Canine anti-leptospira bacterins commercialized in Brazil: a challenge made with indigenous strains of serovars Canicola and Copenhageni

Abstract

It was performed a comparative potency evaluation of canine anti-leptospira vaccines commercialized in Brazil, using for the challenge Canicola and Copenhageni leptospira indigenous strains isolated in Brazil. Nine polyvalent commercial bacterins to be used in dogs were were identified by letters A, B, C, D, E, F, G, H and I and compared. Challenge was made using strains L1-130 and LO4, respectively from Copenhageni and Canicola serovars, typified by the monoclonal antibodies technique. The adopted protocol was in agreement to American technical standards. Challenge infective dose for serovar Copenhageni was lower to the threshold established by the technical report and for Copenhageni serovar it was 10,000. Animals were observed during 21 consecutive days, and those which died of leptospirosis were counted. At the end of this period, survivors were euthanized with carbon dioxide and necropsied to collect kidneys and to perform culture to control leptospira kidney infection. Of the nine vaccines evaluated, seven were rejected for both serovars and two were approved against clinical disease and kidney infection for Canicola LO4, however they were only effective against clinical disease for Copenhageni L1-130serovar. Manufacturers laboratories of canine anti-leptospira bacterins commercialized in Brazil need to review the quality of their products regarding disease and infection protection against Canicola and Copenhageni serovars.