225 ILCS 635/2.1

No carcass or part of a carcass of a horse, donkey, mule or other animal of the genus equus shall be transported into or slaughtered in the State of Illinois, or held, kept, sold, offered for sale or given away unless it shall be ground, chopped or comminuted so that no piece shall be greater than 3/4 of an inch in any dimension and unless the mass shall be denatured by thoroughly and evenly mixing therein ground bone in an amount sufficient to be felt and determined by feel when rolled between the fingers; or not less than 1% by weight of No. 10 to No. 14 U.S. standard mesh granular charcoal; or by coloring with a harmless coloring matter, other than red; or in any other manner approved by the Department of Agriculture of the State of Illinois. Nothing in this Act prohibits the sale or transportation of bulk meat to a licensed processor if it is denatured as provided above. This Act does not prohibit the sale or transportation of undenatured bulk horse meat to a licensed processor under a permit granted by the Director upon evidence satisfactory to the Director that such bulk horse meat will not be resold or again transported contrary to the provisions of this Act. Nothing in this Section shall apply to horse meat labeled as such in hermetically sealed containers and horse meat in frozen packages of one pound or less, clearly labeled "horse meat", bearing the federal inspection legend and packed in a federally inspected packing plant. (Source: P.A. 83-760.)