Lactobacillus salivarus has been studied extensively as a probiotic in human . However the ability of an organism to survive passage through the intestinal tract and exert beneficial effects can not be directly extrapolated between species. This study evaluated the ability of L.salivarus to survive gastrointestinal transit in dogs and assessed whether oral administration of L.salivarus is safe in order to determine whether studies evaluating the efficacy of L.salivarus in the treatment of canine disease are indicated. Dogs were divided into 5 groups receiving doses of 0 (control group n=8),1 109 (group 1, n=8), 1 1010 ( group2 ,n=8) , 5 1010 (group3, n=8) and 5 1011 (group 4,n=8) colony forming unite per day orally for 5 days. L.salivarus was detected in the feces of 3/8 dogs in group 1 and 2, 4/8 dogs in group 3; 8/8 dogs in group 4 and 0/8 dogs in control group. Fecal colonization was significantly greater in group 4 than in any other groups (P> 0.01). Differences between groups 1,2 and 3 were not significant. No adverse effects were noted. Fecal colonization of L.salivarus in dogs is somewhat variable; however clinical studies are indicated to evaluated this organism in the treatment and prevention of canine disease.