Canine Secretory Immunoglobulins: Identification of Secretory Component

Abstract

Immunoglobulin A was demonstrated in canine tracheal secretions, saliva, tears, nasal secretions and colostrum. Another molecular species, presumably canine secretory component, was demonstrated in colostrum, tracheal secretions and tears. The IgA in colostrum was purified by a combination of Sephadex G-200 and DEAE-cellulose chromatography, and an antiserum which reacts with IgA and secretory component was prepared against this purified IgA. Immunoglobulins G, A and M were measured semiquantitatively in colostrum and milk and compared to serum values. Immunoglobulin A has the highest colostrum to serum ratio, IgG has the next highest and IgM is usually found in higher concentration in serum than in colostrum. The actual concentrations of IgG, IgA and IgM in the colostrum, however, varied widely among the six dogs studied.