The kitten is 4 months old and our dog is 2 yrs old. The dog (Abby) was 100% potty trained and never had accidents in the house. All of sudden she started pooing near the cat litter box and peeing. The cat has peed several times to in the house but is almost fully litter box trained. Is she just marking her territory? Will she stop?

You're dog is going where the smell of feces and urine is! Try and place the litterbox where the dog can't get to it. Not only will that help her not potty I the house, it'll also save you from expensive vet visits when your dog decides to sample the cat poop in the litter. That can create a pretty nasty, and sometimes very fatal impaction.

Is your dog fixed? If not you need to get it fixed especially if it's a male dog. It feels like it's home and space has been invaded and it's trying to let the kitten know that this place belongs to it. If you get the dog fixed it should help the situation, but I'm not a vet so I would say consult your vet just to be sure. When I my daughter was born my dog and cat both started to do this as well. Their vet said they were marking their territory as if they would with being outside on a tree.