Why? Were they bit? The only way to transmit rabies is through the saliva of an infected mammal. If anything, and the boys formed a train on the donkey, they'd have to check them for human STDs as they all could have shared one. The donkey won't contract any of the human STDs because ... well ... it's not human. And how did they know the donkey had rabies? There's only one test for it ... examining the brain of an animal ... and that's a one-way trip. So many questions.....