I hope there is a positive outcome to this.
I know what you mean about authorities being no help - my parents call animal control at least 2x a month on their neighbors who constantly buy new dogs because they kill off the old ones and "accidentally" always having a new litter, with all these dogs and puppies being kept in awful conditions (hence all the deaths). The county system there is just plain AWFUL and they do nothing to stop it.
Anyway, enough with the negativity!! Best wishes to your neighboring pooch!