The most intelligent dog that we ever owned was a heeler named Radar about 15 yrs. ago. We could send him to the back of our pasture to bring the roping steers up by himself. If we were out in the pasture with him we were working or pushing the cows up, he would look at me and I would point at which cow I thought he needed to nip and he was right on it. Also, he would correct other dogs that would get too aggressive with the herd. He had a scar on his snout where his mother corrected him, I guess thats where he learned it. He loved people but would not tollerate a stray dog in his yard. Ol' Radar took care of business and ran the place.
