I saw this on facebook and someone had mentioned that perhaps one of the mares gave birth to this colt a few years back and she just never noticed. I mean if they were receiving regular vet care this wouldn't have gone unnoticed. I'm not sure how she can prove it was dumped there.
Emaciated, feet unkept, I just don't understand people. It's probaby right, it was a colt out of one of her own mares, that no one noticed! Sad case, hopefully Humane society, or someone has stepped in!