CALF-GUARD 25 INDIVIDUAL DOSES - ZOETIS - Rotavirus - Coronavirus vaccine. For the vaccination of healthy newborn calves and pregnant cows against diarrhea (scours) caused by bovine rotavirus and bovine coronavirus. The dosage for both cows and calves is 3 ml. Administer to cows intra-muscularly (IM) and to calves by mouth. Vaccination of calves older than one day of age may not be effective. See label for further details. CAUTION: 21 Day slaughter withdrawal.