I have a 3 year old pomeranian/ shih-tzu mix. The first year I had her, we lived in a one story apartment. It took a while to potty train her initially, but once we did, she did not have accidents. Then we moved to a two story townhouse apartment where she began pooping on the stairs occasionally, and she would pee by the front door on these days. A little over a month ago, we moved in to a two story home. Up until today, she had not had any accidents to my knowledge. To me, the most frustrating part of this is that she gets plenty of time outside and she seems to understand perfectly that being outside is for going potty. If she has to go, she does her business very quickly once she gets outside. I take her out in the morning before work, come home at lunch to take her out, take her out after work and then usually a couple more times before bed. We have a fenced in yard, but I still watch to make sure she is doing her business, which she is. Today, I took her out before work where she both peed and pooped. So I let her have the run of the house until I got home at lunch time (4 hours later). When I took her out at lunch, she wouldn’t go pee (she usually does), so I went to gate her in the upstairs bathroom. Our policy is if she goes potty, she can stay free in the house. If not, she is gated in where I know she won’t go. On my way up the stairs, I noticed poop. It was solid, so I don’t think it was an emergency since she had just gone no more than 4 hours earlier. Thing is, she ONLY has poo accidents on the stairs. No where else. I really don’t want to have to gate her in all the time, but why is she doing this when she is going outside enough?