A couple of days, she foundered anyway. I called the vet and he told me that miniature horses were prone to foundering. Turns out our pastures are just too rich for her and she's gorging herself on all kinds of goodies. He told me to put her in a stall and give her only hay, which I did. She got better right away, but she absolutely hated being in the barn by herself. I only left her in there about two days, then moved her out to the pasture that had been grazed down the most.
She was fine for a while, but after a couple of weeks, I could tell her feet were getting sore again. So, back into the barn she went.
This picture isn't out of focus, but it looks like it is because Pony has paced round and round stirring up dust. The dust has caused a deep cough.
"Let me out!"
After about four days in exhile, she was much, much better. I put her out in the round pen for about an hour on the second day, then a couple of hours the next day, then I had Tom mow the pasture as short as possible. Back outside she went. Mustn't have her coughing. She was running around kicking up her heels and tossing her head, so happy to be back outside.
If keeping the pasture trimmed short doesn't keep her from foundering, I don't know what we're going to do to get through spring and all the new growth. I read up on miniature horse websites and they recommend not letting them graze until about July when the grass isn't as rich. I really can't imagine how we could manage that. I just can't keep her in the barn. The only thing I can think of to do is to make a smaller pen within the pasture to keep her in and let it go just about bare.
Oh, and she lost all that extra weight she was carrying around. Looks much better.