I have a 2 year old beagle/bassett hound mix and 2 cats. What I've noticed in the past week is that Casey(dog) is going towards the litter box and sniffing around. Then I caught her last night using the litter box! Is this anything anyone has ever heard of? Also she won't ever go outside to go potty. What should I do about this? Just give in and give her her own litter box? Please help!