Section 520.1197 - Ivermectin sustained-release bolus(a)Specifications. Each sustained-release bolus contains 1.72 grams of ivermectin.(b)Sponsor. See No. 000010 in § 510.600(c) of this chapter.(c)Related tolerances. See § 556.344 of this chapter.(d)Conditions of use in ruminating calves -(1)Amount. Administer one bolus per calf weighing at least 275 pounds (lb) (125 kilograms (kg)) and not more than 660 lb (300 kg) on the day of administration.(2)Indications. For treatment and control, throughout the grazing season (approximately 130 days), of gastrointestinal roundworms Haemonchus placei, Ostertagia ostertagi (including inhibited fourth-stage larvae), Trichostrongylus axei, T. colubriformis, Cooperia spp., Nematodirus helvetianus, Bunostomum phlebotomum, Oesophagostomum radiatum; lungworms Dictyocaulus viviparus; grubs Hypoderma spp.; sucking lice Linognathus vituli, Solenopotes capillatus; mange mites Psoroptes ovis, Sarcoptes scabiei, and ticks Amblyomma americanum.(3)Limitations. The bolus was specifically designed for use in cattle; do not use in other animal species. Calves must be ruminating and older than 12 weeks of age. Do not administer to calves weighing less than 275 lb (125 kg). Do not administer a damaged bolus. Because a milk withdrawal time has not been established, do not use in female dairy cattle of breeding age. Do not slaughter cattle within 180 days of treatment. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism.61 FR 67452, Dec. 23, 1996, as amended at 62 FR 63270, Nov. 28, 1997; 65 FR 45876, July 26, 2000; 84 FR 39183, Aug. 9, 2019