Evaluation of Trace Elements, Oxidant, and Antioxidant Status in Polo and Dressage Horses with or without Lameness

Horses are used for sports such as polo or dressage are prone to exercise-induced oxidative stress, due to increased energy demands during exercise. There are no reports of levels of Reactive oxygen species (ROS ) formation, antioxidant response, and trace minerals’ profile variations between polo and dressage horses, particularly in conjunction with the occurrence of lameness. This study, therefore, compared the serum concentrations of trace elements (TE) and oxidants/antioxidants between polo and dressage horses. Forty healthy horses, comprising polo (33) and dressage (7) were sampled. The polo horses were made up of 21 females and 12 males, while the dressage horses were made up of 2 females and 5 males. Blood (5mls) was collected from the jugular vein into plain bottles for the determination of serum concentrations of selected oxidants and antioxidants, ascorbic acid, Manganese, Copper, Zinc and Magnesium using spectrophotometric and colorimetric techniques. Means of the oxidants and antioxidants were compared between groups using an independent T-test. Correlation between the oxidants, antioxidants and trace elements was determined using Pearson correlation coefficients. Results were considered significant at P ≤ 0.05. Serum malondialdehyde (MDA) concentration was higher ((P < 0.05)) in polo (2.21 ± 1.05 U/L) than dressage horses (1.71 ± 0.48 U/L). Similarly, serum MDA and GPX concentrations were higher (P < 0.05) in males (2.58 ± 1.08 U/L; 25.30 ± 6.52 U/L) than in female horses (1.93 ± 0.90 U/L; 16.2 ± 4.80 U/L). However, concentrations of MDA were significantly (P < 0.05) lower in shod (1.63 ± 0.74 U/L) than in unshod horses (1.63 ± 0.74 U/L). Also, serum magnesium was significantly (P < 0.05) lower in polo (2.67 ± 0.88 mg/dl) than in dressage horses (3.717 ± 1.97 mg/dl). It can be concluded that the use, sex, and shoeing status of horses affect concentrations of MDA and antioxidants. This could have implications for the precipitation of degenerative or metabolic diseases related to oxidative stress in predisposed horses.