Three groups of swine (6 per group) were used to determine hemodynamic and blood flow alterations induced by T-2 toxin. Two groups were dosed at 0.6 or 2.4 mg/kg T-2 toxin, and one group served as a vehicle control (70% ethanol). Organ blood flow was determined at 0 hr (predosing) and at 90-min intervals for 6 hr postdosing using 15-micron diameter radionuclide labeled microspheres injected into the left atrium. Hemodynamic parameters were obtained at the same time points. The infusion of T-2 toxin resulted in reductions in cardiac output. This trend appeared to reverse itself in the low dose animals after 3 hr, whereas in the high dose group, cardiac output continued to decline. Mean aortic pressure (MAP) declined in a dose dependent fashion which tended to parallel the reduction observed in cardiac output. Heart rate was increased in both groups treated with T-2 toxin. Blood flow, to the brain, heart, and kidneys decreased following exposure to the toxin. The relative percentage of cardiac output received by these organs, however, was maintained despite the drop in blood flow. Pancreatic and splenic blood flows were the most severely compromised as a result of T-2 toxicosis. Consequently, the percentage of cardiac output going to the pancreas and spleen was dramatically reduced. Adrenal, hepatic, and total gastrointestinal blood flows increased or did not change from control values. As a result, the percentage of cardiac output supplying these organs increased.