Section 520.1326b - Mebendazole and trichlorfon paste(a)Specifications. Each gram of paste contains 100 milligrams of mebendazole and 454 milligrams of trichlorfon.(b)Sponsor. See No. 000061 in § 510.600(c) of this chapter.(c)Conditions of use in horses - (1)Amount. 8.8 milligrams of mebendazole and 40 milligrams of trichlorfon per kilogram of body weight.(2)Indications for use. It is used in horses for treatment of infections of bots (Gastrophilus intestinalis and G. nasalis), large roundworms (Parascaris equorum), large strongyles (Strongylus edentatus, S. equinus, S. vulgaris), small strongyles, and pinworms (Oxyuris equi).(3)Limitations. Do not administer more than once every 30 days. Do not treat sick or debilitated animals, foals under 4 months of age, or mares in the last month of pregnancy. Trichlorfon is a cholinesterase inhibitor. Do not administer simultaneously or within a few days before or after treatment with, or exposure to, cholinesterase-inhibiting drugs, pesticides, or chemicals. Do not administer intravenous anesthetics, especially muscle relaxants, concurrently. Not for use in horses intended for food. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism.51 FR 13212, Apr. 18, 1986, as amended at 62 FR 61625, Nov. 19, 1997; 78 FR 28824 , May 20, 2014