Section 520.2520c - Trichlorfon granules(a)Specifications. Each package contains either 18.2 or 36.4 g of trichlorfon.(b)Sponsor. See No. 054771 in § 510.600(c) of this chapter.(c)Conditions of use in horses -(1)Amount. 18.2 milligrams per pound of body weight.(2)Indications for use. For horses for removal of bots (Gastrophilus nasalis, Gastrophilus intestinalis), large roundworms (ascarids, Parascaris equorum), and pinworms (Oxyuris equi).(3)Limitations. Do not use in horses intended for human consumption. Federal law restricts this drug to use by or on the order of a licensed veterinarian.45 FR 48128, July 18, 1980. Redesignated and amended at 79 FR 28833, May 20, 2014