Paraoxonase-1 activity evaluation as a diagnostic and prognostic marker in horses and foals.

Background: In several species, paraoxonase-1 (PON-1) decreases during inflammation, because of the presence of oxidative stress; its measurement recently has been validated in horses, but its role as a clinical biomarker is unknown.

Objectives: To evaluate sensitivity, specificity and likelihood ratio of PON-1 activity to identify systemic inflammatory response syndrome (SIRS)-positive horses or horses with a poor prognosis.

Animals: One hundred seventy-two blood samples from 58 sick horses from 3 different veterinary hospitals.