Equine Viral Arteritis (EVA) is a major infection disease of horses. In many cases the stallions recovered from the EAV infection are the source of the virus for other horses, shedding the virus with semen. Their elimination is most important in prevention of that disease. The stallions should be checked serologically for the presence of anti-EAV antibodies in their sera. If the stallion is serologically positive, semen samples are checked for the virus. The overall goal of the study was to find seropositive stallions among 476 stallions from 4 herds in Poland. The percentage of shedders was between 9,38% – 25% in different herds. The trials of decontamination of stallions’ sperm from EAV were the specific object of the study. The purification is obtained by the centrifugation of the infected sperm in a density gradient. Material for the study consisted of 21 semen samples. The samples were treated with Equi Pure gradient of Nidacon (Sweden). The results showed that only some of the EAV-infected semen samples were cleaned off from the EAV infection. Centrifugation in gradient did not decrease the motility of spermatozoa. The percentage of morphologically normal spermatozoa was higher after purifying in comparison with the raw semen. Generally, the quality of stallion semen after centrifugation was satisfactory and it could be used for artificial insemination of mares.

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