Insights into Canine Idiopathic Rhinitis from a Prospective Study: A Multimodal Diagnostic Perspective

Introduction: Idiopathic rhinitis (IR) is one of the most common causes of chronic nasal discharge in dogs. It is a diagnosis of exclusion requiring a comprehensive diagnostic work-up to rule out other differentials. To investigate a possible allergic etiology, allergen-specific IgE antibody superclasses were evaluated. Methods: Dogs with chronic nasal discharge underwent blood testing, whole-body CT, and detailed evaluation of the nasal cavity. Dogs with systemic diseases or corticosteroid treatment within two weeks prior to presentation were excluded. Results: A total of 46 dogs were included: 13 IR, 10 malignant tumors, six benign tumors, eight other inflammatory nasal diseases, and nine controls. All IR dogs were non-brachycephalic and of various breeds. No correlation was found between sinusitis, turbinate destruction, culture-based bacteriology, or IgE positivity. A similarly high number of positive IgE results was observed across all groups. Regarding treatment and follow-up, compared to dogs with other nasal diseases, compliance among IR dog owners was comparably poor. Conclusions: Allergen-specific IgE may be elevated in dogs with IR; however, they are neither diagnostic nor predictive. As owners often perceive the disease as a harmless cold, awareness must be raised about the nasal functions in dogs and possible consequences of untreated nasal discharge.