Evaluation of plasma catecholamine and serum cortisol concentrations in horses with colic.

This study explores the association of cortisol and epinephrine concentrations in horses with colic, relating these hormone levels to clinical symptoms, standard lab results, and survival outcomes in the animals.

Study Methodology

• The research was a prospective observational study involving 35 horses referred to a veterinary hospital due to colic.
• Blood samples were collected from the horses within 30 minutes of their arrival at the hospital.
• These samples were analyzed for cortisol, epinephrine, norepinephrine, lactate, and electrolyte concentrations, and for acid-base variables.
• The heart rate of the horses upon their admission to the hospital was also recorded, as was the outcome of their treatment (either survival or nonsurvival).
• Univariate logistic regression was used to calculate crude (unadjusted) odds ratios and 95% confidence intervals.

Study Findings

• Out of the 35 horses with colic included in the study, 26 survived their condition.
• Horses with higher plasma levels of epinephrine, serum levels of cortisol, and plasma lactate concentrations had an increased risk of nonsurvival compared to horses with lower levels of these substances.
• Plasma norepinephrine concentration was not found to be associated with survival outcome, unlike the other two hormones.
• Plasma epinephrine concentration was significantly correlated with heart rate, plasma lactate concentration, blood pH, anion gap, and base excess—variables which often serve as indicators of health severity in horses with colic.

Conclusion

• High circulating concentrations of epinephrine and cortisol appear to increase the risk of death in horses with colic.
• The significant correlation of plasma epinephrine concentration with heart rate and certain biochemical markers supports the notion that, in horses with colic, the severity of the illness can be inferred from routinely measured variables.