Investigations on oxidative stress and the stages of clinical Peste des petits ruminants in goats under natural infection

Over the years, there has been an ongoing search for the control and management of Peste des petits ruminants (PPR), an OIE listed disease. A lot has been elucidated on its epidemiology, clinical manifestations and pathologic findings, but none on the oxidative stress pattern in affected animals. Most oxidative stress studies have focused on chronic conditions, while PPR is an acute/subacute disease. This study investigated the stage by stage serum level of biomarkers of oxidative stress during the clinical manifestation of Peste des petits ruminants in goats under natural infection. Twenty unvaccinated male goats naturally exposed to PPR virus were used for this study. Following the manifestation of clinical signs, the goats were grouped, according to the severity of clinical manifestations, into pre-clinical (group I), early-clinical (group II), mid-clinical (group III) and terminal (group IV). Serum biomarkers investigated include superoxide dismutase, malondialdehyde and catalase. The neutrophil/lymphocyte ratio (NLR) and other serum electrolytes were also used as biomarkers for evaluating physiologic stress in affected animals. Results showed serum catalase significantly increased at the mid and terminal stages of PPR, while serum malondialdehyde significantly increased at the terminal stage. The NLR and the Ca/P ratios were also significantly increased in all clinically affected animals. Oxidative stress in PPR depends on the stage of clinical manifestations, with serum catalase and malondialdehyde being better biomarkers than superoxide dismutase in naturally infected goats. Also, NLR and serum Ca/P are good indices for monitoring systemic/physiologic stress in goats affected by PPR.