Foundering is the same as laminates pretty much but if they founder it is usefully because they are too fat and there is to much toxins in them. it causes their gut to swell and not break food down properly and the toxins in the grass go to their hooves and turn them soft, pink/red and they pretty much fall apart from the inside out and the pain kills them. when they get to a bad stage you cant get the damage done to the hoves to be fixed and a lot of horses that founder are put to sleep before the pain kills them. also once a horse has got there before it is very and i mean very easy for them to get back there. it is more common in ponies as they tend to over eat more than horses. I have seen a pony be put to sleep because of it before. she only needed half an hour on grass to founder so was put down as being kept on dirt for the rest of her life was unfair and she was so sore. You thats my best explanation lol I not the best want any more ask a farrier they no it really well as they will see it a lot mine said he sees 3 cases a week and much worse then nugget a lot of them dying. Or look it up founder/laminates