When Curly yells when Seabiscuit the horse bites his behind, the horse gets startled and jumps.
You can see a wire pulling the towel of the horn Curly is blowing in.
Stooge shorts were more than capable of ending in strange ways but they usually tied up loose ends, if only in a brief moment or two. This short is an exception as the little girl and her mother are completely forgotten halfway in, even after Curly takes the little girl's money. There's never any comment about getting the money the Stooges win back to the two women and they're never mentioned again.