Intradermal testing and allergen-specific IgE testing in dogs with eosinophilic bronchopneumopathy and healthy dogs

Hypersensitivity reactions are considered as a potential etiology of canine eosinophilic bronchopneumopathy (EBP).

To investigate positive reactions in intradermal allergy testing (IDT) and allergen-specific serum immunoglobulin E (IgE) testing in dogs with EBP and healthy control dogs, and to compare the results between groups.

Twenty-one dogs diagnosed with EBP and 22 healthy controls were included in the prospective case-control study. IDT with 41 allergens and an Fc-ε receptor-based serum test for allergen-specific IgE of 23 allergens were performed. Positive reactions were compared between groups using Pearson's Chi-squared test and false discovery rate correction for multiple testing. Agreement between the two test methods was evaluated with Cohen's Kappa test. The p-value was < 0.05 for all tests.

Dogs with EBP showed significantly more median positive reactions in IDT [8.0 (5.0-12.0)] compared to healthy control dogs [4.0 (1.0-8.0; p = 0.04)], but there was no difference in median positive reactions in serum IgE tests between dogs with EBP [11.0 (7.5-14.5)] and control dogs [11.0 (7.25-14.0; p = 0.36)]. Agreement between the results of both allergy testing methods was classified as minimal (κ = 0.14).

Dogs with EBP are more likely to show positive reactions in IDT compared to healthy control dogs. However, similar findings in healthy controls and poor agreement with serum IgE results limit conclusions regarding clinical relevance. Thus, IDT and serum IgE results should be interpreted cautiously and in the context of clinical findings.