Our 6ish yo Romanian rescue girl has taken to peeing on the floor at night about once a week. We've had her a year, this has only started to happen about 6 weeks ago.
She's been to the vets, no sign of anything untoward, no infection etc.
She might not have been spayed properly - she's going to have surgery to either deal with ovarian remnant retention or be spayed (extremely high numbers on her tests when she last appeared to go into season).
We now empty the water bowl about 8pm and leave a dribble in the bottom so the dogs can wet their mouths but no more. She would otherwise have a huge drink about 9pm, so we're trying to bring it forward.
She is out for final pees about 10pm, DH is up at 6am. From a doggy camera, she puts between midnight and 2am. Always on the same spot, despite cleaning it then using with enzyme cleaner each time.
She's not a dog who has learned how to tell us when she needs to go out, so we just take them both out every few hours in the day at the very least (I WFH), a walk around dinner time and put a few more times in the evening.
Any suggestions on where we go next?