The picture of him watching the squirrel reminds me of some other small terrier breeds as well. For a while some of the rescues in my area were getting dogs I'd classify as feists: a small terrier type, some possibly with a bit of beagle to improve their noses, used as a hunting dog. Many of the ones we got here had tails docked at about half length, like a German Shorthaired Pointer or a Weimaraner, so they were clearly coming from some kind of deliberate program. They weren't just little mutts randomly breeding under someone's porch. One of my friends had one that was a fantastic little verminator. He was able to climb ladders to get up to where critters were nesting in lofts or under the eaves.