Incidence of anti-Der f 2 and anti-Zen 1-specific immunoglobulin E antibodies in atopic dogs from South-East England.

Recent studies from North America and continental Europe have reported Zen 1 as a major allergen in atopic dogs, and Der f 2 as a minor allergen. In contrast, Der f 2 is considered a major allergen in Japan. In this study, allergen-specific IgE against Der f 2, Zen 1 and crude Dermatophagoides farinae (DF) was determined using ELISA assays in English atopic dogs. Serum samples were obtained from 59 dogs with non-seasonal atopic dermatitis. ELISA assays using horseradish peroxidase-labelled anti-dog IgE monoclonal antibody (Bethyl; A40-125P) and recombinant Der f 2 (Zenoaq), natural Zen 1 (Zenoaq) and DF extract (Greer Laboratories; North Carolina) were performed by Zenoaq, Fukushima, Japan. The mean optical density (OD) of each sample was determined and the cut-off value was calculated from OD readings obtained from four healthy control dogs. Der f 2, Zen 1 and DF-specific IgE antibodies were found in the serum samples taken from 57 (97 per cent), 45 (76 per cent) and 47 (80 per cent) atopic dogs, respectively, suggesting that both Zen 1 and Der f 2 are 'major allergens' in the South-East England.