Sorry - reporting this as previous typo made no sense at all.
He is a relatively well behaved (for a terrier) Irish terrier. We have a conservatory/kitchen where I shut the dog up when I go out, and recently he's started cocking his leg against chairs. This morning he was left for 10 minutes, and I came back to find a big puddle. He's house trained and never poos in the house, but seems to do this to get attention/to express annoyance at being left. I have the specialist pet spray to break down the smell, I clean it with biological washing powder. I just want it to stop! Do I have to shut him in his crate every time I go out? Please help with advice or tactics.