I picked it up working for a guy that grew up in Elmont, so he spent a lot of time at Belmont Park -- his father owned a couple of TB. TB trainers were, I don't know if they still are, big on jugging horses -- pre and post race, electrolytes, vitamins, and yes sodium iodine. Just a quick way of replenishing whatever a horse might have lost racing and/or training. On another note I always fed my horses a little calf manna -- really brought out the shine in their coats. Then once at Hollywood Park a handful of trainers (me included) got a $200 positive for something (I can't remember what it was) that was in the calf manna. It took us about a week to figure out we were all using calf manna and that's where the (substance) positive came from. Needless to say we stopped with the calf manna.