You need to stop taking him to the dog park. It is not fair to the other dog owners to keep taking him back there. I take my dogs to the dog park so that they have positive experiences with other dogs to keep them socialized. If one of my dogs was attacked by another dog which had gotten into fights four other times, I would be very upset.
Lila mit der Floppy-Ohr
Teddy the Fearless
Chaz the Spaz
Pokey - you don't know what you've got 'till it's gone
Zoey - may you catch the UPS man
Auggie -may you find the peace you never had