A Florida equestrian center where 22 horses were poisoned by tainted feed has reached a settlement with Lakeland Animal Nutrition, the company that produced and sold the feed.

Although the terms of the settlement with Lakeland Animal Nutrition are confidential, it is reported that all of the owners of the horses will be able to buy new horses and care for the remaining ailing horses — all of which are expected to die. The afflicted horses range from ponies worth $25,000 to $50,000 to elite competitors worth hundreds of thousands of dollars.

The feed arrived at the center in September, but it was weeks before anyone realized something was wrong with the horses. It wasn’t until three horses at the farm developed sudden paralysis and collapsed in October that they knew something was wrong; within a week all three horses died.

Days later, testing of the feed, conducted at the horse owners’ request, came back positive for monensin, an anti-bacterial additives safe for livestock such as cattle and some poultry, but deadly to horses.

Monensin (Rumensin—Elanco) is produced as an additive for feeds for ruminants. The problem, however, is that horses are extremely sensitive to monensin poisoning.

After learning of the test results, Lakeland Animal Nutrition recalled the contaminated horse feed products. The company claims the contamination was limited to the feed at the equestrian center, and that no other horses have been reported to have been sickened because of it.

Since the first deaths in October, three more horses had to be euthanized, bringing the death toll at the farm to six since October.

Necropsies performed on four horses that died at the farm before the settlement last week confirmed monensin poisoning.

All the horses at the center ate the contaminated feed, and all are expected to eventually die. The remaining horses all are showing progressive symptoms of monensin poisoning, including difficulty standing. Treatment of monensin poisoning is primarily supportive – there is no antidote.

Their owners can do little except keep vigil over the animals as their health fails. While they wait, they try to keep their horses comfortable, give them extra treats, grooming them, and lavishing them with love and attention.