A veterinarian told me this story.
When butazolidan was first permitted to be used at the track, the typical dose was one large tablet.
One of the stable lads figured if one tab was good, then two a day would be great.
The “overdose” caused the bone marrow in the legs to erode.
The stress of racing on legs with no bone marrow resulted in broken legs.
The trouble at Santa Anita sounds eerily similar.