I do hope the horses' owners accept the offer to pay for the filly--the dog owners should darn well pay for that poor little horse & some extra besides!
I am disappointed that these dogs are to be kept by the owner. I had a friend who, last year, was out driving her horse & a loose dog attacked her horse as she drove on the road past the owner's house. She got out of her cart & managed to hang onto the horse until the dog's owner got there to catch the dog. Her horse wasn't hurt, just scared (he ended up upside down in the ditch, still hitched to the cart, with my friend hanging on to him) and her harness was wrecked. She had to unhitch and lead the horse home. The dog owner got his truck & hauled her cart home for her. I told her at the time she was much too nice--the owner was all apologetic and claimed the dog wasn't supposed to be loose and he wouldn't be loose again, so she didn't call police to make a report. Now she says she wishes that she had done that--she has driven her horse around home but hasn't driven down the road since. She has learned that the dog that caused the problem is again being allowed to run loose. I would say that chances are good that in this case, too, the dogs will be running loose again soon. Dogs do get off chains by accident sometimes, but not usually two dogs at once--I would say that was no accident, someone figured that it was okay to leave them both loose. I hope that someone (police?) informed the owners what will happen the next time their dogs get loose and attack someone's horses?