PROTECTION OF GOATS AGAINST EXPERIMENTAL ENTEROTOXEMIA BY VACCINATIONWITH CLOSTRIDIUM-PERFRINGENS TYPE-D EPSILON TOXOID

Enterotoxaemia in goats is mainly characterised by enterocolitis, and it has been suggested that the poor efficacy of commercial vaccines in preventing the disease is due to the local action of Clostridium perf ringens toxin/s within the intestine, where circulating antibodies mig ht not exert their action. Five goat Bids were vaccinated with an inco mplete Freund's adjuvant C perfringens type D epsilon toxoid vaccine o n three occasions at three-week intervals, four similar kids were vacc inated with a commercial enterotoxaemia vaccine at the same times, and five other unvaccinated kids were used as controls, All the animals w ere challenged intraduodenally, one week after the last vaccination,,v ith C perfringens type D filtered culture supernatant. At the time of challenge, the level of epsilon toxin antibodies in the serum of the F reund's adjuvant-vaccinated kids ranged between 2.45 and 230 iu/ml, wh ile the kids that received the commercial vaccine had levels between 0 .22 and 1.52 iu/ml, and the unvaccinated kids had levels below 0.03 in /mi, No clinical or postmortem changes were observed in the kids that received the Freund's adjuvant-vaccine. Three of the four kids that re ceived the commercial vaccine developed mild, pasty diarrhoea, with a slight reddening of the colonic mucosa being observed postmortem, All the unvaccinated kids developed severe diarrhoea, respiratory distress and central nervous system signs, and were killed humanely between si x and 24 hours after challenge. The postmortem changes consisted of ps eudomembranous colitis, lung oedema and perivascular oedema of the bra in, Moderate to high serum levels of anti-epsilon antibody appeared to protect the goats against both the systemic and the intestinal effect s of C perfringens type D toxins.