Sustain III calf boluses provide cattlemen with an effective antibiotic that lasts a full three days with just one treatment. Sustain III boluses quickly reach therapeutic blood levels within six hours after administration, provide higher peak blood levels of sulfamethazine and maintain therapeutic blood levels for a full three days. This one-two punch helps knock out diseases rapidly and surely. Sustain III calf boluses are intended for oral administration to ruminating replacement calves (calves over 1 month old that are not on an all-milk diet) and are indicated for the treatment of the following diseases when caused by one or more of the following pathogenic organisms sensitive to sulfamethazine bacterial pneumonia, colibacillosis and calf diphtheria.