Feline asthma/bronchial disease

Feline lower airway disease is typified by wheezing and bouts of coughing. Whether it is true asthma which represents spasm of the airways, or bronchitis which is associated more with inflammatory change causing narrowing of the airway is difficult to assess due to the inability to perform the type of pulmonary function tests that are undertaken in humans. In studies of feline lower airway disease that have been undertaken, Siamese and other Oriental cats appear to be over-represented. As asthma in humans has a hereditary component, it is speculated that there may be a hereditary component to the disease in cats, but any genetic predisposition has yet to be identified.

Moise N.S., Wiedenkeller D., Yeager A., Blue J.T. & Scarlett J. (1989) Clinical, radiographic and bronchial cytology features of cats with bronchial disease: 65 cases (1980-1986). JAVMA 194 1467-1473
Dye J.A., McKiernan B.C., Rozanski E.A., Hoffman W.E., Losonsky J.M., Homco L.D., Weisiger R.M. & Kakoma I. (1996) Bronchopulmonary disease in the cat: Historical, physical, radiographic, clinicopathologic and pulmonary functional evaluation of 24 affected and 15 healthy cats. JVIM 10 385-400
Adamama-Moraitou K.K., Patsikas M.N. & Koutinas A.F.  (2004) Feline lower airway disease: a retrospective study of 22 naturally occurring cases from Greece. JFMS  6 227-233

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis has been seen in a number of cats, most of which were middle aged to older (average ~9 years), with no apparent sex or obvious breed predisposition, although Persian cats may have been over-represented. Affected cats show respiratory distress and coughing, with clinical signs being present for <6 months in most cases. Physical abnormalities included rapid breathing with inspiratory or mixed inspiratory and expiratory effort, and adventitial lung sounds. The cause is unknown. Radiographic changes included dense patchy or diffuse interstitial, bronchiolar, and alveolar infiltrates. Analysis of bronchial lavage fluid revealed mild neutrophilic inflammation, with no consistent pathogen growth. Response to therapy (corticosteroids, antibiotics, bronchodilators, and diuretics) was poor, and most cats died within days to months. The pathology consisted of interstitial fibrosis with fibroblast/myofibroblast foci, honeycombing with alveolar epithelial metaplasia and type II pneumocyte hyperplasia, and alveolar interstitial smooth-muscle metaplasia. Coincident pulmonary neoplasia was identified in ~25% of the cases.

Cohn LA, Norris CR, Hawkins EC, Dye JA, Johnson CA, Williams KJ. (2004) Identification and characterization of an idiopathic pulmonary fibrosis-like condition in cats. J Vet Intern Med.18(5):632-41.
Williams K, Malarkey D, Cohn L, Patrick D, Dye J, Toews G.(2004) Identification of spontaneous feline idiopathic pulmonary fibrosis: morphology and ultrastructural evidence for a type II pneumocyte defect. Chest 125(6):2278-88