Who knows the true value of a person? Or, even a dog for that matter. God has a way of intertwining everything and everyone in such a marvelous way that it just "makes sense".
Here are a couple of Bible verses that make a nice companion to the Snoopy comment...
Proverbs, Chapter 15 (WEB)
but a harsh word stirs up anger.
And
Romans, Chapter 12 (WEB)
21 Don’t be overcome by evil, but overcome evil with good.
Admittedly, this isn't always an easy thing to do, but it works! Remember, practice makes perfect!