PON1 and systemic inflammatory response syndrome: Conversely, in mares, PON‐1 activity was significantly lower (P = .05) in SIRS‐positive horses (44.8 ± 11.2 U/mL; 45.8 U/mL; 35.4‐54.5 U/mL; n = 27) compared with SIRS‐negative horses (53.9 ± 9.1 U/mL; 54.6 U/mL; 48.9‐56.9 U/mL; n = 9).