EIMERIA SP FROM THE RABBIT (ORYCTOLAGUS-CUNICULUS) - PATHOGENICITY AND IMMUNOGENICITY OF EIMERIA-INTESTINALIS

The pathogenicity and immunogenicity of Eimeria intestinalis was evalu ated in SPF rabbits. The animals were given immunizing doses of 6, 6 x 10(2) , 6 x 10(3), and 6 x 10(4) sporulated oocysts and were challeng ed with 3 x 10(3) oocysts. The criteria analysed were the daily weight gain and the oocyst output. This study showed that E. intestinalis ha d strong immunogenicity, as the inoculation of 6 oocysts was sufficien t to minimize the clinical expression of the disease following the cha llenge and to reduce the oocyst output by about 60%. The immunity towa rds the excretion of oocysts and the illness was absolute in animals i noculated with 600 or more oocysts. Moreover, this protection seemed t o be efficient at least 8 weeks after the challenge. The present resul ts also confirm the pathogenicity of E. intestinalis, although the occ urrence of diarrhoea may be irregular, and emphasize the fact that the capacity of this Eimeria for multiplication is not a criterion for cl inical diagnosis of the disease.