# Evaluation of oxidative stress and antioxidant defense biomarkers in healthy and colic horses: correlation with type of colic and outcome

## TL;DR

This study examines oxidative stress and antioxidant biomarkers in horses with colic, finding that certain markers may help predict survival and distinguish between types of colic.

## Contribution

The study identifies specific oxidative stress biomarkers, like AREase, that correlate with survival and colic type in horses.

## Key findings

- Colic-affected horses showed higher AREase, GST, and GPx compared to healthy horses.
- Survival was associated with higher AREase and lower SOD and TAC levels.
- Non-strangulating colic was linked to lower LPO and higher SOD and TAC compared to strangulating colic.

## Abstract

Colic is a major cause of morbidity and mortality in horses, with oxidative stress implicated in its pathophysiology.

Evaluate biomarkers (BIOs) of oxidative stress and antioxidant defense in healthy horses and those with non-strangulating colic (NSC) and strangulating colic (SC) and assess correlations with survival.

Seventy-one adult horses: 10 healthy and 61 colic-affected (42 NSC, 19 SC) admitted to 3 veterinary teaching hospitals.

Prospective, multicenter cohort study. Blood samples were collected at admission (T0) and up to 96 h post-admission. Biomarkers measured included arylesterase (AREase), paraoxonase (POase), lipid peroxidation (LPO), superoxide dismutase (SOD), butyrylcholinesterase, total antioxidant capacity (TAC), glutathione S-transferase (GST), and glutathione peroxidase (GPx). Data were analyzed using nonparametric statistics and generalized linear mixed models.

Compared with healthy horses, colic-affected horses had higher AREase (P = .01), GST (P = .001), and GPx (P = .001), and lower POase (P < .001) and TAC (P = .02). Survival was associated with higher AREase (coefficient [coef.] 106.65 kU/L; 95% confidence interval [CI], 24.70-188.60; P = .01), lower SOD (coef. −0.38 U/mL; 95%CI, −0.76 to −0.06; P = .03), and lower TAC (coef. −3.37 μmol/mL; 95%CI, −5.49 to −1.25; P = .01). Colic type also influenced results, with NSC (vs SC) associated with lower LPO (coef. −1.24 malondialdehyde [MDA]/μL; 95%CI, −2.81 to −0.32; P = .01), higher SOD (coef. 0.42; 95%CI, 0.03-0.81; P = .04), and higher TAC (coef. 1.21; 95%CI, 0.10-2.98; P = .04).

Results emphasize the association between oxidative stress BIOs and colic in horses, suggesting that specific BIOs, particularly AREase, may have prognostic utility.