bones, as much as dogs seem to love them, not just chicken should be avoided... ANY natural bone should be avoided. not just advice from my big mouth or my vet but here is a website that has pics why you shouldn't and the requisite text why not. for those of you who really need visuals to go along with the pics... look here: http://www.thepetcenter.com/imtop/bones.html
give them dentabones or alternative instead.
cheers. love on you're babies!