A microdissection technique was used to investigate the flora of the canine skin surface and hair follicle. Anaerobic incubation revealed a species of Propionibacterium on the skin of seven of 11 normal dogs. The organism had cultural and biochemical similarities to Propionibacterium acnes. Analysis of the distribution of the organism revealed significant differences between carriage on males and females, between dogs with long and shorthaired coats and between dogs with coarse and fine hair. When present, the regional distribution of P acnes was similar to that found on man, with higher numbers found on the trunk than on the feet.