Making a treatment decision for a horse in the throes of colic can be difficult. Will surgery save his life or simply prolong his pain?

To help clinicians make more accurate prognoses— and, specifically, identify horses most likely to survive—researchers at Iowa State University and North Carolina State University have devised a colic-survival scoring system.

To construct the system, researchers first collected data from medical records of 67 horses seen at Iowa State University veterinary clinic for acute abdominal pain.

In each record, 28 key variables were identified and assessed. Of those, the researchers found that six variables were highly correlated with survival: heart rate, respiratory rate, total serum calcium concentration, blood lactate concentration, abnormal ultrasound and abnormal rectal findings. These variables then served as the basis of the colic assessment score (CAS).

For the second phase of the study, the researchers utilized the CAS to assess 95 horses over the course of one year. Horses were given scores of 0, 1 or 2 for each variable, making the lowest possible score 0 and the highest possible 12. A score lower than 7 suggested that a horse was more likely to survive, while a score of 7 or higher pointed to a lower probability of recovery.

When these predictions were compared to the actual outcomes, the researchers found the CAS had positive predictive value of 88 percent, meaning that 88 percent of the horses who were expected to survive did.

Reference: “Development of a colic scoring system to predict outcome in horses,” Frontiers in Veterinary Science, October 2021