HI. I have a 1 year old Male rottweiler and a 4 month old boxer/lab mix. I have been having trouble getting them to share. When I put some ball toys out my rottweiler will always be really possesive with them and he will steal the younger puppies toy from him and guard it. I have removed the most coveted toys but this does not leave very many options for them to play with. Are there any good dog toys that they would be able to share with each other?