Vaccination against Eimeria magna coccidiosis using spray dispersion of precocious line oocysts in the nest box.

Coccidiosis mostly affects young rabbits just after weaning (5- to 6-week-old animals). Prevention of this disease must therefore be initiated before weaning. 'Precocious lines', derived from field species display good immunogenicity, though not pathogenic when administered at the right dose. In the present work, we tested the vaccination method of the whole litter at 25 days of age by spray dispersion of oocysts of a precocious line of Eimeria magna in the nest box. Three doses were tested, d1 = 4 x 10(2) oocysts, d2 = 4 x 10(3) oocysts, d3 = 4 x 10(4) oocysts. The animals were challenged individually with 10(4) oocysts of a wild strain of E. magna at 35 days of age, 5 days after weaning. The oocyst output and weight gain were recorded after vaccination and after challenge. The vaccinated animals did not display any vaccine reaction. The dose d3 was totally effective on oocyst output and on weight gain under our experimental conditions. As our challenge conditions were severe, we think that a lower vaccine dose could be used. This method proved to be efficient, and quick and easy to use because it did not require animal manipulation.