To me being a reactive human dog owner is one that has missed opportunities to calmly and gently get potential problems under control in the past. Because the owner has not been leading the way and allowing their dog to feel safe, the dog starts to make some decisions and actions that us, humans, won't be totally happy with. When the opportunity to correct this has been missed in the past, it appears to force the humans into a reactive role. To your dog this does not command respect or obedience, because the human appears unbalanced or terribly inconsistent in their rules and communication. Remember reactivity is something that appears to come out of the blue for absolutely no reason to the canine companion.
Being proactive is more about knowing your dog and preparedness. It's also about not glossing over behaviors that can become problems in the future. Even if they are cute and not problems now, the proactive owner will find training and/or management solutions to proactively prevent something from getting worse or happening at all.
As in poker, certain dogs have "tells" when they are about to react. My dog, Boris, wags his tail very fast if he has been told not to do something, but still intends to do it . For each dog their "tells" are different. Some people try to major in the minors with strict rules of canine communication, but the truth is that this communication can vary among the individual personalities of dogs. Statistical generalities can be made to try and predict future reactions, but remember that dogs are individuals. One dogs striping along the back can be aggressive, while anther's can be excitement at meeting an old friend.
You can use what you know about your dog and their "tells" to correctly navigate them around corners. For instance, if you dog pricks their ears and tries to stare down a dog before becoming reactive, you can use this in your training program to redirect that interest to obedience and calmness instead (with the right professional dog trainer, of course).
The proactive dog owner prevents future problems from occurring. The reactive dog owner flirts with the dangerous possibilities of not being prepared in the future. Which one are you?
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