The antibody response of cattle to Clostridium botulinum types C and D toxoids.

The resistance of cattle with varying serum-antitoxin titres was determined by per os challenge. The results proved that a solid immunity can be produced against C. botulinum toxins C1 and D. The immune response of cattle to various quantities of C. botulinum C1 and D toxoids, aluminium-phosphate-adsorbed and in water-in-oil emulsion was investigated. The response to antigen in water-in-oil emulsion was far superior to the other when they were used for primary and secondary stimuli. When cattle had been given a solid basic immunity with 2 injections of antigen in water-in-oil emulsion, essentially the same booster effect was obtained with antigen in water-in-oil emulsion and in aqueous solution. Only some of the animals injected intramuscularly with antigens in water-in-oil emulsion developed local lesions. These lesions were not large and their histological picture indicated a noticeable decline in severity within 20 weeks. A case is thus made out for the use of C. botulinum C1 and D toxoids in water-in-oil emulsion for the primary and secondary stimuli and an aqueous solution of these antigens for any booster stimulus as an improved method of protecting cattle against botulism.