Scanning electron microscopic study of the small intestine of dogs from birth to 337 days of age.

The surface morphology of the small intestine of dogs from birth to 337 days of age was studied by scanning electron microscopy. The small intestinal surface morphology was similar to that described for other species, except for irregular villous length in the duodenum, jejunum, and ileum of the dog from birth to 21 days of age. The absorptive epithelial cells and goblet cells were similar in morphology and distribution from birth to 337 days. Segmented filamentous bacteria were attached to the ileal mucosa of dogs 54 to 161 days of age.