Feline Asthma and Chronic Bronchitis: NAVLE Study Guide

The Core Distinction: Asthma vs. Chronic Bronchitis

Feline lower airway disease almost always boils down to two diagnoses: asthma and chronic bronchitis. They look similar clinically and radiographically, but the underlying pathology is different — and the NAVLE tests whether you know which is which.

Feline asthma is a reversible, type I hypersensitivity-mediated bronchoconstriction. An allergen triggers mast cell degranulation → bronchospasm, mucus hypersecretion, and airway edema → air trapping → hyperinflation. The airways can normalize between episodes. Siamese and other Oriental breeds are disproportionately affected. Young to middle-aged cats are the classic demographic, though any cat can develop it.

Chronic bronchitis is irreversible airway remodeling from persistent inflammation. It tends to affect older cats. The inflammation is predominantly neutrophilic rather than eosinophilic. Cats with chronic bronchitis may not respond as well to corticosteroids as asthmatic cats do. The two conditions overlap — a cat can have both — and distinguishing them requires BAL cytology.