Objective—To evaluate fecal concentrations of
selected genera of colonic bacteria in healthy dogs,
and to investigate effects of dietary fructooligosaccharides
(FOS) on those bacterial populations.
Animals—6 healthy adult Beagles.
Procedure—Dogs were randomly assigned to 2
groups of 3 and fed an unsupplemented diet for 370
days. After 88 days, fecal samples were collected.
Another fecal sample was collected from each dog
282 days later. Group A then received a diet supplemented
with FOS, and group B continued to receive
the unsupplemented diet. Twenty-eight to 29 days
later, fecal samples were collected. Diets were
switched between groups, and fecal samples were
collected 31 and 87 days later. Concentrations of
Bifidobacterium spp, Lactobacillus spp, Clostridium
spp, Bacteroides spp, and Escherichia coli in freshly
collected feces were determined. Effects of diet and
time on bacterial concentrations were compared
Results—Bifidobacterium spp and Lactobacillus spp
were inconsistently isolated from feces of dogs fed
either diet. Sequence of diet significantly affected
number of Bacteroides spp subsequently isolated
from feces, but diet had no effect on numbers of
Clostridium spp or E coli.
Conclusions and Clinical Relevance—Some genera
of bacteria (eg, Bifidobacterium) believed to be common
components of colonic microflora may be only
sporadically isolated from feces of healthy dogs. This
deviation from expected fecal flora may have implications
for the effectiveness of supplementing diets
with prebiotics. (Am J Vet Res 2000;61: