Negative environmental impact can often adversely affect the functional properties of piglets and significantly weaken their viability. It is often possible to judge this by the dynamics of the activity of hemostasis indicators. The level of activity of platelets and coagulation systems very early change activity in the case of negative influences from the outside, causing the appearance of overt hemostasiopathy. This condition leads to the disruption of hemocirculation in the capillaries and a decrease in the severity of metabolism in the tissues. These changes lead to a slowdown in growth and a general weakening of animals, thereby leading to great economic damage. It was found that the appearance of transport stress in piglets leads to increased platelet aggregation and activation of homocoagulation mechanisms during inhibition of fibrinolysis. Due to the fact that this situation is very common, the possibility of eliminating these dysfunctions was studied. The study tested fumaric acid at 0.1 g/kg in the form of a feed additive for 20 days in piglets that underwent long-term transportation. As a result of using this supplement, it was possible to reduce platelet activity and blood coagulation and increase fibrinolysis activity, bringing them to control values. As a result of the study, it was found that the intake of fumaric acid in the body of piglets that have experienced the influence of a high-intensity medium optimizes the functional status of their hemostasis. This minimizes their risk of microthrombosis and weakened animal growth.