This issue happened to me so many times, and I only have my dogs since last July.
It's really annoying, and you can't really do anything against it. I have tried everything from yellow bandana on the leash to 'DO NOT PET' sign, but people don't care, and most of the kids running towards the dog can't even read because they aren't old enough for school yet. Otherwise, none of my dogs have issues with children or anyone else, but Maya (the older one) is so playful, she wants to play with every, but she plays rough and jumps all the time. She can easily knock that kid to the ground just like Lucius could.

On a side note: I'm really interested about Czechoslovakian Wolfdogs and enjoy reading more about them! After this post, I'm going to check your past blog posts to see what it's really like to live them. It must be amazing.
I'm glad your son helped me find you!
And both your dogs look​ fantastic!