FC-31 Prevalence and characterization of house dust mites and house dust mite allergens collected from the bedding, skin and hair coat of dogs in southwest England

The house dust mites Dermatophagoides farinae and D. pteronyssinus are commonly used in diagnostic serological and intradermal tests for canine atopic dermatitis in the UK. However, there are few studies that have characterised the exposure of UK pet dogs to these mites. Objectives of this study were to determine the prevalence of mites and to characterise the mite species on skin, hair coat and bedding of pet dogs. A population of nonhospitalized pet dogs for which bedding was available for analysis was recruited irrespective of dermatological status (n = 34). Dust samples (n = 68) were collected from both dogs and their beds using a standardised vacuuming technique. Mites were identified using accepted morphological criteria. House dust mite allergen concentrations were assayed using a standardised ELISA for Der p 1 and Der f 1. Mites were identified in 15 of 68 samples (22%): D. pteronyssinus alone in three of 68, D. pteronyssinus in combination with storage or unclassified mites in five of 68, and storage or unclassified mites alone in seven of 68. Dermatophagoides farinae was not identified in any samples. Der p 1 allergens were detected in 37 of 68 samples (54%), and Der f 1 in four of 68 samples (5.9%). Contrary to studies elsewhere in Europe and North America, these findings support studies of human asthma patients in the UK where exposure to D. pteronyssinus is common, but rare to D. farinae. Given the high prevalence of positive intradermal and serological reactions to D. farinae in atopic dogs, further investigations are warranted to clarify potential cross-reactivity with other mite allergens. Funding: PetPlan Charitable Trust, Pfizer Animal Health.