Teaching moment for the kids then. Kids who abuse animals can grow up to abuse people. He could be afraid of the other dogs too or maybe needs to go to the dog park for play and exercise if you aren't doing that. Depending on kids ages, that's something they could help with. Teachable moments. Just for what it's worth.
I care for a feral colony of cats, not by choice, got stuck with them. One came back home years after someone took him as a kitten. He spent his life on the streets, nearby but on the streets. A young couple sort of adopted him when he hung around their street. It had to be them who did this as I can't do anything with him, not even get him in a carrier to apply flea stuff. He knows when he is sick he needs to eat separately as medicine is in his food and he gets better. The kind vet knows of the cat and the colony and will sell me antibiotic for him. He knows how many days he eats like that. This young couple used to come by regularly to check on his but as young people do they disappeared. They can get the flea stuff on him as he seems to have a minor trust in them. Someone apparently came by recently. It had to be them and put something on him as he looks so much better and he's happier since he's not being eaten alive. Oh, I've tried to drip that stuff on him but he runs from me. The neighbor who helps me with them suggested we might have to put him down this winter as he is old and we are not sure he can make it through another winter. I told her yesterday that there's people looking out after that cat besides us so we need to be careful in our choices. If he's really ill and not getting better then yes. But someone actually loves that old scrappy cat.
Point is - trust. It takes trust.