Eighteen poisoned horses are being treated to spa days in their Florida stables, with their young riders brushing their manes and tails, painting their hooves and feeding them hay.

There's nothing else anyone can do for the doomed horses at Masterpiece Equestrian Center in Davie.

A batch of feed tainted by additives safe for other livestock but toxic to horses arrived at the center in September. All 22 horses there ate the feed for a month before anyone realized something was wrong.

Three horses died in October, and a fourth was euthanized Monday. The rest will die, some possibly as soon as this week.

The Lakeland-based company that sold the feed has recalled the product and acknowledged that the feed delivered to Masterpiece contained additives toxic to horses.

Florida's Department of Agriculture and Consumer Services is investigating.