Potty training stubborn 16 month old dog

I have a 16 month old black lab/Australian shepherd who is too smart for her own good. She has graduated from puppy obedience, picks up tricks and commands in under 5 mins and understands complete sentences like "where is your toy/ball/bone/etc" and "are you hungry." She is a handful to put it mildly, I have definitely had my work cut out for me since her previous owner did not do a thing to try to train her, then blamed her when she didn't automatically understand what she wanted, hence why I now have her.

She was especially hard to house train, I imagine since the previous owner just put out pee pads everywhere. She was actually doing very well, no accidents in the house for over 6 months now all of a sudden she's peeing EVERYWHERE. It's not like she doesn't go out, I let her out first thing in the morning, after every meal, before I leave for work, first thing after I get home from work and right before bed. This last week, she has peed on the floor at least once a day for 6 days straight. She peed on her own dog bed, on the carpet, on a door mat and on the hard wood floor atleast 4 times. It seems to be just after I've let her out when I get home and before I feed her. She's already gone out so it's not like she's really got to go. Usually she hasn't even made it to the water bowl yet so she's not fully emptying herself when she goes out.

She has ruined our carpets, our couches, our bed, our hardwood floors (which were brand new last year..), several dog beds and mats and 2 duvets. If this doesn't stop she's going to have to find a new home. Everyone is upset at this situation and I'm the only one who is keeping her in this house at the moment. My father in law tells me regularly that she's "a nice dog but it's gotta go" and he's not kidding. I'm at the end of my leash myself and running out of options. The next step for her is the want ads.

If anyone has any suggestions or thoughts, please help! She has been vet checked and is healthy, she is spayed and normally obedient in every other sense. She is very high energy and can be walked 15 times a day and it doesn't do any good so please don't suggest that.

Thanks!

Did the vet specifically test for a urinary tract infection, keliza? That sort of inappropriate urination is often caused by either a UTI or by spay incontinence, although spay incontinence usually looks more like an inadvertent leakage of the bladder than a squat and pee.

If a physical cause has been ruled out, then start over from the beginning with the potty training. Crate her when she's unsupervised. When you're home , tether her to your belt so you can keep an eye on her and treat her as if she's a puppy. Watch her closely for signals. Interrupt inappropriate urination with a throaty sound and try to get her outdoors to finish--then praise. When she pees outside, praise. When she asks to go out, let her out, then praise when she pees. Just like you would with a pup.

Both labs and Aussies are very high energy and walks will not do it for her. Do you have a place to exercise her off leash? Somewhere she can really run? If not, are there agility or obedience training courses you can sign up for? Keeping her physically active will keep her lab half happy and keeping her mentally stimulated will appeal to the Aussie. :D

Good luck with your girl. Please keep us posted. And if you have questions, please ask. I'd hate to see you have to rehome her.