racing on September 1, 2018:

Famed singer and racehorse owner David Cassidy's ashes were spread at Saratoga Race Course, a track David dearly loved. Trainer Gary Contessa's pony Razor was used for the short service Saturday morning, which was attended by friends and family.


Rider Benito Alvarado performed the honors but his task was not easy, as Razor got a bit worked up. As Gary Contessa said of his longtime stable pony, "He's always been bombproof, but apparently he isn't ashes-proof."


David would have loved that show.


Later that afternoon, the Gary Contessa longshot trainee Sippican Harbor ran in the Grade 1 Spinaway. Gary had looked skyward before the race, asking his longtime friend David Cassidy for a little help, if he could.


Sippican Harbor won and paid $34.