Mighty big words. And I have no particular reason to doubt your sincerity. Whether or not such action by you would be justified is an open question.
If your "kid" is in the dog owner's fenced back yard without his permission and tossing rocks at the dog and gets bitten as a result, then you need to blister your kid's butt, rather than shooting the other man's dog.
If you trespass on his land and shoot his dog at a time when the dog is presenting no threat to you or anyone else, then the owner has a right to attack you.
Neither you nor the dog owner has the right to take the law into your own hands.
What is done at a time of actual attack or of imminent threat is one thing. What is done afterward for revenge is something else altogether.
I apologize for the confusion. I was speaking in terms of an attack by a dog upon my child while in public or while upon my own property. I don’t permit my children to trespass upon the property of others.