How can we stop our recently adopted adult dog from acting out by going to the bathroom in the house?

A few weeks ago, we adopted a beautiful 4-5 year old white husky who had been abandoned. The first thing we did was take her to the vet for a physical. According to him, she is four or five years old, and was significantly underweight, but otherwise physically healthy (although we’ll be taking her in this coming week for blood work and to verify/update all her shots). She’s a VERY sweet and loving dog, who seems genuinely grateful that someone picked her up off the streets (we live in Las Vegas, and she was abandoned in June when it’s 110° outside). She’s sweet, friendly, loyal, and has been a perfect dog so far… *except* when we go to bed at night, she gets upset that she’s been left alone, and acts out by going to the bathroom in the house.

We understand the mentality of the dog as a pack animal, and have been taking the appropriate steps to assure that she is calm and submissive (which she seems to be) so I don’t think it’s a dominance play. She’s never done it in front of us, and she doesn’t do it when we go to work. I also don’t believe it’s just that she has a hard time holding it overnight, as she whines when we leave her downstairs to go to bed, and then seems to go within an hour or so.

It typically seems to be urine, although just last night she defecated in the house for the first time. We’ve tried limiting her water intake, and cleaning the marked areas with pet stair remover, bleach, and food grade sanitizer. We’ve also sprinkled a very small amount of ceyenne pepper in the areas where she’s gone (sniffing the spice is supposed to be unplesant and create a negative association with the spot). When we find it, we drag her to it to firmly tell her “NO” before taking her outside; and she obviously knows she’s in trouble and seems ashamed. But nothing we’ve done has seemed to have any impact. We haven’t yet limited her food access, as we’re still trying to put weight back on her, and we haven’t had a problem with solid waste until now.

What’s worse, she seems to be getting more anxious about being left alone for the night rather than less. This behavior has been getting more frequent, and last night for the first time she jumped over the dog gate that we use to keep her downstairs at night and defecated upstairs on the carpet when she found our bedroom door was closed. Honestly, we’d love to have her sleeping on the floor by our bed at night, but we tried this when we first got her, and she marked on the carpet (she distinctly “marked” a small amount on the carpet, as opposed to when she acts out by urinating {a large amount} when left alone at night).

We take her out first thing in the morning, at lunch, right before bed, and often to the dog park once in the evening, and she seems to have normal bathroom habits. Obviously, we’ve been unable to speak to her previous owners (because if we could find them, we’d file a complaint with the Nevada SPCA for animal neglect and endangerment), so we don’t know what her background was, but she doesn’t have any very obvious behavior to let us know when she needs to go out, so I’m assuming she’s never been well potty trained.

We haven’t tried crate training her yet, as I know huskies are a breed that tends to rebel if not given freedom to roam (which may actually be what we’re seeing by keeping her locked downstairs when we’re asleep), and I’ve never had to potty train an adult dog, so I don’t know how effective crate training would be on her, but I’d be willing to try it if I thought it was going to work.

Other than this one (major) issue, she’s been an absolute angel, who we picked up with the intent of finding her owners or finding a new home for, but fell in love with pretty quickly. It’s hard to blame her, as the problem is likely that she was simply never trained properly, but it doesn’t change the fact that we now need to correct the bad behavior, and I’m running out of ideas on how to do it.

Any advice that anyone can offer, or stories from similar situations on what has worked would be very much appreciated!