Why do dogs sniff when they need to urinate and what would be the exact reason they sniff?
They are marking their territory. They will either smell another
dog's urine and urinate over that or, they will mark their own
territory such as the backyard/frontyard, etc.
it tells them that that is their territory. if one dog, wolf,
... sees anouther dog mark its territory onto theirs, it will
usually start a fight. think about this example to help you
understand if you get a glass of milk and you take a drink, that
cup is your territory until you are done. lets say your little
brother or sister comes into the room and takes a drink out of your
cup. you get mad because that cup is your territory. it is the same
thing with dogs, its normal.
What dogs smell, whether it's urine or another dog's butt, tells
the dog just about everything about the other dog. Dogs have
millions more scent receptors than do humans and they way the
process smells is very different than we do. For dogs, scents are
comparable, almost, to how we perceive things by sight. The smell
of another dogs urine tells them everything about that dog -- it's
sex, whether it's in season, whether the other dog is healthy or
not, etcetera. Once they determine what the scent is telling them,
they pee over it to mark the territory as their own or just to let
anyone else coming by that they were there, thus leaving their own