Lechuza also issued a statement to AP acknowledging that a Florida veterinarian wrote the prescription for the pharmacy to create a compound similar to Biodyl, a French-made supplement that includes vitamins and minerals. Biodyl is not approved for use in the United States.

"Only horses treated with the compound became sick and died within 3 hours of treatment," Lechuza said in the statement. "Other horses that were not treated remain healthy and normal."

Lechuza also said it was cooperating with authorities that include the State Department of Agriculture and Consumer Services and the Palm Beach County Sheriff's Office.

This is so sad.