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."
Seabiscuit (2003)
1 plot hole
Directed by: Gary Ross
Starring: Jeff Bridges, Elizabeth Banks, Chris Cooper, Tobey Maguire, David McCullough, Paul Vincent O'Connor
Factual error: Many of the main characters are using modern-day binoculars (black, plastic) throughout the entire movie.
Tick Tock McGlaughlin: No more match races for this little horse because frankly they're all out of matches. Who's he gonna race, Lazarus? I pity these horses.
Trivia: Many of the close-ups in the movie were filmed with mechanical horses attached to the truck with the camera so that the background would look right when you see the actors going by trees.
Answer: They probably do, it just isn't shown. Alternatively, they could have died in-between the time we see the young Red and Tobey Maguire. That could be a contributor to all his anger and rage.