Plot hole: Immediately after Seabiscuit injures his leg, the track vet tells owner Charles Howard that the horse will never race again. He offers to euthanize Seabiscuit, even though it was not a life-threatening injury. Even if Seabiscuit was unable to race again, a champion racehorse has more value as a stud horse. It is nearly inconceivable that a random vet would suggest this so early on. If anything, it would be "wait and see."