EN
The study was carried out in 13 Polish Primitive Horses.Ten of them were subjected to stress and infected with equine influenza virus (the mixture of subtype A-equi/1 and A-equi/2). Three horses were left as controls. The coagulation time by Lee and White method and caolin-kephalin and prothrombin times in plasma citrate were determined with a coagulometer. Concentration of fibrinogen (Quick method) and platelet count (procaine method) were determined as well. The means of the above parameters before and after infection in relation to the values in control animals were compared. The results of the experiment show that the caolin-kephalin and prothrombin times have been shortened in infected horses, the platelet count has been decreased and the concentration of fibrinogen has been increased. The changes in the coagulation system were statistically significant. Thus the results of the experiment have confirmed the hypothesis that in the course of influenza infection disturbances in the coagulation system may occur.