Just an FYI, many underweight malnourished horses are very calm and docile. You get em home and get em fattened up and the true personality comes out. So you cant really say. Seeing a horse like that really makes me sad. None of us wants to be stuck with medical problems but Its real hard to walk away from a horse in need,
My Walker is a work in progress , the lady that sold him was in dire finacial straights and had him in a small yard with no grass, he was underweight. She was doing the right thing and trying to find him a home. He had been handled very rough some where and had been riden in a big square skirt saddle that hurt him. He was afraid of everything, terrified of western hats, didnt know what lunging was, feet needed help. Was definetly not the horse for me,,,,,, and I couldnt bare to leave him behind, I opened my trailer and he ran inside. We still have some spook issues to work through and it has been a long rode, but he gets better every day I am with him.
I had a great horse before with too much go, I gave up on and sold and have regretted it ever sense. I should have spent the money on a trainer.
Currently you have two known evils, You want to sell and buy an unknown evil. I'd take the known any day. Keep your horses. Spend some money on some DVD's, Julie Goodnoght Lead line basics, Gary Lane, who specializes in gaited horses.Perrili DVDs. Dont try to do it all just do one different task a few times a week. The Spooky ness will subside with the right training and drills.
Once you get stand, send out left, send out right and back up, start working on the OOGY WOOGY drill, Back the horse up and a lead line, then run up to it sliding your hand along the lead line,waving your arms , yelling OOGY WOOGY WOOGY, when you get close give it the STAND command, as soon as its feet stop, you stop, do the same for the left and right side a few times. Next time do it wih a plastic bag,, or a cowboy hat,( mine was beat in the face with one so was terrified of them) Or a beer can with rocks in it. Again what ever type of stuff they are spooky with. My horse has gotten to the point he just stands there and looks in my pocket for horse treats when I do it, Generally he'll just raise his head a bit at first.
My horse would spook at strange things on the trail when I got him, He would jump straight up, spin around back at high speed, rear on his hind legs, etc etc, I havent taken all the spook out of him but what I have taught him to do is "Freeze" when he is spooked at something, Way more easier and safer to deal with on the trail.
Guess my point is, you can spend a couple grand on a well trained horse that may be a mistery or spend a bit of time and the same money working with yours. A 3 day training siminar with Gary Lane will teach you tons of stuff. For less money than buying a new horse/