Preventing calf scours, part 1 Dr. Sylvia Checkley | Back to Vet Advice
Calf scours (neonatal calf diarrhea) is a common problem in cow-calf herds. This is the most common infectious disease of baby calves. Neonatal calf diarrhea accounts for approximately a third of all death losses during the first month of life.
Neonatal calf diarrhea is caused by infectious agents that damage the calf's intestinal tract, causing diarrhea. The fluid loss then causes profound dehydration and often leads to death.
There are numerous agents that cause this diarrhea. Many cases of sick calves have more than one agent involved. These disease-causing agents include bacteria, viruses, and protozoa.
Table 1, below, is a summary of some of the more common causes.
Dietary causes of diarrhea are not as common as infectious causes. Milk scours is occasionally seen in calves that receive large volumes of very rich milk, or in calves that receive poor quality milk replacer. It is important that when you need to use a milk replacer that it is made from milk protein. It also must be mixed properly.
With diet-induced scours, calves develop a large volume of pasty manure. However, these calves remain bright, alert and have good appetites. This problem does not rapidly progress into severe dehydration and death as seen with the infectious causes of scours. Milk scours is usually seen in calves less than three weeks old.
Adult cows that shed organisms on and off with no outward signs of disease are major sources of disease-causing organisms. Shedding of organisms in adults often increases around times of stress such as calving time. Calves that are already scouring shed large numbers of organisms into the environment. Udders and bedding are contaminated with disease-causing organisms. The new calves then pick up organisms orally.
Clinical signs
Calf scours is a rapidly progressive disease leading from dehydration to death. Calves look fine and are suddenly found down. Affected calves show profound weakness and are unable to rise. They develop a diarrhea that varies from a pudding-like to a watery consistency in the more severe cases. The color of the diarrhea can be yellow, gray or brown. Occasionally blood is noted and this should be reported to your veterinarian.
Affected calves become severely dehydrated. The skin will stand up by itself for several seconds when tented above the eyes or on the side of the neck. Occasionally the animals will have a fever, but if outside during winter their temperature is very low due to hypothermia. Calves in earlier stages of the disease are still standing with wet tails, droopy ears, and are reluctant to move around. These calves are not nursing adequately.
Treatment
Severe outbreaks in given herds can cause pronounced losses of life and high costs of treatment in time and money. Fluid replacement is essential to correct dehydration and is the mainstay of treatment. Sick calves should be treated with oral electrolytes if they are still able to stand and nurse. They require electrolytes therapy because they will not be ingesting adequate fluids to maintain normal life functions and replenish fluids that are being lost in the diarrhea.
Electrolytes are sold as powder that is to be mixed with water. They are given orally by nipple bottle or stomach tube. These can be bought in individual packages or pails. These oral fluids are carefully formulated products that replace lost fluids, electrolytes and correct acidosis. Homemade recipes are not good substitutes for the good products we now have on the market. Electrolyte powders should not be mixed directly with milk.
However, milk is essential for energy and does not need to be withheld during electrolyte therapy with current electrolyte products. Milk should never be withheld more than 24 hours. This means you can alternate feedings of electrolytes and milk or the calf can nurse the cow between electrolyte feedings.
Calves that are down and unable to nurse are treated with intravenous fluids. By the time they are down, they are too severely affected to absorb fluids orally, making IV fluids necessary. The chance of regurgitation is higher when calves can’t support their head themselves after stomach tubing.
Calves are usually treated at the clinic for 24-48 hours. They are usually sent home when the manure is starting to firm up and they are able to nurse. These recovering calves will still require home nursing for a few days. Often calves are treated with antibiotics to combat infection, and/or anti-inflammatories to help reduce fever and discomfort.
Table 1. Causes of newborn calf diarrhea
| Type | Name | Calf age |
| Bacteria | E. coli | 1-4 days |
| (some strains 20-30 days) | ||
| Salmonella | 2-42 days | |
| Clostridia | 5-15 days | |
| Virus | Rotavirus | 5-15 days |
| Coronavirus | 5-21 days | |
| Protozoa | Cryptosporidium | 5-35 days |
| Coccidiosis | 30 days+ |
