The distribution of immunoglobulin-containing cells in canine small intestine.

Peroxidase conjugated antisera to canine immunoglobulins G and A and to human immunoglobulin M, have been used to study the distribution of immunoglobulin-containing cells in the small intestine of the young and adult dog. At all levels of the small bowel of the adult dog, IgA:IgM:IgG cells have a 2:1:1 ratio while the greatest number of immunocytes is found in the duodenum and decreases towards the distal portion of the small intestine. The young puppy shows a predominance of IgM-containing cells in the small intestinal lamina propria during early life but the adult pattern of immunocyte distribution has been achieved by weaning.