Synulox Bolus 500 mg film-coated tablet Dosage and administration Administration By the oral route. Dosage rate 6.25–12.5 mg/kg bodyweight twice daily, e.g. a 40 kg calf will require ½ bolus twice daily, but this may be doubled in cases of severe infection. Treatment should be continued for up to 12 hours after the clinical signs have subsided to a maximum of 3 days of treatment.