SYSTEMIC APPROACH TO THORACIC RADIOGRAPHS: WHY IS THIS DOG COUGHING?

摘要

Coughing is a common presenting complaint in dogs and is seen with both respiratory and cardiovascular disease. Coughing is a reflex mechanism that occurs when cough receptors located throughout the respiratory tract (larynx, pharynx, and bronchi) arestimulated. Cardiac causes of cough include left-sided congestive heart failure with pulmonary edema and left mainstem bronchial compression secondary to left atrial enlargement. The most common cardiovascular diseases in the dog are chronic myxomatousdegenerative valve disease (endocardiosis) and dilated cardiomyopathy. Non-cardiac causes of cough are much more numerous and include diseases of the upper and lower airways and pulmonary parenchyma. Upper airway diseases that can cause cough include collapsing trachea, infectious tracheobronchitis, tracheitis, foreign body, or laryngeal and tracheal masses. Lower airway causes include feline asthma as well as chronic or eosinophilic bronchitis. Cats rarely, if ever, cough secondary to heart failure. Pulmonary parenchymal diseases include infectious and non-infectious pneumonia, neoplasia, non-cardiogenic pulmonary edema, and various interstitial lung diseases such as pulmonary fibrosis. Additionally, the same breeds of dogs that are predisposed to developing myxomatous degenerative mitral valve disease are also predisposed to several respiratory disease including tracheal collapse and chronic bronchitis.