I trained a completely untrained German Shepherd to respect cats and my uncle came home with box of kittens and threw it inside the dog house where the big huge German Shepherd was passed out. That big huge mean German Shepherd sure come out of that dog house screaming with his tail tucked between his legs.

Eventually he was completely okay with sharing the dog house with all the different cats. And he was an excellent protector of all the cats there at the family property.