I would say put your mare in your name and then ask your dad if you can move her to this barn. If he says no, you would have legal rights to move her. It would royally piss him off but you need to get away from him as much as possible!
I only have her APHA papers. I have her coggins...but its expiring. All the recent vet bills from the point forward will be put in his name. And I don't know about the rest of horse owners on the website...but where I'm from everyone uses the coggins as proof of ownership.
What scares me the most is there is an auction, near where I live. Called the SugarCreek Horse Auction, and 97% of the horses there are taken to Mexico or Canada...for slaughter. The owner of the auction buys 97% of the horses going through the auction...and ships them off to the slaughter houses.
Now...I've went on craigslist and have watched horses, in this very rich and equestrian community/area that I live in...stay on craiglist for months and months. There's a halflinger pony...completly sound, UTD on everything, childrens hunter priced at a resonable $1,500 stay up for sale from August until now. And is still for sale.
Imagine what would happen to a mare that can't be ridden, that can only walk and is only sound for very, very light riding. I'm absolutly terrified. She's THE sweetest, friendliest mare...never hurt a fly, and she DESERVES to be alive, to be healthy, to be happy. She keeps her rider safe, and is mindful of little kids...has perfect manners and tolerates just about anything. I've thrown tarps, bouncing balls, umbrellas on her back....the neighbors dogs used to nip at her heels, beginners yanking on her mouth because they don't know any better yet, cried for hours into her mane....and yet, she stands there, calm....patient, waiting, harmless...she'd go through anything for her rider.
And on top of it...everyday I have to go to work. A small Vetrinarian Clinicf where everyone knows everyone. And almost every day...people come in, recongize me and know that I'm the "girl with the horses down the street" and ask...how's your mare? Have you been riding? How are the horses doing" and I have to choke back tears and say...there fine, there doing great. Constant reminders of the fear and the pain. And I just don't know how to get her out of there. I'm sure he'd do something stupid...like make me pay the price he paid for her. $2,000 which I don't have.