Abstract
The biochemical characteristics of group G streptococci isolated from cats were markedly similar to the characteristics of group G streptococci from man. Both cat and human isolates of group G streptococci were also very similar in biochemical characteristics to group A streptococci so that to identify the source of group G streptococci by biochemical reactions is not a reliable procedure. The group G streptococci found in many cats could be pathogenic to man, since their physiological and biological characteristics are very similar to those of group A streptococci.