Eosinophilic bronchitis, eosinophilic granuloma, and eosinophilic bronchopneumopathy in 75 dogs (2006‐2016)

Abstract

Background Eosinophilic lung disease is a poorly understood inflammatory airway disease that results in substantial morbidity. Objective To describe clinical findings in dogs with eosinophilic lung disease defined on the basis of radiographic, bronchoscopic, and bronchoalveolar lavage fluid (BAL) analysis. Categories included eosinophilic bronchitis (EB), eosinophilic granuloma (EG), and eosinophilic bronchopneumopathy (EBP). Animals Seventy‐five client owned dogs. Methods Medical records were retrospectively reviewed for dogs with idiopathic BAL fluid eosinophilia. Information abstracted included duration and nature of clinical signs, bronchoscopic findings, and laboratory data. Thoracic radiographs were evaluated for the pattern of infiltrate, bronchiectasis, and lymphadenomegaly. Results Thoracic radiographs were normal or demonstrated a bronchial pattern in 31 dogs assigned a diagnosis of EB. Nine dogs had intraluminal mass lesions and were bronchoscopically diagnosed with EG. The remaining 35 dogs were categorized as having EBP based on radiographic changes, yellow green mucus in the airways, mucosal changes, and airway collapse. Age and duration of cough did not differ among groups. Dogs with EB were less likely to have bronchiectasis or peripheral eosinophilia, had lower total nucleated cell count in BAL fluid, and lower percentage of eosinophils in BAL fluid compared to dogs in the other 2 groups. In contrast to previous reports, prolonged survival (>55 months) was documented in dogs with EG. Conclusions and Clinical Importance Dogs with eosinophilic lung disease can be categorized based on imaging, bronchoscopic and BAL fluid cytologic findings. Further studies are needed to establish response to treatment in these groups.

Clinical features and long‐term follow‐up of 70 cases of canine idiopathic eosinophilic lung disease

“…Consistent with this perception one of the two patients in the present population who succumbed to their respiratory disease had a diagnosis of EPG. A recent study15 suggested a more favourable prognosis for dogs with EPG. However, the diagnosis of EPG in dogs in this study was based on a different diagnostic criteria to the usual historical EPG definition of parenchymal lung disease and pulmonary granulomas (consolidation or masses) characterised, when histopathology is performed, by a large population of eosinophils usually with macrophages and epithelioid cells 19–22.…”

“…As the BRON group was the one where CT was used less frequently (37 per cent) it is possible that at least some of these dogs would have shown interstitial changes on CT and indeed belonged to the INT group. A recent paper15 also attempted to separate ELD into EB and EBP. In this paper however, the definitive criteria to separate both processes were the severity of bronchoscopy findings and dogs could be classified as EB or EBP with a bronchial radiographic pattern: EB had milder bronchoscopic findings and EBP more severe ones.…”

“…EBP and EB are categorised as separate processes in the human classification,1 3 11 but most of the previous retrospective studies of canine idiopathic ELD have described the disease as EBP and have combined cases with primarily bronchial, peribronchial or parenchymal disease into one population. What constitutes EB, as a different entity to EBP, has not been historically well described in canine medicine,1 2 9 10 12–14 but a recent retrospective study reported the clinical presentation and findings of dogs with ELD with a presumptive diagnosis of EB or EBP based on the severity of their bronchoscopy findings 15. Studies separating canine ELD cases primarily by their thoracic imaging characteristics have not been reported.…”

“…What constitutes EB, as a diferent entity to EBP, has not been historically well described in canine medicine, 1 2 9 10 12-14 but a recent retrospective study reported the clinical presentation and indings of dogs with ELD with a presumptive diagnosis of EB or EBP based on the severity of their bronchoscopy indings. 15 Studies separating canine ELD cases primarily by their thoracic imaging characteristics have not been reported.…”

Bronchoalveolar lavage fluid lymphocytosis in 104 dogs (2006‐2016)

“…In humans with hypersensitivity pneumonitis, BAL fluid lymphocytosis was always present in the acute phase of disease (first 3‐8 weeks) although not always later in the course of disease. In a separate study of eosinophilic lung disease in 86 dogs, encompassing the same time frame as our study, BAL fluid lymphocytosis >20% was present in only 5 of 86 dogs . It is possible that lymphocytes are present only in the early stage of hypersensitivity‐type lung disease in dogs and decrease with chronicity, although this possibility was not examined specifically here.…”