Even if your pup gets the best start in life, he will still likely develop some “problem” behaviors as he grows up. We put the word “problem” in quotes because most of these behaviors are natural and normal dog behaviors, but they are not welcome in the human world. Behaviors like jumping on you as a gesture of affection, nipping at your hands as an invitation to play, and sniffing you in inappropriate places are all perfectly acceptable behaviors for dogs to do to other dogs.
Martingale collars (also called limited-slip collars) are usually made of flat nylon with a smaller fixed-length section (made of either nylon or a short length of chain) that, when pulled on by the leash, shortens up tightening the collar around the dog's neck, to a limited extent. When properly fitted, martingales are looser than flat-buckle collars when not tightened, and less severely corrective than slip collars when tightened.
Herding breeds like border collies are the masters of this game, which is why you’ll see a ton of them at trials, but they’re not the only players. Chihuahuas, pit bulls, huskies, hounds, even Great Danes. You name it, my dogs and I have probably been shown up by it at some point. Surprisingly, certain toy breeds like Papillons have a real knack for agility.