We’ve all been embarrassed at times with our dog’s actions and sniffing butts is high on that list. Of course this behavior is perfectly normal to our dogs and an acceptable greeting to them.
Butts and yes, crotches too, give a dog lots of information about the “smellee.” These areas have highly concentrated odors. A dog’s anal glands, called apocrine, are found on each side of the rectum and their secretions emit strong odors.
Dogs, with their incredibly strong sense of smell, gather lots of data. A few sniffs can tell the sniffer the sex of the other dog, what the dog has eaten, even the emotional state of the dog and whether it is friendly or not. Each dog’s odor is as distinctive as fingerprints are to humans.
As uncomfortable as we are about this behavior, dogs sniff crotches for the same reasons – they impart information to the dog. So keep in mind, though it is embarrassing and uncomfortable to us, dogs are just doing what comes naturally.