Intradermal testing in healthy horses and horses with chronic obstructive pulmonary disease, recurrent urticaria, or allergic dermatitis.

This study investigates the reaction of horses to allergens injected under the skin, comparing healthy horses to those suffering from chronic obstructive pulmonary disease, recurrent urticaria, and allergic dermatitis. The findings highlight that horses with these conditions significantly react to more allergens than healthy ones and stress the importance of matching allergen reactivity with individual horse’s history and potential exposure to allergens.

Scope and Methodology of Research

• The research is a case-control study initiated to draw comparisons between the responses of healthy and diseased horses to a series of allergens injected under the dermis (skin layer).
• The study focused on three diseases: chronic obstructive pulmonary disease (COPD), recurrent urticaria (RU), and atopic dermatitis-insect hypersensitivity (allergic dermatitis [AD]).
• The study involved a total of 86 horses, with an undisclosed division between healthy and affected horses.
• The research involved testing the reactions to injected allergens from several groups including molds, weeds, trees, grasses-crops, and insects.
• The reactions of the horses to the allergens were observed and recorded at three separate intervals: 30 minutes (immediate reaction), 4 hours (late-phase reactions), and 24 hours (delayed-phase reactions) post-exposure.

Key Findings

• The study found that horses affected by COPD, RU, and AD had significantly more positive reactions to the injected allergens across all categories at all observed times than those which were healthy.
• Parallelly, the diseased horses reacted to a greater number of allergens in each allergen group when compared to healthy horses.

Conclusions and Recommendations

• The research concludes that reactions to individual allergens should not be used as a standalone parameter to discern hypersensitivity in horses.
• It suggests that the overall pattern of allergen reactivity can be beneficial to manage the conditions associated with hypersensitivity to environmental allergens, especially when these findings are cross-verified with a detailed history of the horse and potential exposure to allergens.