Neonatal Calf Diarrhea (Scours)
Calf scours are defined as loose manure that persists for two or more days and can be accompanied by a decrease in appetite, lethargy, dehydration, and fever. Seventy-five percent of dairy calf losses in the first year of age occur within the first month of life, with 56.5 percent of those occurring due to scours. Many steps can be taken to reduce the incidence of scours, including vaccinating dams, feeding adequate high-quality colostrum, reducing nose-to-nose contact, and following proper sanitation practices between calves.
Potential Causes
- Nutritional: changing brands of milk replacer, changing from waste milk to milk replacer, or increasing feeding volumes
- Pathogenic: bacteria or viruses such as rotavirus, coronavirus, E. coli, Salmonella, Cryptosporidium, and many others
Clinical Signs
- Watery stools
- Sunken eyes
- Skin tenting
- Lethargy/depression
- Dry mucous membranes
- Cool extremities
- Poor pulse
- White/dry gums
Assessing calf manure can be accomplished using the fecal scoring system shown in the photos below. You can determine the amount of oral rehydration necessary for survival using the dehydration status of a calf (see table below). To estimate how much to feed a calf, multiply the weight of the calf by (dehydration percent ÷ 100). This will give you the pounds the calf needs to drink in addition to its milk or milk replacer feeding. Then divide by 2 to get quarts of liquid needed.
| Dehydration Status | Symptoms |
|---|---|
| 5–6% | Diarrhea, no clinical signs, strong suckling reflex |
| 6–8% | Mild depression, skin tenting 2–6 seconds, calf still suckling, sunken eyes, weak |
| 8–10% | Calf depressed, lying down, eyes very sunken, dry gums, skin tenting > 6 seconds |
| 10–14% | Calf will not stand, cool extremities, skin won’t flatten when tented, comatose |
| Over 14% | Death |
Adapted from Naylor, J. M. 1989. "A Retrospective Study of the Relationship between Clinical Signs and Severity of Acidosis in Diarrheic Calves." Canadian Veterinary Journal 30 (7): 577–80.
Example
A 100-pound calf is dehydrated 6 percent. 100 × 0.06 = 6 pounds. 6 pounds ÷ 2 = 3 quarts need to be fed per day in addition to her usual milk (which would be 5 quarts if the calf is fed at 10 percent of body weight). The total amount of fluids the calf needs (milk plus the rehydration solution) is 8 quarts per day.
Prepared by Dr. Hayley Springer, extension veterinarian, and Cassie Yost, extension dairy educator.
This fact sheet, including its text, graphics, and images ("Content"), is for educational purposes only; it is not intended to be a substitute for veterinary medical advice, diagnosis, or treatment. Always seek the advice of a licensed doctor of veterinary medicine or other licensed or certified veterinary medical professional with any questions you may have regarding a veterinary medical condition or symptom.
