My sensitive skinned Maggie Moose also got doctor's orders to loose ~100 lbs this spring. Vet recommended the Green Guard grazing muzzle as it is supposed to be good for rub prevention. It is pricey, around $100, and as some folks here pointed out, it's basically just a big fruit basket you attach to your own halter https://www.greenguardequine.com/pro...grazing-muzzle
I think the general design is actually pretty good-it doesn't seem to interfere with breathing at all, and so far, no rubs for Maggie (I do have it on a fully padded halter). The one problem, with this or any muzzle, is that when the bugs are bad, they are pretty limited in biting at them.
Even though it fits well, she virtually refuses to even attempt to eat with it on, and just stands around pouting while wearing it. She has it on half the day, off half, and is turned out on so-so pasture 24/7. I have been struggling about whether it's really working for her though, as we are trading off the movement/exercise of grazing for standing still half the day resisting it. She can
eat with it on, I've seen her do it. She most definitely hates it though and pretty much doesn't move at all while she's wearing it.
This one from ThinLine looks similar but is cheaper. I wish I had seen it before I bought the one I bought. https://www.thinlineglobal.com/shop/...ow-feed-muzzle
PS- re: eating supplements, etc. Since it sounds like you are giving her some "hard feed" in a pan at least once a day, you can add loose table salt directly to that- I bought a one month subscription to the online program FeedXL (https://feedxl.com/
) to figure out how much I would need to feed, and when I entered all the details about hay, exercise, ration balancer, it suggested I feed 1tsp loose table salt twice/day. I just dump it on top of the pellets and swirl around with a tiny bit of water to moisten the pellets and get it to stick. They also get probiotics at that time. Muzzle comes off while she eats her pan and then back on. I haven't done any other kind of special supplements because she's getting a ration balancer in a quantity that should meet the majority of her needs.