Reflux aspiration in lungs of dogs with respiratory disease and in healthy West Highland White Terriers

Abstract

BackgroundGastroesophageal reflux and microaspiration (MA) of gastric juice are associated with various human respiratory diseases but not in dogs.ObjectiveTo detect the presence of bile acids in bronchoalveolar lavage fluid (BALF) of dogs with various respiratory diseases.AnimalsTwenty‐seven West Highland White Terriers (WHWTs) with canine idiopathic pulmonary fibrosis (CIPF), 11 dogs with bacterial pneumonia (BP), 13 with chronic bronchitis (CB), 9 with eosinophilic bronchopneumopathy (EBP), 19 with laryngeal dysfunction (LD), 8 Irish Wolfhounds (IWHs) with previous BPs, 13 healthy WHWTs, all privately owned dogs, and 6 healthy research colony BeaglesMethodsProspective cross‐sectional observational study with convenience sampling of dogs. Bile acids were measured by mass spectrometry in BALF samples. Total bile acid (TBA) concentration was calculated as a sum of 17 different bile acids.ResultsConcentrations of TBA were above the limit of quantification in 78% of CIPF, 45% of BP, 62% of CB, 44% of EBP, 68% of LD, and 13% of IWH dogs. In healthy dogs, bile acids were detected less commonly in Beagles (0/6) than in healthy WHWTs (10/13). Concentrations of TBA were significantly higher in CIPF (median 0.013 μM, range not quantifiable [n.q.]‐0.14 μM, P < .001), healthy WHWTs (0.0052 μM, n.q.‐1.2 μM, P = .003), LD (0.010 μM, n.q.‐2.3 μM, P = .015), and CB (0.0078 μM, n.q.‐0.073 μM, P = .018) groups compared to Beagles (0 μM, n.q.).Conclusion and Clinical ImportanceThese results suggest that MA occurs in various respiratory diseases of dogs and also in healthy WHWTs.

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

“…Aspiration injury was found in dogs with both neutrophilic and lymphocytic inflammation as well as solely lymphocytic inflammation in BAL fluid. Aspiration injury is thought to trigger a Th17 response as part of the immune response to inhalation of pathogens or irritant material, and microaspiration has been proposed to play an important role in a number of respiratory diseases in dogs . In children, both strongly and weakly acidic chemical insults resulted in increased BAL fluid neutrophils and increased lymphocytes, indicating a nonspecific response to airway injury .…”

“…Aspiration injury is thought to trigger a Th17 response as part of the immune response to inhalation of pathogens or irritant material, 29 and microaspiration has been proposed to play an important role in a number of respiratory diseases in dogs. 30,31 In children, both strongly and weakly acidic chemical insults resulted in increased BAL fluid neutrophils and increased lymphocytes, indicating a nonspecific response to airway injury. 32 It is unclear why some dogs in our study developed mixed inflammation rather than purely lymphocytic inflammation, but it might reflect a disease process more similar to aspiration pneumonitis in some dogs versus the neutrophilic response of aspiration pneumonia in other dogs.…”

Assessment of the lung microbiota in dogs: influence of the type of breed, living conditions and canine idiopathic pulmonary fibrosis

“…These bacteria preferentially contaminate food (Brochothrix [28]) and water (Curvibacter [29], Rhodoluna [30], Limnohabitans [31], and Flavobacteriaceae_genus [32]), and can be ingested by dogs. Their presence in the LM of WHWTs could be associated with the higher abundance of gastroesophageal reflux reported in that breed compared with other breeds [33]. The higher rate of gastroesophageal reflux in WHWTs has been hypothesized to play a role in the onset and/or in the progression of CIPF [33].…”

“…Their presence in the LM of WHWTs could be associated with the higher abundance of gastroesophageal reflux reported in that breed compared with other breeds [33]. The higher rate of gastroesophageal reflux in WHWTs has been hypothesized to play a role in the onset and/or in the progression of CIPF [33]. In man, gastroesophageal reflux is associated with IPF although the role of these exposures in the pathogenesis of IPF is still only hypothetical [34].…”

Idiopathic pulmonary fibrosis in West Highland white terriers: An update

“…In CIPF, the possible role of gastroesophageal reflux and microaspiration of small amounts of gastric content was evaluated by measuring total bile acids in BALF by mass spectrometry in healthy WHWTs and WHWTs with CIPF, in comparison with BALF from dogs with other diseases (Maatta et al, 2018). Bile acids were detected more frequently in healthy WHWTs, compared with dogs of other breeds and were at higher concentrations in WHWTs with CIPF than in healthy WHWTs, suggesting that micro-aspiration could be associated with the predisposition of WHWT to CIPF.…”