Oxidative-stress induced changes in correlation with seroconversion in EIA seropositive horses.

Summary The objective of the present experiment was to verify the hypothesis that oxidative stress characteristic changes are correlated with the presence of the equine infectious anemia virus (EIAV) in infected horses. The research was based on the results obtained at the agar gel immunodiffusion test (Coggins test), which represents the prescribed test for international trade at the present time (OIE). From the investigated horses (n=23) blood samples were collected in order to quantify the activity of the main antioxidant enzymes – superoxid+dismutase (SOD), cathalase and the genera l peroxidaze activity + in parallel with the lipidic oxidative level, the concentration of the total blood lipids and uric acid. Results were statistically analyzed using the “r test” (estimation of the correlation quotient) giving scores for the positivity regarding the agar gel immunodiffusion test + Coggins (value 1) respectively for the negativity (value 0). The obtained results show that the enzymatic activity of superoxid+dismutase (SOD) and the gener al peroxidaze activity markedly decrease in the EIAV infected horses compared to the healthy ones, while the cathalase activity decreases moderately in these animals. The cathalase activity in the healthy horses is positively correlated with the Coggins test results, with a level of signification smaller then 0.01, while the other enzymes do not have statistically representative changes. The level of lipid peroxidation in the infected horses is the only indicator of oxidative stress which has a positive correlation with the presence of EIAV (highly significant increase – 0.001horses can confirm his antioxidant role in vivo in horses. In the present, the horse still has an important role in Romania, both in the small private farms, as well as an animal for leisure and sport. Equine infectious anemia can be considered as the most important and difficult to control infectious disease of the horse, because of the high percentages of morbidity and mortality. Equine infectious anemia virus (EIAV), a member of the genus Lentivirus of the family Retroviridae, affects all members of the family Equidae and is distributed worldwide (Issel and Coggins, 1979; Cook et al., 2001). EIAV is unique among the lentiviruses in that the initial acute febrile response and associated viremia are followed by recurrent cycles of the disease and, finally, a prolonged asymptomatic period (Montelaro et al., 1993). Some animals die during either the acute or chronic stage of the disease. If the animal survives, the disease episodes progressively decrease in frequency and intensity over about a year, after which time the animal enters the inapparent carrier stage (Cook et al., 1996).