Hey all - my friend has a 6 yr old neutered Lhasa male that has just started marking around the house - she has been to the vet for a check and had a urine sample checked which was fine. He has always been very good in the house and this is a new thing - he's always had free run of the house and sleeps on the bed but yesterday she caught him cocking his leg on the bed post...and this morning he has cocked his leg in the kitchen...any thoughts or help would be much appreciated :)

i can't say i know why he's doing this but i suggest your friend goes back to basics for a while and keeps taking him outside and praising him when he wees. Try and catch him before he does it in the house by watching him at all times and if he starts sniffing then take him straight out till he goes.
make sure he isn't shouted at for his actions and concentrate on either catching him before he goes or ignoring bad behaviour and rewarding good behaviour.
If he continues to do this then i'd be tempted to go back to the vets again as this isn't normal for him and at 6yrs old he's old enough to know better.
hopefully someone on the site may have experienced this with an older dog and can help more.

There will be lots more experienced help on here but 2 things come to mind.  Check whether there's been ay changes in the dog's life/environment.  Stress of any sort [good as well as bad stress] can bring on this behaviour.  Also, make sure the wee is thouroughly cleaned - use biological washing powder to remove the smell [to the dog they've got much more sensitive smell than us] and try not to let it become a habit.

Both replies I agree with.  Telling him off is a no,no, especially if it's stress induced.  It certainly gives out stress signals in a dog that doesn't normally do it. 

I think your friend needs to have a good think about what change has upset him.  If vet says there is no medical reason, it sounds logical that he is marking because he's upset over something.

It isn't always easy to pinpoint the thing that set him off though.  (rack your brains!)

Thanks for your replies - have passed them onto her :)