Canine copra-immunoglobulins

Canine intestinal secretions from the jejunum, terminal ileum, and proximal colon, contain qualitatively the same immunoglobulins as the serum and colostrum. Secretory IgA is present in the fecal extracts in approximately 4 times the concentration in serum. A procedure for minimizing bacterial and enzymatic proteolysis of the fecal immunoproteins and for separating the major classes of immunoglobulins, particularly secretory IgA, is outlined. The purified secretory IgA shares antigenic similarities with IgA in serum and other canine secretions, and data about the sedimentation behavior, size, and polypeptide chains of the molecule are given. The isolated IgA retains biological activity. The canine secretory IgA isolated from colostrum and fecal extracts appears to be the same molecular species.