IMPACT OF VIRAL HEMORRHAGIC-DISEASE ON A WILD POPULATION OF EUROPEAN RABBITS IN FRANCE

An outbreak of rabbit viral hemorrhagic disease (RVHD) and of myxomato sis occurred in a free-living population of rabbits (Oryctolagus cunic ulus) near Paris (France) in 1995. Annual mortality rates were 88% in adults and 99% in juveniles. There was no difference in mortality rate s between males and females. Since most adults were protected with myx oma antibodies after May, they probably died of RVHD. Mortality lasted throughout the year despite high proportions of rabbits having develo ped myxomatosis and RVHD antibodies, which suggests that the combinati on of the two diseases and the immunosuppressive characteristics of my xoma virus could be responsible for the mortality caused by RVHD. The proportion of juveniles with RVHD antibodies increased with their weig ht. Seroconversion against RVHD occurred in spring and autumn.