Why do dogs smell one another's back ends when they meet?

Answer by  Lottadogs (1258)

Dogs check odors for lots of information. From sniffing another dog's rear they can determine the sexual status of the dog, check the health and diet, and check to see if the anal glands indicate the dog is feeling fearful as they release odors when the dog is nervous. All this helps determine which dog is the highest ranking.

Answer by  mesh (351)

Smelling a dogs back end is how another dog can tell where another dog has been. It's a way that they meet eachother. It's typical for a dog to "mark" their territory and this is how they get acquainted with the smells.