Objectives Feline asthma (FA) and feline chronic bronchitis (CB) are common respiratory conditions in cats, frequently referred to as ‘feline lower airway disease’. However, the aetiologies of both inflammatory airway diseases are probably different. Little is known about the differences in signalment, clinical signs, laboratory abnormalities and radiographic features between cats with these two airway diseases. The aim of the study was to investigate whether certain parameters can help in differentiating between both diseases, as distinguished by airway cytology. Methods Seventy-three cats with FA and 24 cats with CB were included in the retrospective study. Inclusion criteria were compatible clinical signs and a cytological evaluation of bronchoalveolar lavage fluid indicating either FA (eosinophilic inflammation) or CB (neutrophilic inflammation) without cytological or microbiological evidence of bacterial infection. Parameters of signalment, physical examination, haematology and thoracic radiographs of both disease groups were compared statistically ( P <0.05). Results The median age of cats with FA was 6 years, and was 7.5 years in cats with CB ( P = 0.640). The most commonly reported clinical signs in both groups were a cough (95% FA/96% CB; P = 1.000), pathological pulmonary auscultatory sounds (82% FA/79% CB; P = 0.766) and dyspnoea (73% FA/79% CB; P = 0.601). Abnormal radiographic lung patterns were detected in 94% of cats with FA and 91% with CB ( P = 0.629), respectively. Blood eosinophilia was significantly more common in cats with FA (40%) compared with CB (27%) ( P = 0.026). Conclusions and relevance The study indicates that a differentiation of FA and CB by means of signalment, a single clinical sign, and haematological and radiographic findings is not possible.

ZusammenfassungFelines Asthma und feline chronische Bronchitis gelten als die häufigsten chronischen Erkrankungen der unteren Atemwege bei Katzen und werden oft als chronische Bronchialerkrankungen zusammengefasst. Beim felinen Asthma wird ursächlich eine Hypersensitivitätsreaktion Typ I vermutet, bei der chronischen Bronchitis ist die Ätiologie noch weitgehend unbekannt. Betroffene Katzen können Husten, Dyspnoe und Atemgeräusche zeigen. Beide Krankheitsbilder werden zurzeit anhand des zytologischen Zellbildes einer durch Bronchoalveolarlavage gewonnenen Probe definiert und können sich in Ursache, Behandlung und klinischem Verlauf unterscheiden. Die Diagnosestellung beinhaltet den Ausschluss anderer Grunderkrankungen in Kombination mit dem Nachweis einer nicht infektiösen, eosinophilen oder neutrophilen Entzündung der Atemwege. Neben der etablierten Therapie mit oral oder inhalativ applizierten Glukokortikoiden und Bronchodilatatoren werden in dem Artikel auch neuere therapeutische und diagnostische Ansätze vorgestellt.

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Objective Feline asthma (FA) and chronic bronchitis (CB) are common inflammatory diseases of the bronchial tree in cats. Even though both conditions are characterized by infiltration with different types of inflammatory cells, therapeutic measures are often similar. Little is known about potential differences in therapeutic management of these 2 airway diseases. Therefore, aim of the study was to compare initial and long-term treatment, therapeutic success, side effects, and owner satisfaction between cat with FA and those with CB. Material and methods Thirty-five cats with FA and 11 cats with CB were included in the retrospective cross-sectional study. Inclusion criteria were compatible clinical and radiographic signs and cytological evidence of eosinophilic inflammation (FA) or sterile neutrophilic inflammation (CB) in bronchoalveolar-lavage fluid (BALF). Cats with CB were excluded if evidence of pathological bacteria was present. Owners were contacted to fill out a standardized questionnaire on therapeutic management and response to treatment. Results Comparing treatment in both groups, no statistical significance was detected. Most cats were initially treated with corticosteroids as oral (FA 63%/CB 64%, P=1), inhaled (FA 34%/CB 55%, P=0.296) or injected formulations (FA 20%/CB 0%, P=0.171). In addition, oral bronchodilators (FA 43%/CB 45%, P=1), and antibiotics were given in some cases (FA 20%/CB 27%, P=0.682). For long-term management, 43% of cats with FA and 36% of cats with CB received inhaled corticosteroids (P=1), oral corticosteroids (FA 17%/CB 36%, P=0.220), and oral bronchodilators (FA 6%/CB 27%, P=0.084) as well as courses of antibiotics (FA 6%/CB 18%, P=0.238). Treatment-related side effects (polyuria/polydipsia, facial fungal infection, and diabetes mellitus) were reported in 4 cats with FA and 2 cats with CB. The majority of owners stated to be extremely or very satisfied with the response to treatment (FA 57%/CB 64%, P=1). Conclusion Significant differences regarding management and response to therapy for both diseases could not be detected. Clinical relevance Based on owner survey, chronic bronchial diseases as feline asthma and chronic bronchitis could be managed successfully with similar treatment.