Zerofen 10% Dosage and administration Assess bodyweight as accurately as possible before calculating the dosage. Shake container before use. Cattle Give as an oral drench at the rate of 7.5 mg fenbendazole per kg bodyweight (approximately 1 ml per 13 kg bodyweight). Cattle Bodyweight Dose  65 kg  5 ml 130 kg 10 ml 200 kg 15 ml 265 kg 20 ml 335 kg 25 ml 400 kg 30 ml Over 400 kg give 5 ml per 65 kg.   Sheep Give as an oral drench at the rate of 5 mg fenbendazole per kg bodyweight (approximately 1 ml per 20 kg bodyweight). Sheep Bodyweight Dose Up to 10 kg 0.5 ml 11–20 kg 1.0 ml 21–30 kg 1.5 ml 31–40 kg 2.0 ml 41–50 kg 2.5 ml 51–60 kg 3.0 ml 61–70 kg 3.5 ml 71–80 kg 4.0 ml Over 80 kg give 0.5 ml per 10 kg.