The toxicity of T-2 toxin in swine following topical application: II. Effects on hematology, serum biochemistry, and immune response

Abstract

T-2 toxin at 0 (6 pigs) or 15 mg/kg (8 pigs) in 0.75 ml of dimethyl sulfoxide was topically applied to 9- to 10-week-old, male castrated, specific-pathogen-free derived pigs which were immunized subcutaneously with sheep red blood cells (SRBC) on Days 0 and 21. Whole blood and serum samples were taken periodically for clinical pathologic and immunologic evaluations. The pigs were observed daily and weighed weekly; their rectal temperatures were measured periodically. The T-2-treated pigs displayed anorexia, lethargy, posterior weakness and paresis, persistent high fever, and reduced body weight gain. Prominent neutrophilia, decreased serum glucose, albumin, and alkaline phosphatase activity, and increased serum globulin were seen in the T-2-treated group. The responses of enriched peripheral blood mononuclear cells to mitogens concanavalin A, phytohemagglutinin, and pokeweed mitogen of the T-2-treated group were significantly lower than those of the control group both at early (3 to 5 days) and late (20 to 28 days) postdosing intervals. No significant effects were noted in the hemagglutination titer to SRBC. Thus, in addition to the severe local dermal injury reported previously, topical exposure of swine to a sublethal dose of T-2 toxin, 15 mg/kg, can cause significant systemic effects on parameters such as body weight gain, rectal temperature, hematology, serum biochemistry, and cellular immune response.