Control of paratuberculosis (Johne's disease) in goats by vaccination.

After several years of unsuccessful efforts to eradicate paratuberculosis in goats in Norway by conventional methods such as general hygienic precautions and the isolation and slaughtering of clinically affected and serologically positive animals, a vaccination programme was initiated in 1967. The vaccine used consists of two live attenuated strains of Mycobacterium paratuberculosis suspended in a mixture of liquid paraffin, olive oil and pumice powder. The vaccine may be stored at 4 degrees C for two weeks, the dose is 1 ml and the goat kids are vaccinated at the age of two to four weeks. The efficacy of the vaccine has been judged mainly by post mortem examination of vaccinated and unvaccinated goats in the period 1967-82. During this period about 131,000 goats were vaccinated and, based on the post mortem examination of 15,219 goats, the infection rate was reduced from 53 to 1 per cent. Moreover, infection occurred almost exclusively in goats which for some reason or other had not been vaccinated or which had been too old when vaccinated. The results of these examinations showed that the adjuvanted vaccine with live M paratuberculosis bacteria offers a high degree of protection against paratuberculosis in goats.