The Contribution of Specific and Nonspecific Biomarkers in Diagnosis of Equine Gastric Ulcer Syndrome (EGUS) Under Field Condition

The aim of this study is to investigate the diagnostic efficiency of gastrin, pepsinogen, proinflammatory cytokines (TNF-α, IL-6), and oxidative stress biomarkers in horses with equine gastric ulcer syndrome (EGUS). Thirty horses diagnosed with gastroscopic EGUS and 15 clinically healthy horses were selected for this study. The serum levels of gastrin, pepsinogen showed nonsignificant changes in horses with EGUS when compared with healthy horses. The serum levels of TNF-α, IL-6 revealed a significant increase in horses with EGUS when compared with healthy ones. Oxidative stress is evident in horses with EGUS in comparison with healthy horses as detected by higher levels of malondialdehyde (MDA) and decreased serum levels of total antioxidant capacity (TAC), Superoxide dismutase (SOD), glutathione (GSH), and nitric oxide (NO). MDA and TNF-α showed better sensitivity and specificity than IL-6 in distinguishing horses with EGUS from control horses. Conclusively, examination of serum gastrin and pepsinogen levels had a limited value in diagnosis of EGUS in horses under investigation. Moreover, this study showed that oxidative stress is evident in horses with EGUS. Higher levels of TNF-α and IL-6 indicate their role in EGUS pathogenesis in horses. Finally, MDA, TNF-α, and IL-6 could be used as biological markers for preliminary screening of horses with EGUS. Gastroscopy still accredited as the "gold standard" for diagnosis EGUS.