Code of Federal Regulations Title 21. Food and Drugs § 21.520.905e Fenbendazole blocks

(1) Each pound of molasses block contains 750 milligrams of fenbendazole.

(2) Each pound of protein block contains 750 milligrams of fenbendazole.

(1) Amount. 0.1 pound of block per 100 pounds of body weight per day for 3 days. Total dose for the 3–day period is 2.27 milligrams of fenbendazole per pound of body weight for mature cattle.

(2) Indications for use. For removal and control of infections of lungworms (Dictyocaulus viviparus) and gastrointestinal roundworms (Haemonchus contortus, Ostertagia ostertagi, Trichostrongylus axei, Bunostomum phlebotomum, Nematodirus helvetianus, Cooperia oncophora and C. punctata, Trichostrongylus colubriformis, and Oesophagostomum radiatum) in beef cattle.

(3) Limitations. Administer free choice of beef cattle on pasture that have become accustomed to nonmedicated block feeding during an adaptation period of 12 to 19 days. Molasses block:  Cattle must not be slaughtered within 11 days following last treatment. Protein block:  Cattle must not be slaughtered within 16 days following last treatment;  do not use in dairy cattle of breeding age. Animals maintained under conditions of constant worm exposure may require retreatment within 6 to 8 weeks. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism.