My 17 month old dog has developed a habit of going up stairs in our house to pee (he always has acces to the garden). He has done it twice over the weekend, once in the guest bedroom and once in another bedroom. He has never done anything like this before. As a general rule we dont allow the dogs upstairs, but on the odd occassion they do manage it. I am keen to hear whether anybody has an idea why he may be doing this and what I should do about it.

I would first get him checked out at the vet as he may have an infection. If that is negative has he had anything happen to him over the last week or so that could perhaps frightened him or upset him ? Anything that has changed from his normal routine, diet, walks , visitors etc ?

Lucy
xx

It sounds like he is marking his territory. It is an area where his scent is not around. 

A quick solution would be to get a stair gate to stop his access.

Seems to me too that he is marking his territory.  I had a similar episode with my 11 month old male.  He is not allowed onto the sofa as are none of my dogs.  One evening found him on the sofa and he had also peed there.  It happened on another three occassions too.  The only thing I could do was to make sure that he wasn't in the living room when I wasn't there.  I have started making sure he comes with me when I go out of the room and when I am not home, he is confined to the kitchen/garden area.  I have a big big kitchen.  Now he has stopped.  It seems to me also that he was marking his territory.  Luckily I caught him early to ensure he didn't completely ruin the sofa.  I can remove the covers and have them cleaned which I did luckily.

We have a Whippet that does the same. Once they are happy that the territory has been marked, it stops thankfully.