Thanks Heleen. I think she's pretty cute myself.
Making circles is a common adaptive technique for blind animals. They'll do it to make sure they don't bump into things until they're 100% sure of an area. My guess is that if you put a leather collar and a smallish cowbell on the dam, that would go a long way to helping the foal orient herself in relation to her mom.
If she's broke to lead, you can also walk her around and let her explore fence lines and teach her how to deal with them by gently bumping her nose into the fence and saying, "Fence", over and over. I've done this will all my blind horses and they learn two things from it: 1. how to use their noses to bump and follow a fence line, and 2. they learn that when I say "FENCE" it translates to "Hey, you're about to run into something!". I can confidently turn Rose out in any enclosure, and know that she'll safely "map" an area before she goes running around AND I can shout "FENCE" from anywhere and she'll know that she needs to stop or turn immediately to avoid a collision with an object or another animal. You can also hang wind chimes in corners and near gates (where she can't eat them, of course) so she knows where they are, or install beepers like the kinds stores have (very cheap on Amazon), so that she can hear when she breaks the beam and the beep lets her know she's in the corner.
Desensitizing early, with anything and everything, is also a really good idea. Things will randomly, unexpectedly touch her all the time. Develop cues for anything and everything - be creative and patient. You'll be surprised how many words a horse can learn (recent studies say about 150 distinct words and phrases).
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