My cat has litter box problems??

I think you're right. Dog food isn't meant for cats. I would separate their bowls, maybe move 1 in another room. Also, the puppy may be wanting to play and messing with her while she's doing her thing and cats like their privacy. Hope you get the problem worked out. Btw, I use ArmNHammer and it's the best I've ever found as far as smell, clumping, etc.