Chronic respiratory disease in the dog or cat is manifest primarily by persistent or recurrent cough, tachypnoea, progressive respiratory effort, and sometimes by loud breathing. The most common diseases that require constant management are asthma in the cat, chronic bronchitis in the dog or cat, bronchiectasis (more common in the dog than the cat), ciliary dyskinesia, eosinophilic lung disease in the dog, and some forms of interstitial lung disease. Appropriate therapy requires a complete diagnostic work-up and an individualized approach to treatment. Various options for therapy include aorticosteroids (oral or inhaled), antibiotics, antitussives and mucolytic agents. Additional interventions that should be considered include environmental improvements, control of obesity, nebulization and coupage, and home oxygen therapy. The chapter focuses on the following: Corticosteroids; Bronchodilators; Antibiotics; Antitussive agents; Mucolytic agents; Environmental control; Dietary therapy; Nebulization and coupage; and Home oxygen therapy.