Female dogs opt for less yoga-like squatting postures than their male companions, who can sometimes be seen with their leg so far in the air they seem about ready to topple over. It turns out that the height to which male dogs raise their leg has a lot to do with their body size, where they are, and who’s around.
All canines use urine to mark their territory, but some do it more than others. All male dogs, big and small, raise their leg to pee or scent-mark much more frequently in the fall than in the summer, likely because it is mating season. Accordingly, the frequency of their urination increases whenever there is a female dog or a male competitor present. Males will sometimes even raise their leg when their bladders are empty, performing what is called a raised-leg display. Females mark their scent much more often when near their nest or den, and males mark theirs more frequently on unfamiliar objects and places.
The height to which they raise their leg also seems to have to do with getting a mate, defending territory, or intimidating other males. Male dogs raised their legs higher when near the edges of their territories, or when they were with their mates. But proportionally, littler dogs raised their leg much higher than their big friends. Perhaps this is their way of making themselves seem larger, like a bettawith its fins or a cat with its fur.
All we know for sure is that they look pretty silly to us.