Most of my life growing up our family had dogs - my first was a bulldog-chihuahua mix that I gave to my grandmother, but we had labs, german shepherds, beagels, a poodle, a great dane, huskies.
I recall when I met my wife I told her about my love for dogs. I also remember her first comment to me:
"Oh, honey! Doggie meat! You nevah know how tasty!" to which I immediately responded, "Damned straight."
It took a long time to convince her, but we finally got a dog - a JRT, Jack Russell Terrier. It's a great dog - smart, active, playful - and also extremely stubborn.
At a mininum, every weekend, and sometimes once during the week, I take her to the local off-leash dog park. This kind of dog REALLY loves to run around. At first she seemed to have a problem with boxers and pitbulls. She was all the time picking fights with them. Now she seems to get along very nicely with all the other dogs.
Still, she exhibits this curious behavior. She's constantly smelling other dogs' behinds, BUT she snaps at dogs who try to sniff HER butt. "HEY! Whatcha doin back there? Cut that out! Mind your own business!"
It's very curious. Lots of otherwise very pleasant dogs get into fights over - nothing. Sometimes it's a dominance thing - but often it's misinterpretation. See, not all of the dogs are equally well socialized and some have habits that the other dogs interpret as threatening.
Anyway, it's curious and amusing behavior. I've been taking her to that park for over a year now - every weekend, without fail.