My Cairn, Murph was lifting his leg by 6 mos. Whether peeing or marking, he lifts it.

My Collie, Oz, started lifting his leg around 18 mos old. He only lifts to mark though. He squats for peeing. He's so tall, I don't think he can keep his balance for as long as it takes to pee.

My other Collie, Gull, was lifting his leg by 6 mos for short pees. Although, he doesn't lift it like you would normally see a dog do. He just casually lifts it a lil' off the ground, sort of dangling there still by his side. He's 18 mos now and still doesn't mark. For long pees though, he squats like Oz does. Again I think it's a balance thing being so tall.

Par...