Allergic respiratory disease.

Allergic rhinitis and extrinsic allergic alveolitis are the most common allergic disorders of the bovine respiratory system. Environmental and management factors play significant roles in the pathogenesis of these disorders. When compared to infectious or toxic respiratory disease, allergic respiratory disease is relatively rare and of far less economic importance in North American cattle; however, the environmental and management conditions conducive to these diseases exist in many regions. Therefore, familiarity with the clinical and epidemiologic features of these unique diseases will aid the veterinarian in establishing an accurate diagnosis. Signs of respiratory dysfunction are common to anaphylactic and anaphylactoid reactions. Early recognition of these adverse reactions will provide the practitioner with the greatest chance of successful treatment.