Wow, I hope charlie is doing ok. Understand what you are feeling. My sparky was attacked in his own fenced in yard once. A pit bull jumped in the yard and attacked both my 'kids'. Made me wary of pits and i am careful of what dog i expose Sparky too. Of course, My Sparky says...Mom, i won that fight. I will win the next one too. Oh dear, a jack russell has no fear.
Just be on your guard and watch and see....about all you can do