Section 520.602 - Dichlorvos gel(a)Specifications. Each milligram (mg) of gel contains 2.27 milligrams (mg) dichlorvos.(b)Sponsor. See No. 069043 in § 510.600(c) of this chapter.(c)Conditions of use in horses - (1)Amount. Administer 20 mg per kilogram of body weight for the removal of bots and ascarids. Repeat administration every 21 to 28 days for the control of bots and ascarids. For the control of bots only, the repeat dosage is 10 milligrams per kilogram of body weight every 21 to 28 days during bot fly season.(2)Indications for use. For the removal and control of first, second, and third instar bots (Gastrophilus intestinalis and G. nasalis), sexually mature and sexually immature (4th stage) ascarids (Parascaris equorum) in horses and foals.(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. 83 FR 48945 , Sept. 28, 2018