Livestock: January 2004

Calf scours is one of the most frustrating experiences in a cow calf operation. Actually, "scours" is just the symptom of a disease that can be caused by many different bacteria and viruses. Adverse environmental factors can also contribute to an outbreak — cold, wet and muddy conditions are the most common culprits. It is also one of the most costly diseases. Mortality can be more than 50 percent in severe outbreaks, and morbidity can be even higher, resulting in astronomical treatment costs. As with all diseases, prevention should be the primary focus.

The first phase of prevention involves the cow or heifer 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 the colostrum she passes on to her calf at birth. If scours is a recurring problem in your herd, your veterinarian may recommend vaccination of the 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, which in turn maximizes colostrum quality. Shorting a pregnant cow nutritionally pre-calving increases the chances her calf will get sick or die. Cows should be in a body condition score of 5.5-6.0 and on a positive plane of nutrition at calving.
   
• Minimize calving difficulty through adequate heifer development, and female and bull selection. This may sound like a far-fetched means of scours prevention, but dystocia reduces vigor of both cow and calf and slows the time between birth and the calf's first nursing.
   
• Plan to calve in the driest, most protected area possible, to reduce stress of both the dam and her newborn. Calves can stand a lot of cold if they are dry and out of the wind. More space is preferable to less, mainly because the disease is so highly contagious. The smaller the calving area, the easier it is to spread.
   
• Consider moving the pairs to a different pasture periodically as they calve during the calving season.
   
• Calve heifers as a separate group since 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.
   
• Scours organisms are highly contagious and spread rapidly through contact and even inhalation. Isolate affected calves immediately and do not expose healthy calves.
   
• Your veterinarian may also recommend sampling the stool of a sick calf to culture and identify the causative organism.
   
• Dehydration is usually the most immediate concern with scours. Your veterinarian will surely outline a fluid therapy to be used. All products and tools should be on hand well in advance of the calving season.

Calf scours can be caused by many different organisms and made worse by adverse environmental conditions. A prevention program is the first line of defense. Still, you should be prepared for an outbreak every year, developing a program with your veterinarian focusing on detection, isolation, diagnosis and treatment.