Thanks all - I remember getting a wee sample from my old boy Sooty (RIP). Nothing could have been easier then, as he had a really simple morning routine: breakfast - let out into garden - wee - come straight back in. So all I did was follow him down the garden, wait for him to squat and I snuck up behind him and stuck a saucer underneath
He was so hard of hearing he didn't even notice.
Fortunately I do also have a dog crate so if the worst comes to it I can isolate him until he does a wee - better than him having to stay in the vets to get one!
Geoffrey has just had a spot of lunch so at least he's feeling a little better than earlier on!