Characterization of induced homocytotropic antibody to ragweed and timothy pollen in non-atopic dogs.

Homocytotropic antibody induced with ragweed and timothy pollen extract has been produced in non-atopic dogs. Characterization of the antibody was carried out by direct skin tests, passive transfer, tanned red cell haemagglutination, Sephadex filtration and immunoelectrophoresis. Two types of antibody were induced. A 7S antibody which had skin sensitizing characteristics and a 19S antibody which was the haemagglutinating antibody and 2ME sensitive. The findings are similar to that seen in spontaneous canine atopy except that the dogs did not respond with respiratory or systemic symptoms after antigenic challenge.