Occurrence of vaccine abscesses in bovines after the administration of bivalent foot-and-mouth disease vaccine

Abstract

ABSTRACT The aim of the present study is to identify the occurrence of abscesses in cattle after the administration of bivalent foot-and-mouth disease vaccine as adverse reaction to components in the new commercial vaccine formulation. Thirty bovines were divided into three groups composed of 10 animals, each. Groups 1 and 2 were vaccinated by researchers based on good vaccination practices criteria. Group 1 was intramuscularly administered with the vaccine, Group 2 received it through subcutaneous route and Group 3 was vaccinated by breeders through subcutaneous route. Animals were selected and observed in vivo in three different moments (7, 28 and 45 days after vaccination). Subsequently, they were observed during post mortem inspection in order to assess the occurrence of vaccine abscesses. Vaccine abscesses were recorded in 40% of bovines in Group 1, in 50% of the ones in Group 2 and in 60% of those in Group 3. There was no significant difference between experimental groups based on the Chi-square test and on Cramer's V analysis; there was no significant difference among experimental groups. Excess of carcass parts presenting vaccine abscesses during post mortem inspection resulted in the meat loss of 1.775 kg in Group 1, of 2.303 kg in Group 2 and of 3.268 kg in Group 3. In conclusion, despite changes in bivalent foot-and-mouth disease vaccine formulation, care should be taken at vaccination time to minimize the occurrence of vaccine abscesses and, consequently, meat losses at slaughter, as well as to reduce losses in beef production chain.