At this point I would make multiple copies of everything that has happened in an easy to read format complete with a footnote section that includes all documentation and reports and news coverage. I would then send a copy to your congressman senator, FBI, the various "news on your side" programs almost all the big channels have one, the NY times, and all big papers, Animal activist groups (cant mention names but begins with a P and all the others, a few PI firms (the big ones) shoot even Perez Hilton he does love his little dog and you never know.... anyone with a voice. If you cover enough people SOMEONE will take on the story or the case as there are all the juicy tidbits they love, corruption, fuzzy animal, greed, etc... I would send each one registered mail so that who ever gets it knows you mean business and with a CC sheet that mentions every other person a copy has gone to (this too will let them all know that you are serious and add a little competition to those interested in helping or doing the story.
I am really serious about this as there is no one on the lower levels that is going to help you now you must think outside the box and start screaming as loud as possible as someone is bound to react.
Good Luck. I too will be surprised if the horse is still alive.