Evaluating immune function in domestic animals

Dexamethasone administration has been widely used as a model of immunosuppression in various species. The objective of the work reported here was to evaluate immune function in pigs treated with dexamethasone. Experiment 1 pigs were assigned to either Control (n=10) or 2 mg/kg Dexamethasone (n=10) treated groups. Treatments were administered 48 and 24 hours prior to immune function testing. The dexamethasone treated pigs received the drug on 22 of 72 experimental days. Pigs in Experiment 2 were assigned to one of three groups: Control (n=10), 2 mg/kg dexamethasone (n=10), or 6 mg/kg dexamethasone (n=10). Treatments were given once and immune functions were evaluated three and 27 hours after treatment. Lymphocyte blastogenesis, total and difTerential white blood cell count, and several measures of in vitro neutrophil function were measured in both experiments. Antigen specific antibody production, growth rate, and organ weights at necropsy were also measured in Experiment 1. There were no consistent changes in neutrophil functions in these experiments. Lymphocyte blastogenesis to concanavalin A and poke weed mitogen was significantly (P<0.05) enhanced during