Experimental anaphylaxis in cattle

Abstract

Ayrshire calves were sensitised to ovalbumin by one intravenous injection and/or to horse serum by two intravenous injections, separated by an interval of not less than 7 days. Challenge by the same route after a latent period of at least seven days produced immediate acute systemic reactions. The outstanding features of these reactions were dyspnoea, coughing, pulmonary hypertension, systemic hypotension and increased salivation, lacrimation and nasal discharge. The severity of the reaction increased with the challenge dose of antigen. Pathological changes were largely confined to the respiratory tract.