In Islam a dog is unclean yes but still a creation of Allah. dogs being unclean doesn't mean they are to be abused..Audubillah!In fact there is a hadith of a prostitute who's sins Allah forgave simply for her act of giving water to a thirsty dog! This is nothing to do with religion..I'm sure the same kids would abuse any animal given the chance..just pure sick minded beings who may very well be a chip off the old block!