Oxidative stress associated with nematode infections in sheep: a preliminary study

A hundred and seven sheep slaughtered at the Cold Storage Company (CSC) in Bulawayo, were examined for nematode parasite infections using coporological methods. Direct smear and salt floatation methods were used to observe nematode parasite eggs. Nine sheep were found to be infested with nematode eggs only. Nine uninfected sheep were used as controls. Liver samples collected from the infected and noninfected sheep were used for assays of the antioxidant enzymes, glutathione peroxidase (GPX) and diphosphotriphosho-diaphorase (DTD) as well as the intermediary metabolic enzyme,succinate dehydrogenase (SDH). Lipid peroxidation was assayed by determining malondialdehyde (MDA) levels. Significantly higher GPX activities were observed in infected sheep when compared with non- infected sheep (p < 001). No difference in the activity of DTD was observed in both infected and non-infected sheep (p>0.05). Parasitic infection resulted in significant reduction in SDH activity (p <0.05) and significantly higher MDA levels (p < 0.01). This study suggests that parasitic infections induce oxidative stress