I’m going to go out on a limb (I’ll probably catch some heat for this, which is okay because the message is important) and say that one of the smallest, yet most powerful things an owner can do for their dog is say NO.
Far too many dogs who come to me for rehabilitation of serious behaviors, like aggression, separation anxiety, leash reactivity, food aggression, etc, have already been through training with a “force free” or “positive reinforcement” trainer. The owners are told by these trainers never to use the word no because that word will somehow have a negative impact on the dog. Instead, the dog is redirected from the unwanted behavior and then rewarded. This practice only reinforces the problem, which then intensifies it, and the owners are really in trouble and have no solution, are out good money, and they are totally frustrated to boot.
There must always be balance in life and in dog training—hence the term “balanced” dog trainer. I’m a balanced trainer, which means that I use positive reinforcement (yes, praise & food) along with corrections (no and some form of punishment like a leash correction). If we just use praise all day long, the problem (jumping, nipping, blowing you off, counter surfing—you name it) mushrooms into a massive issue and is never fixed. But, if we simply say NO and use a proper consequence, the dog learns and the issue is gone.
It’s like your teenager getting a speeding ticket. If the parent just pays the ticket, the teeny bopper never learns, but if he has to pay the ticket and loses his driving privelages for a month, then that proper correction caused him to learn.
Saying no to a dog is the precursor to preventing a host of problems, and its also a great way to show them exactly what is expected of them.
The lesson: you must have a balance of both punishment and reward, if you are wanting a well behaved dog.