My dad's bedlington x whippet does this and it is hilarious to see. She evn kicks up her back heels when she's finished; just like a dog!
Mind you, we're just waiting on Eilidh doing the same as she has taken to sniffing walls and lamp-posts and has begun to scent-pee. I wonder if it's living with males that does it?
Pearly does the kicking-leg thing too! And sometimes she does it when she hasn't even had a piddle. Maybe she's really a boy trapped in a girly body.....
Our lurcher Dusty don't really lift her leg but IF she finds a "Fantastic" smell up a tree she will try and cock her leg or better still get her butt as close as possible up the tree.