ours didn't start until 5 months old but it depends on when the dog decides. it could start early, or really late. just be patient.

Some male dogs never lift their legs. usually it will happen before the first year passes. cute story: my dad got me a dog for valentine's day... years ago. he was a boy bichon. when he first started attempting to lift his leg, he would over-shoot the entire manuever and end up flipping over onto his back.... like he was a gymnast. LOL! it was hilarious. he finally got the hang of it after a couple of months. a year later, i got a female bichon for valentine's day. she quickly started "lifting" her leg. of course she could only swing it forward. she did this almost every time she went to the bathroom. those dogs were both crack-ups. i miss them.

My lab is 15 months and he just squats to pee. We're learning to accept it...lol but I'm sure in general it has to do with coordination, puppies are pretty clumsy for a while. It will probably happen soon enough, but it might never start, too...you just never know.

My big old Therapy dog, Bossco, (written about in other answers RIP) had a retained Testicle, of course, he was neutered at 10 months. We had waited to see if the other "boy" would drop...never did...and at about 65+lbs...by 10 months..that was a $400 surgery to snip the one and play seek and find the other! Bossco was "caught" lifting his leg to pee exactly two times in his life. That's it, he was a squatter! Once on a walk at a dog friendly park, where there was a lake to walk around, he very excitedly began sniffing the big trees that lined the lake and the walking path. He kept turning around looking at us, quite animated and excited as if to say, "smell this, check it out...there's pee on this tree a good two feet off the ground here....HOW THE HECK DID THEY DO THAT????? It was pretty funny to watch...he, of course, squatted. In no way does it mean that your male dog is LESS "a Dog" any more than neutering would make him less BOLD or noble in his maleness. It is simply personal preference on his part! My Female Shepsky, Hannah, (my current doggie girl) often lifts a hind leg to pee. She's the first female I ever had that did that. I once read somewhere, and really wish I could remember or find it again...that female dogs have something like 26 different positions they CAN CHOOSE to assume to take a pee! If it's true...that's something eh? I sure as heck can't think of that many I could take! lmao

right at about "puberty" so depending on size 3-9 months

my puppy is 10 months old and still squats, he attempted to lift his leg once and that was when he was 7 months old.

My vet told us that if a dog is neutered prior to learning to lift his leg, he probably never will. Out 18 month old lifts his leg even if squatting, i.e. not against anythig.

My first whippet arrived at the age of 10 weeks, peeing with his leg up.. My second whippet started at 10 months, he still hasn't quite mastered it, he doesn't lift it straight up but holds it to the back often resulting in a yellow stained front leg.