Can anybody please help.  I have a 2 year old bitch who has been toilet trained but every now again would have an accident during the night and would have a wee at the back door.  We could cope with this whilst she was younger because we appreciated her bladder was only small and training would improve with age.  Now at 2 years old this behaviour has only improved if we lock her in our bedroom with us.  If shes locked in the room she doesn't wee but if I leave the bedroom door open, she will go downstairs for a wee. This behaviour is confusing us because she has proven to us she is able to hold on for approx. 8 hours if she needs to. A couple of days ago, my husband got up at 0530 for work let her out for a wee, which she did.  When I got up at 0630 there was a wee at the door.
Her behaviour has started to deteriorate during the day.  She has now urinated on the settee, on my sons bed and twice on her own bed.  She can come into a room where we are and just squats and urinates.  She knows shes doing wrong and runs and hides.  We have taken her to the vets and they did a basic test on a urine sample which was clear but I am convinced it is not a medical problem and its a behavioural problem but I appreciate I'm not a vet. When she is urinating during the day, the back door is open and she is able to get out.  I also work from home, so I am with her all day. 
Can anybody please help.

Two questions , do you or members of the family tell her off when she wees and what we you cleaning the wee with ?

When a dog develops a habit like this it is best to ignore the dog clear the wee up without acknowledging the dog and carry on although it never happened. Also a good way of cleaning the area is use a dilute solution of biological washing liquid as it breaks the enzymes down and reduces the smell which will help stop repeat weeing in the same area.

To begin with we did shout at her but as time as gone by we have been ignoring the behaviour so she isn't getting the attention even if its bad attention.  When she wee's at the back door luckly its on a hard floor and we use flash. On other occasions its the washing machine.  People say its very rare for a dog to urinate on their own bed, which ours has done.

Another tip is to place something where the habitual weeing is taking place eg a box or  remove or move items she is weeing on. It is about trying to break a habit by taking away the triggers or areas that she is using.

I have used this very successfully with my cats so is worth trying.

Is she spayed as if not us she did to come into season soon ?

> She knows shes doing wrong and runs and hides

Dogs don't have a sense of 'wrong' and she runs and hides simply because she is avoiding being told off.  But she won't know what she is being told off for. 

My initial thought was a UTI but it seems that your vet has ruled this out.  There is a reason for her doing this, she is not trying to annoy you.  I would be looking for the reason that she is unhappy about something, and I would be racking my brains, trying to work out what has upset her. Has there been a big upheaval or change in routine.  Work on the house, workman making noises?

If unable to pinpoint her distress I think the only sensible action is to go back to treating her as an 8 week old puppy.  Take her out for a wee every hour on the hour.  And stay with her.  It is no good letting her out and hoping she will go.  With a puppy you would be staying to be ready to heap praise on her.   I would say that it isn't fair to let any dog wait 8 hours for a wee.  Not many adults do that while at work during the day.  I would wet my drawers on the way home if I tried that.

I had a dog who after several years of being completely clean in the house, started to leave a "smelly midnight package" in the kitchen.  The vet checked him over and x-rayed his back, and found he had the beginnings of spondylosis.  I'm not saying that this is your bitch's exact problem, but might be worth asking your vet to investigate a little further, in case "something" is giving her the "gotta go now" signal.

You can get false negatives with urine tests, and they also might not show anything if there is another problem such as bladder stones.  I would want this checking again.  I've had similar problems with my lab for a year now, originally she did have a UTI last July but never since, but has been symptomatic on and off for it.  Her thyroid is a little low, which I'm told can both predispose to and mimic a UTI in some dogs.

Thank you to everybody who has taken the time to reply to my post.  When we took Jess to the vets the vet did say they could do further test where they would go into her bladder and take fresh urine for further test and could also take blood test.  The vet at the time didn't think it was urgent, due to Jess being in such good health and asked us to go away and think about it.
I am almost certain the night time weeing is due to getting into a bad habit, I will completely clean the area as somebody as already suggested and also place an item in the place where she heads for.
After speaking to my husband and racking our brains over any changes we may have effected Jess's behaviour we can only presume its a kitten which we got at Easter.  Since around this time, this is when the spontaneous weeing started but we can't be definite.
Jess is a very affectionate loveable dog, sometimes a little over the top and very possessive towards myself and husband.  She likes to lie on anything belonging to the two of us, will go in my husbands work bag and takes things out, this is when shes not actually lay on it.  She has even weed on his bag lately.
Plan of action is:
1.  Every hour encourage her to go out for a wee and reward with a treat.
2.  In August Jess is going to the dog sitter for 3 weeks..  In the past the sitter has never had a problem with Jess weeing.  We will see what happens this time.
3.  If she doesn't wee there, we will know its behaviour.
4.  If she does have accidents there, trip to the vets required.

Thankyou to everybody.

Glad you've decided on a plan.  :-)

Do please come back and let us know what, if anything happens.  It's always good to get feedback.

If you can restrict access to where she wees for a while it may help break the habit.  Saffi's weeing indoors is partly behavioural - she is capable of holding it, but she won't, and she also forgets to go when she has outside access so she suddenly realises.

I got it under control before the last pseudo-UTI flareup by firstly taking her outside at 10-11pm and making sure she did everything, and then by having a stairgate at the top of the stairs so she couldn't get to the hallway, lounge or kitchen (she'll go kitchen by preference, then the others so I had to completely restrict her upstairs).  In doing that, she got into the habit of holding it so I was able to in effect re-housetrain her.

It's unfortunately gone again now as she's in the middle of a bad flare-up, but it did work very well until that point.