The purpose of this study was to evaluate some parameters of non-specific immunity [myeloperoxidase (MPO) activity in PMN cells and lysozyme (LZM) concentration and activity in serum] in rabbits experimentally infected with 4 Czech strains of the rabbit haemorrhagic disease (RHD) virus: CAMPV-351 (reference strain), CAMP-561, CAMPV-562, CAMPV-558. Furthermore, mortality was recorded among the animals infected with four Czech strains of the RHDV. Statistical analysis revealed that the most numerous changes were caused by reference strain CAMPV-351, followed by strains CAMPV-562 and CAMPV-558, and strain CAMPV-561. The highest mortality (100%) was observed in animals infected with this last strain.