[Freund's complete adjuvant in the chicken: efficient immunostimulation with severe local inflammatory reaction]

To quantify the enhancing activity of Freund's complete adjuvant (FCA), the humoral immune response of hens to the antigen human serum albumin (HSA) injected intramuscularly combined with FCA was measured. Local tissue reaction was examined on macroscopic and microscopic level. Other hens were injected with HSA in physiological sodium-chloride solution and served as controls. The immunization of hens without using FCA resulted in a short-term rise in immunoglobulin G (IgG) antibody titres, while the hens injected with HSA and FCA developed a long-term response (plateau-form of antibody titres). Local tissue reaction after injection of HSA in sodium-chloride solution was a mild and transient form of interstitial myositis. The immunization with HSA combined with FCA regularly resulted in a persisting granulomatous myositis. It is therefore a matter of animal protection to demand restricted use of FCA and to promote adjuvants of comparable efficiency, but better tolerance.