I've always wondered why some don't.. but I guess its just what they prefer.

Ethan is around three years old, and has never lifted his leg when pee'ing except for in the winter sometimes.. and thats only because he doesn't want to get his feet dirty on the snow.

Skylar is 8-9 months old, and he also hasn't ever lifted his leg.

Both dogs basically grew up around Frisk, and Frisk lifts his leg every time he pee's...

I really don't know when Ethan and Skylar were neutered (they were neutered before we adopted them)... but Frisk was neutered at 6 months I think (its been so long ago!).

Hmm... I'm not sure what plays a part in if they lift their leg or not..