One of the characters explains that dog racing tracks used to use real rabbits to get the dogs to run faster. But no mention into how that was done, and no rabbits are harmed in the book.
The basic environment for the story takes place in a national competition where young men, teenage boys, walk. But if they stop for too long, or walk to slow for too long they are shot and killed. Also there is a part where the main character is remembering is mother hitting him really hard across the face.
There is a story from one of the more prominent characters that he tries to engage his girlfriend in sexual intercourse and she becomes terrified and attacks him. Rape doesn't occur in the story, however.
There is a lot of gore described, but it's necessary to the story line. I don't watch or read gory movies, shows, or books, but this didn't bother me because the story wouldn't work without it.
Nothing with fingers. People are walking from the most Eastern part of the state of Maine USA, and some make it to Massachusetts USA. People's feet are in really bad shape at times, and the main character talks about his feet and the swelling and the pain. There is no mutilation though.
The walkers are teenage boys, and there are some crude moments in the story. The walkers also talk about young women in crude manner at times, and there are parts where an event which occurs is either a sexual event, or the main character feels it is sexualized. No minors seem to be sexualized by adults, however.
it is possible and implied very lightly that one of the young boys may be gay, and well everyone but 1 of the boys in the book die so that makes this a possible thing