Injection site reactions and antibody responses in sheep and goats after the use of multivalent clostridial vaccines.

Uncertainty concerning the use, efficacy and possible adverse effects of clostridial vaccination in goats prompted a study of the injection site reactions and antibody responses in 40 goats and 40 sheep. The vaccines used were Covexin 8, Heptavac and Tasvax 8. In all the animals swellings averaging 2.5 cm in diameter were present at the injection site seven days after vaccination and were still apparent 28 days after vaccination. The injection site reactions could not be attributed to faulty vaccination technique because they did not occur in a control group injected with sterile water. By 14 days the reactions were significantly larger in sheep than in goats and by 28 days the reactions to Covexin 8 were larger than those to the other vaccines in sheep and goats. Serum antibody was present in all groups before vaccination and, with the exception of the goats vaccinated with Heptavac, increased 14 days after vaccination. The increase was greater in sheep than in goats. By 28 days antibody levels had declined in all but the sheep vaccinated with Heptavac in which a further increase occurred. At that time, the antibody levels in vaccinated sheep were still higher than in the unvaccinated sheep whereas the antibody levels in vaccinated goats were no longer different from those in the control goats. These results suggest that there is a difference between the vaccines used and between the responses of the two species and support the clinical observation that the protection afforded to goats by multivalent clostridial vaccines is poorer than that afforded to sheep.