Most of the knowledge about pathogenicity and vaccine development in brucellosis is based on studies of the smooth species Brucella abartus, Brucella suis and Brucella melitensis. As B.ovis and B.canis share the common feature of being pathogenic rough strains, it is tempting to extrapolate the knowledge and strategies used for the development of the vaccine for ovine brucellosis to the development of a vaccine for canine brucellosis.