Our puppy, a Pembroke Welsh Corgi, is almost 4 months old. She was doing really well with potty training and had almost no accidents. For the last few days, she has been both peeing and pooping in the house if we don't keep her in the puppy playpen or her crate at night (for sleeping). Today I had her out three or four times in the yard, and took her for a walk around our development once. The last time she was out, when she came in she went right to the cat door (we have 2 cats) and went thru to the screened patio, where she peed on the indoor/outdoor carpet. Our cat litter pans are out there and have been since we got the puppy so that she wouldn't get into them. MY QUESTION: what could have happened to cause her to start peeing/pooping NOT outside, but somewhere inside or on the screened area? Any suggestions?