We do not approach others as blank slates. We make all manner of assumptions about them based on how they look, what they do, what they say. This is especially true when dogs are involved. Those of us who adore our dogs make assumptions about other dog owners — most of them good. It’s called a “fundamental attribution error.”
Many handlers use some word or phrase to alert their dogs that the fun is about to begin. We use “Ready?” Followed by “Now,” as part of our start-line ritual. Sure, it’s important not to catch your dog offguard with your first obstacle command, but the power of anticipation is great.
The average dog trainer is fine for typical pet dog training. Such a trainer probably can help solve typical puppy/dog issues like jumping up, chewing, etc. When you move into the realm of performance dogs, or even dogs who will do more than hang out in the backyard, then I think it’s best to seek out top trainers in your area, who specialize in the various training you need and who really keep up on the latest animal behavior research. When a dog’s challenges cross beyond typical and into abnormal, then it’s time to consult with a behaviorist … especially if the behavior is dangerous.
