Just thought I should post this so you all can be aware of this very bizarre issue. My little stallion has been in and out of the animal clinic since January, couldn't keep weight on, did the wierd stretching thing etc. He was treated for impaction, and then for ulcers several rounds worth. He died suddenly a week ago, we took him to the university for an autopsy and the results were pretty awful. He had a stone that was 6 inches in diameter in his colon which eventually ruptured the colon and he bled out internally. The strange part is this, the vet said this starts with them ingesting a grain of sand, which lodges somewhere and grows. The biggest she'd ever heard of was 7 1/2 inches and that was in a warmblood, my little guy was only 30" tall! I do not live in a sandy region, but my show horses are on drylot, so I thought it might be good to start using sand clear or something on my show horses to try to prevent this from happening again. It is very sad around here these days, but if someone can take this and prevent heartache of their own at least it has done something.