There are a number of common diseases and disorders that affect cattle at various stages of life (Fig. 1). Cows may experience a difficult birth, and death losses at birth may be as high as 5%, though these losses can be overcome by selecting bulls known for the calving ease of their offspring. Diarrhea, caused by any of several species of bacteria, and pneumonia are the leading cause of death loss in calves. Calves may also be afflicted with less harmful disorders like pink eye. In older heifers, the primary risks include pneumonia, injury, and bloat. Cows may be afflicted by any of a number of disorders that result in a loss of milk production. Mastitis (inflammation of the udder), lameness, milk fever (hypocalcemia), ketosis, reproductive disorders, and bacterial diarrhea are some of the more common ones. Vaccination programs are effective at controlling or decreasing the severity of many of these diseases.