Maximo started lifting his leg at a very early age. I'm not an expert, but I think lifting is individual to each dog -- some start early, some late, and some never. Training has more to do with stopping it than neutering. (ETA: if it starts early)
I believe Max lifted his leg because his piddle pad was against the fence of his xpen. Now that his piddle pad is free-standing on a rubber mat (no fence or wall nearby), Max squats with one foot raised slightly in the air.
Outdoors, he does the half squat and the full leg lift, which sometimes is so high that he nearly tips himself over like DvlshAngel's Kaji.
