HOW IMPORTANT IS IMMUNOGLOBULINE IN CANINE ATOPIC DERMATITIS?

Schiessl B*, Egli K�, Peel JE*, Roosje PJ�, Rudaz C*, Welle M�

Objectives: To establish a dog model for canine atopic dermatitis.

Design: The offspring of high IgE-responder Beagle dogs were sensitized from birth on to various allergens by repeated subcutaneous injections. Allergen specific serum IgE and IgG levels and skin testing were used as test parameters. The dogs were exposed to allergens (house dust mites) and examined weekly for clinical signs of atopic dermatitis.

Materials and Methods: Thirty eight Beagle dogs, including controls, were used for our experiments. Ovalbumine, recombinant birch pollen allergen, and house dust mite (Dermatophagoides farinae and Dermatophagoides pteronyssinus) extracts were used for subcutaneous sensitization. Cultures of the same house dust mite species were regularly spread on a carpeted bench in the kennels. Immunoglobuline levels were measured with ELISA techniques. Skin tests were performed by intracutaneous injection of the allergens and evaluated 20 minutes and 24 hours after injection.

Results: No skin disease could be provoked by subcutaneous injections, although specific immunoglobuline levels and skin test reactivity were high in sensitized (and zero in control) dogs

Conclusions: High specific IgE levels do not necessarily induce atopic dermatitis. Positive skin test reactions can be present without clinical signs. Therefore we conclude that other mechanisms are required in the pathogenesis of canine atopic dermatitis.