That reminded me of my llama that I had. Not sure how well it relates to a horse, though. We were new to llamas, and once sheared, we noticed how thin one was. (They were VERY skiddish at first, so I wasn't able to touch or feel their body condition for a long time.) No matter what we did, he...
I like the camera idea. I'm by no means a horse expert, but not being able to be around him when this little girl is, would scare me. I'm not sure what she could do that wouldn't raise some suspicion in the blood work, but you never know. I also agree that you need to rule out what blueferral...