My bunny Theo’s doing the same thing! However, I didn’t move. All I can assume with Binx is that he’s stressed from a brand new environment and the dog, even if he does get along with them.
The only thing that’s changed with me is that I haven’t been home nearly as often as I used to be.
I feel your pain!

Posted By binxesmom3 on 3/30/2017 1:37 PM

I have looked into this issue for about a year now…I love my bunny Binx. He is a 2 year old Holland lop and is a sweetheart who loves ear massages. However, since we moved into my new house he hasn’t been himself. He has stopped using his litter box for a good amount of his messes. And in addition to that he has been leaving wet poops all over my floor about three times a week. He has been on the same food for his whole life. Nothing really has changed in our regiment, besides us getting a dog. He enjoys our dog, Moose, and will lay with him often. He used to have free roam of the house however since he has been pooping everywhere I have had to keep him locked in the bedroom with a baby gate. I have tried locking him in his cage for a few days so he would get used to just the litter box, that worked for a week or so but has stopped. I have tried cleaning his litter box more often so that it wasn’t full. I am at a loss as of what to do right now. We love Binx bunches, we would love to find a solution or at least look for some support from others who have gone through this as well! 

Getting a dog is a massive change to be fair as is moving home. Then to top it off, locking him in one room when he used to have more freedom isn’t going to please him. Maybe the presence of the dog and moving home is what triggered this behavior and it’s just escalated. You shouldn’t lock him in his cage, that’s really unfair. If you want to confine him to restart litter training, he should at least have a play pen.