Adverse environmental factors can also contribute to an outbreak. Cold, wet, muddy conditions are the most common culprits.

Preventing calf scours, which is the best course, is a two-phase operation, says Noble Foundation livestock specialist Clay Wright. The first phase involves the dam and the environment.

  • Develop and implement an overall herd-health program with your veterinarian and review it at least annually. The cow's own immune status directly affects the quality of her colostrum. If scours is a recurring herd problem, your veterinarian may recommend vaccinating dams against the most common scour-causing organisms prior to the calving season.

  • Good nutrition and adequate body condition help maintain the dam's immunity level and maximize colostrum quality. Shorting a pregnant cow nutritionally pre-calving increases her calf's chances of illness and death. Cows should be in a body condition score of 5 ½ to 6 and on a positive plane of nutrition at calving.

  • Minimize calving difficulty through adequate heifer development, and female and bull selection. Dystocia reduces vigor of both cow and calf and slows the time to a calf's first nursing.

  • Plan to calve in the driest, most protected area possible to reduce stress on the dam and newborn. Calves can withstand cold if they're dry and out of the wind. Larger calving areas are preferable as the disease is so highly contagious.

  • Consider moving pairs to a different pasture periodically as they calve during the calving season.

  • Calve heifers as a separate group. Their calves' immunity levels are generally lower than those of mature cows.

  • The second phase of prevention is at calving, when and if an outbreak occurs.

  • Pre-plan a course of action with your veterinarian and implement it immediately when the first case occurs.

  • Isolate affected calves immediately and do not expose healthy calves.

  • Your veterinarian may recommend stool sampling of sick calves to culture and identify the causative organism.

  • Dehydration is usually the most immediate concern with scours. Have your veterinarian outline a fluid therapy to be used, and keep all products and tools on hand well in advance of the calving season.
"You should be prepared for an outbreak every year, developing a program with your veterinarian that focuses on detection, isolation, diagnosis and treatment," Wright says.