We have a shih tzu/bichon frise who's 10 months old. Mad, playful, lively, loving yada yada yada.....much loved family pet.
However, having been pretty much housetrained for a good few months, the last couple of weeks he's taken to lifting his leg and peeing against bedroom furniture! I have absolutely no idea what to do about it.....he has easy access to outside (the door's always open, or on the odd occasion it's not, he'll stand by it and let us know he needs out) but I don't know what do to about the peeing on the furniture. The bedrooms are all upstairs, and I'm pretty sure I still have a stair gate I could haul out of the loft to keep him downstairs if that would solve things, but I'd be really grateful for any advice anyone with more dog experience than me (not difficult!) could offer any help or advice
Go back to puppy house training basics and if you catch him mid pee, scold him. Buy some biological washing powder and make a weak solution to wash down the furniture he has already marked to remove the scent.
Dog pups get a hormone surge at about his age which is almost certainly what's driving it.