Veterinarian’s Corner: Dealing with Scours – Dr. Peter Strassburg, Lodi Veterinary Clinic

By Dr. Peter Strassburg, Lodi Veterinary Clinic
Calf diarrhea is a common and very frustrating problem when raising calves.  A calf with loose manure can become comatose in a matter of hours.  A newborn calf is 70 percent water, and it only takes a short time for it to become severely dehydrated.  Fluid losses from diarrhea are significant, and calves also lose essential electrolytes.  Electrolyte losses cause metabolic acidosis, and that makes calves more sick and lethargic.  Scouring calves need to have fluids replenished with an oral electrolyte solution that contains adequate sodium, potassium, chloride and a buffer to correct acidosis.  In addition, calves should be offered water 30 minutes after each milk feeding to ensure adequate hydration, especially in the summer months.

Scours is simply defined as diarrhea, but I categorize scouring calves into three categories: mild, moderate and severe.

• Mild cases:  Calves are bright, alert, and have a great appetite, but they still have slight diarrhea. These calves are otherwise healthy, but manure is looser than normal.
• Moderate cases:  Calves have watery diarrhea and are slightly depressed with an intermittent appetite.  They may or may not have a fever or blood in the feces.
• Severe cases:  These calves are down and out with profuse watery diarrhea. They will be lethargic, off feed and may not be able to stand.

With these three categories in mind, identifying scours early will help you decide on a treatment plan and increase your odds of treatment success.

Calves in the mild scours category should be monitored closely to quickly notice any change in attitude or appetite.  Offer these calves oral electrolytes at least once daily between milk feedings until the diarrhea improves.

Calves in the moderate category should be offered oral electrolytes at least two times daily between milk feedings until the diarrhea improves.  These calves may benefit from antibiotic therapy and/or a non-steroidal anti-inflammatory drug to help reduce fever and abdominal discomfort.

Calves in the severe category need to be assessed by your veterinarian.  These calves are in desperate need of IV fluid therapy with additional nutritional and electrolyte support.  With IV fluids, electrolyte support, and correcting the metabolic acidosis, these calves can improve in as little as 24 hours.

Antibiotic therapy is not indicated for every calf with scours, but it may be necessary for specific cases.  Antibiotics will not kill the organisms responsible for viral or some parasitic causes of diarrhea and should not be used.  The organisms that cause scours also damage the gut lining, which allows bacteria to enter the bloodstream (bacteremia) and causes a fever.  The damage to the gut lining causes bleeding and you may see evidence of blood in the feces.  These calves would benefit from an injectable broad-spectrum antibiotic to clear the bacteremia and a non-steroidal anti-inflammatory medication to reduce the secondary fever.  Using antibiotics for calves with scours is extra-label drug use and you will need to work with your herd veterinarian to develop a protocol for appropriate drug use.

These principles should help you diagnose and treat scouring calves sooner and more effectively.  If you have a large number of calves with scours, or they are not responding to treatment, get your veterinarian involved to help identify the causative agent and alter your treatments to better fit the needs of your animals.  Keep in mind that dry cow vaccination, high-quality colostrum and sanitation are all keys to reducing the incidence of scours.