Canine atopic disease: the prevalence of positive intradermal skin tests at two sites in the north and south of Great Britain.

Results of intradermal skin test responses to the same panel of 53 allergens were compared in 118 dogs with atopic disease presented at two geographical centres, Edinburgh (87 cases) and London (31 cases). The allergens most commonly positive at both centres were human dander and Dermatophagoides farinae, but positive tests to all of the allergens used occurred in at least one case. The mean number of allergens to which positive tests resulted in atopic dogs was 5.126 (Edinburgh) and 5.129 (London). The majority of animals were sensitive to allergens from more than one group. A significantly higher number of positive reactors to house dust allergen was observed at London than at Edinburgh (P < 0.05), while a significantly higher number of positive reactions to grass pollens was detected at Edinburgh than in London (P < 0.05). Sensitivity to Dermatophagoides pteronyssinus, in the absence of sensitivity to D. farinae, was uncommon and therefore both of these mite allergens should be incorporated in intradermal skin testing panels in Great Britain.