I'm going to be gone on vacation for about a week, my horse only eats grass, so if she's not excersised all week and is grazing all day will she be overweight when I come back?

I don't think they will be overweight from grass, as horses do naturally take periodical breaks from eating and grass is not high in calories.
Depends on how much grass she is turned out on and how much you normal ride him. If you ride about three times a week he shouldn't be to overweight by the time you get
Oh ok
I would put a grazing muzzle on so that they get grass not so much they could founder or become over weight that is what I would do myself
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