Nope he has never tied up. No idea what it was from he is in a program designed for him by a vet, he gets a blood panel, tpr and flexed by the barn vet every 2 weeks and we adjust the program accordingingly. He also has a nutritionist so I don't think the lactic acid was from any of those things specially since he wasn't any where near his peak in these past few weeks because we've been working him down so he could have june as a light month. We were working on a 7 day week, 1 gallop, 1 jump, 3 dressage, 2 hacks and 30 minute cool out walks every day that's never changed, I'm an eventer I take WAY to good care of my horse as do most eventers. His life is pretty much micro managed and since I see him all day every day because I'm a working student I know exactly whats happening and when changes are made I do it. Perks of being a working student you learn how to manage horses. I'm in charge of the daily care of 16 horses and believe me I could spout off the tpr, feed, worming, shoeing, immunization and work schedule of each horse right now. Sorry for ranting but being a pony clubber and barn manager I take offense when people hint at me being careless with my horses.