Well housebroken dog peeing upstairs

Question
Artemis is a 9 y/o lab/bassett mix we've had since she was a puppy.  She is a spayed female and a very calm and stoic dog.  We also live with an 8 y/o beagle mix, Tahlia, who we've also has since she was a puppy.  For the past 6 years, we've lived in a house built in 1847 - it is currently under rehabilitation and we do not live in the upstairs rooms.  Lately, we've noticed that Artemis is wandering around upstairs.  We live in the country, so we keep mouse traps up there, and from time to time she'll go up there to check them out.  Only, there seems to be more going on up there than mouse hunting.  I've noticed 6 instances of urination in the past 2 weeks.  Tahlia is an extremely nervous dog, and when we brought her upstairs to look at the spots, she did not get upset (a big clue that it wasn't her).  Artemis, however, refused to go upstairs (a big clue that it was her).  She has been perfectly housebroken until now.

I've also noticed that she doesn't get excited to go outside and potty anymore.  I have to push her a little bit to go.

Now, we just had her in to the vet for blood work (she had surgery to remove a couple of benign tumors).  The labs came out fine.  I suppose it could be a UTI, but then why is she going upstairs to pee?  I would expect her to pee downstairs...not sneak off to do it.  That's what makes me wonder if it's behavioral and not medical.

There has been no change in work schedules.  My husband has gone back to work after the summer off, but that happens every year.

Answer
Hi Tara, Many thing we consider normal, can upset a dog. First, I would rule out a UTI, she may go upstairs because she knows NOT to go downstairs or it means trouble. Please do not stick her nose in it and punish her. Simply show her the spot and say, "NO, outside" and then walk her outside to "take a break". Taking her out more frequently and giving her more walks at the heel will exercise her mind and keep her more interested in the outside world. You can not assume it is behavioral until you rule out anything medical. Depending on where the tumors were and the type, it could have caused her some kind of imbalance and has her upset in some way. So have a quick urine test done and go from there at retraining her to go outside. Leave me some feedback and a follow-up so that I know how you are doing. Thank you. Regards, Susan