If it seems your cat is bored with his/her toys than get new toys but don't just leave them out for her to play with. If you leave them out she will get bored instead only keep them out for a small while and play with her. Though sometimes if you are at gone than leave a small ball for her to play with while your gone. That will keep her interested in the toys.
My cats always loved my Lab and he was very gentle with them. When he passed, I really think the cats were depressed.
Last fall I got a Bernese Mountain dog and he is great with them also At 9 months old, he can be a crazy "big" puppy, but he is always gentle with the cats and they love him too.