P‐44 The presence of dust mite species in the environment of dust mite‐sensitized atopic dogs

Abstract

Dust mites (DM), especially Dermatophagoides farinae (DF), are the most common offending aeroallergens in atopic dogs. The aim of this study was to compare the DM species in the households of atopic dogs (Group A, n = 8) that reacted intradermally to DF, D. pteronyssinus (DP), Acarus siro (AS), Lepidoglyphus destructor (LD) and/or Tyrophagus putrescentiae (TP), to DM species in households of nonatopic dogs (Group B, n = 4) and households without pets (Group C, n = 8). Group A dogs exhibited perennial pruritus, were free of pathogenic mites and fleas, did not respond to an elimination diet, and fulfilled the diagnostic criteria for atopic dermatitis. All Group B dogs tested ID negative and had no dermatological problems. Dust samples were vacuum collected in a standardized fashion from two sites of the dog living quarters, one time for each season. DM quantitation was made stereoscopically and their species identification by microscopy. DM median number in Group A was 1.5 for DF, 0.5 for DP and 0 for the other three species. One of eight, one of four and one of four dogs were sensitized to DF, AS and TP, respectively, despite the absence of these species from their environment. No difference could be found in terms of DM species between the three groups (lowest P value = 0.06). In conclusion, cross‐sensitization between DM or irritant intradermal test reactions to their allergenic extracts may be common, and no preferential overpopulation of DF can explain the frequent sensitization of atopic dogs to this mite. Funding: Self‐funded.