I know that a dog sniffing another dog’s ass is the dog equivalent of a “greeting,” for lack of a better choice of words. But what information is my dog getting from another dog’s ass? Sex? Age? Fertility (if it’s another bitch)? How aggressive he is?
Dogs have an acute sense of smell, and I think a lot of their social interaction revolves around scent. My WAG is that sniffing each others butts gives them all of the info you posited…the health, mood, disposition, possible mating behavior (such as ‘this female has been mated by another male’ or ‘this female is ready/not ready to mate’) and ID of the dog in question. It also might have to do with determining alpha/beta roles as well.
I’m carefully avoiding all of the obvious jokes here…I hope you will appreciate the restraint and what it’s costing me. 
-XT
You missed one. 
I didn’t think anyone would see that one. 
-XT
It is best to think of a dog as a mobile support unit for a nose.
… inside which it is too dark to read.
Yeah, that’s a good way to put it. I was amazed to see just how acute the sense of smell is in some breeds of dog. Amazing. There was an episode of Mythbusters that dealt with how dogs can track via scent.
And as a side note, if given half a chance I would love to say Hi! to Kari in accordance with the customs of our canine friends…
-XT
I think it is more of a greeting. For an examply, i have two female terriers. After they fight over something, they carefully sniff each others butt. Or sometimes if they havent seen eachother in a while, if one walks into the room, the other will sniff its butt.
Maybe im wrong, but why would one dog care if the other had been mated, or are ready for sex? They are both bitches…crazy bitches.
Yet, I saw them on another show where the dog of one of those guys seemingly mistook his partner for him because of a (visual) disguise–and they were standing next to each other.
The dog is just sniffing the smelliest part with the easiest access. Just a guess, cuz why else would a dog sniff my old man’s ass when he is sitting down.
Besides hormones and pheromones, it also indicates what a dog has been eating. Has it been eating the same as the rest of the pack, or is is a stranger that wondered in and is up to no good. Their is actually a large social ritual to it all. Just how, when, and who sniffs whose butt all indicates rank.
Oh and mating a bitch does nothing to reduce her receptiveness to the next dog. There is a good reason why it is so insulting to call a female human human a bitch. Many backyard breeder think they can relax once their bitch has mated with a stud. Not so, she is as ready to go as ever.
Not a new Percy Sledge song, eh? Hmmm.
This has come up before, and was well answered by yabob. The lyrics to [post=2495221]“The Dogs’ Party”[/post] explain it best.
Dogs have anal scent glands. These are supposed to provide unique identifiable scents for members of a species.
Damn, beaten to it.
IIRC, dogs (and several other species) have glands that produce a strong characteristic, personal smell. Skunks are an extreme example of this, they have expanded the glands, smell, and ability to squirt to an extreme. If you’ve ever seen especially the little dogs dragging their ass around the floor, they probably have an infection in these glands and this is how they scratch it. Infections of these glands is something that vets often deal with. The glands secrete some of the smell onto outgoing deposits, thus also helping to “mark” their doggy territory with a personal identifying scent.
So a dog sniffing another dog’s rear is getting a “this is who I am” scent directly from the horse’s mouth, so to speak.