HIGHLIGHTS
• Oxidative stress may play a role in ischemiareperfusion injuries seen in canine GDV.
• The benefit of antioxidant supplementation needs to be evaluated.

In this prospective study, biomarkers of oxidative stress and antioxidant status were determined in a group of 15 dogs with gastric dilatationvolvulus (GDV) over 48 hours. Normal homeostasis allows a balance between the production of reactive oxygen and nitrogen species and the production of endogenous antioxidants. Oxidative stress is part of the pathogenesis of many diseases, including ischemia-reperfusion injury, such as is seen with GDV. Previous studies have suggested that dogs with experimentally induced GDV benefited from the addition of antioxidants. This study evaluated dogs with naturally occurring GDV admitted for surgical correction. Measurements were taken at admission and 24 and 48 hours after admission. Assays of markers of oxidative stress included isoprostanes and malondialdehyde (MDA).Antioxidant status was evaluated by measuring vitamin C, vitamin E, glutathione peroxidase (GSHPx), and oxygen radical absorbance capacity. All of the measured antioxidants except GSHPx had significant decreases at the 24-hour postadmission sample. Median MDA levels decreased at 24 hours, but the isoprostane levels did not. Although this study was limited by size, timing of sample collection, and disease severity, the results indicate that the oxidative stress and antioxidant capacity with GDV change over time.

Serial determination of biomarkers of oxidative stress and antioxidant status in dogs with naturally occurring gastric dilatation-volvulus.Walker TG, Chan DL, Freeman LM, et al. J VET EMERG CRIT CARE 17:250-258, 2007.