Canine saliva was tested for its bactericidal effects against pathogens relevant to the presumed hygienic functions of maternal grooming of the mammary and anogenital areas and licking of wounds. Both female and male saliva were bactericidal against Escherichia coli and Streptococcus canis but only slightly, and nonsignificantly, bactericidal against coagulase positive staphylococcus and Pseudomonas aeruginosa. E. coli is the cause of highly fatal coliform enteritis of neonatal mammals and E. coli and S. canis are the main pathogens implicated in neonatal septicemia of dogs. The bactericidal effects of saliva would facilitate the hygienic function of maternal licking of the mammary and anogenital areas in protecting newborns from these diseases. E. coli and S. canis along with coagulase positive staphylococcus and P. aeruginosa are among the common wound contaminants of dogs. Wound licking, and the application of saliva, would thus reduce wound contamination by E. coli and S. canis. The resistance of staphylococcus to bactericidal effects of saliva may be a factor in the high frequency (46 percent) with which coagulase positive staphylococcus was isolated from wounds compared with much lower frequency (9-17 percent) with which E. coli and S. canis were isolated.