Desperate help for my dog?

Well my neighbors 8 year old son and my dog were playing and my dog came in the house whining and and!! to find my dogs hind area bleeding, the little runt stuck a stick up his ... area because it was blood around the area of the stick and he confessed to doing it why would this type of creepy ual behavior come from a child his age, should i report his parents. Sticking a STICK up a dogs ?!?!? What do parents teach kids these days!?!?