Housebreaking a Rescued Dog

Question
I adopted an 18 month old peekapoo from an animal shelter about 6 months ago.  "Princess", as we call her, had only been in the shelter for a month.  She is a very sweet and loving dog but is NOT housebroken.  I understand she came from a breeder who had several animals and had surrendered them as they were not being properly cared for.  I'm not sure of her previous living conditions and her day to day life, but Princess is very peculiar and has many, many trust issues (she will only eat in the dark; when a new person comes in the room, she urinates).  I have tried settin up a strict schedule for toileting and rewarding her for toileting outside, but she continues to have accidents inside the house. Because of the frequent accidents, I've tried leaving her in the bathroom when I am not home (with her toys and Dingo) but she will immediately urinate as soon as I close the door.  I'm afraid of crating her and am wondering if she is having issues of separation anxiety, but have no idea of what to do for her.  When I am home she is a very happy dog but when I am gone and if I leave her in the bathroom she cries like nobody's business.  So, I have been leaving her in the house, not closed in to any room.  Every day I come home to another accident.  Any advice you can give will be well-taken!  Thank you for your time!

Answer
I would try crating her.  Get her used to the crate, (just don't throw her in and lock the door) ;-) by leaving it open in an area where you spend time when you're home with her.  Do that for a few days and praise her if she explores the crate or especially if she goes in.  If she's food motivated, throw a treat in the crate, but always let her go in on her own, the crate is not punishment, it's her safe, little home.  Put her blanket or bed in the crate with her favorite toys.  She will slowly get used to the crate and see it as her home.  After she is going in, you can start closing the door, but not latching it so she can still come and go.  The thing about crate training and potty training is, slow is fast.  None of this is going to be a quick fix, it is going to take time and if you try and rush it, you won't make progress.

I would also try DAP (dog appeasing pheromones), they're available at most pet stores.  They are supposed to relax your dog.  There are diffusers that you plug in and there are probably sprays that you can spray on her bed and in the crate.  You could also talk to your vet about using a herbal remedy like St Johns Wort, it works to calm some dogs, but as I said, check with your vet first before trying any herbal remedies.

Once she relaxed, some of the fear issues should resolve.  Keep her on the strict potty schedule (first thing in the morning, last thing at night, after eating or drinking and whenever she wakes up from a nap).  Do you have grass in your yard?  Given her living conditions before she came to you, she probably was pottying on concrete, so she doesn't differentiate between the concrete she's pottied on for several months and your kitchen floor.  You need to get her used to going on a different surface and that generally means grass.

Just remember, as I said, in training dogs, slow is fast.  If you try and go too fast, you're just going to undo whatever you've accomplished.

Good luck