Description Sustain III Calf Boluses (sulfamethazine) are intended for oral administration to ruminating replacement calves older than 1 month that are not on an all-milk diet. Indicated for the treatment of the following diseases when caused by one or more of the following pathogenic organisms sensitive to sulfamethazine: Bacterial pneumonia (Pasteurella spp.) Colibacillosis (bacterial scours) (E. coli) Calf diphtheria (Fusobacterium necrophorum) Each bolus contains sulfamethazine (formulated in a sustained-release base) 123.8 grains (8.02 grams). Provide 1 bolus per 50 pounds of body weight. Do not use in calves younger than 1 month, calves being fed an all-milk diet, or female dairy cattle 20 months and older. Meat withdrawal: 12 days.