EN
The subjects were 13 horses, of which 5 clinically healthy ones were infected intranasally and intraconjunctivally with a suspension of two subtypes of the influenza virus: A/equi/1 and A/equi/2, and 3 were control animals. The remaining 5 horses became ill in a natural way. In the early phase of injection, the haematological determinations showed in the experimental horses a decrease in the lcucocyte, lymphocyte, neutrophil, and platelet counts. The changes in the values of erythrocyte indices (red blood cell count, haemoglobin content, and packed cell volume) were more weakly marked, though a tendency to decrease their value occurred. Similar results were obtained in the animals naturally infected with equine influenza virus although their cxamination was started only from the 6th day of illness.