I always had cats when I had my old spoo. He used to love the cats and was fantastic with them so I would let them play. It turned from play to hunting after he was about 2yrs old and from them on could never be trusted alone with the cats again. He never hurt them but I could tell it was different. He would stalk the cats as well as just stare at them with a look in his eyes. I don't know what changed but it did and no matter what I did I couldn't change his view of the cats back.
I still have cats and now have 3 dogs. My shar pei, Xin, is so easy. The cats were never an issue with her. Its as if the cats can't see her and vice versa, she couldn't care less. Mercury is yhe same way. The first time he met a cat he smelled him and walked off. The 1st time he met my parents cat Fred freaked out hissing etc and Mercury walk on by. Cat? what cat?
Jupiter is another story. Everything is a chew toy to him so I am having to be firm with him. Sometimes it's not easy because one of my cats LOVES to get him in trouble and Im not always as aware of stuff going on as I should be. Ghost Freat, the cat, teases him by sticking her paw under doors, smacks him with her tail, steals his food/balls, and generally acts like the snot she is. I actually have a command "no cat" which is helping a bit. I think Xin and Merc think Jupiter is a bit odd for being so goofy.