Because of their size and age, young calves, just like young children, tend to be primed for infection and can be easily overtaken by disease. That’s why it’s critical that this group of animals is carefully monitored and managed to identify disease early.

In a retrospective study, researchers from Ludwig Maximilian University of Munich, Bavarian Animal Health Service, and the University of Illinois collaborated to identify what indicators of calf illness were most closely tied with fatalities. They looked at 1,400 critically ill calves suffering from diarrhea and found that clinical observations rather than lab measurements were better predictors of mortality.

Of the 1,400 calves under the age of 21 days of life, 22 percent either died or were euthanized. Among that group, neurological disease, gastrointestinal problems, cachexia (weight and muscle loss), and orthopedic problems such as septic arthritis (joint infections) were the best indicators of calf death.

All of those clinical observations ranked above the first laboratory indicator — profound acidemia or low blood pH. One of the researchers, the University of Illinois’ Peter Constable, said, “It appears that blood pH is a biomarker of the severity of other abnormalities, such as organ dysfunction.”

A normal blood pH runs around 7.4, but for 54 percent of the calves in the study, blood pH fell below 7.2, which is described as severe acidemia. A blood pH below 6.85 was considered profoundly acidemia and a predictor of mortality.

“Our findings strongly suggest that prognosis in critically ill calves with diarrhea can be made more accurate by considering both clinical signs and laboratory values, and support the adage ‘treat the patient and not the laboratory value,’” shared the group in their article in Plos One.