Cellular composition of bronchial brushings obtained from healthy dogs and dogs with chronic cough and cytologic composition of bronchoalveolar lavage fluid obtained from dogs with chronic cough

Quantifiable features of a tidal breathing phenotype in dogs with severe bronchomalacia diagnosed by bronchoscopy

Dynamic lower airway obstruction is the primary component of canine bronchomalacia, but the ventilatory function remains underinvestigated. This prospective study analyzed tidal breathing characteristics in 28 dogs, comprising 14 with severe bronchomalacia diagnosed by bronchoscopy versus 14 without respiratory disease. Spirometry was conducted in all dogs. Bronchoscopy with bronchoalveolar lavage or brush under anesthesia was performed in 14 dogs with cough and expiratory effort. Severe bronchomalacia was defined by the severity of collapse and total number of bronchi affected. Ventilatory characteristics were compared between groups. Results revealed that dogs with severe bronchomalacia had lower minute volume (218 vs 338 mL/kg, p = .039) and greater expiratory-to-inspiratory time ratio (1.55 vs 1.35, p = .01) compared to control dogs. The tidal breathing pattern of dogs with bronchomalacia was different from that of normal dogs, and the pattern differed from the concave or flat expiratory curves typical of lower airway obstruction. Compared to control dogs, dogs with severe bronchomalacia had a significantly prolonged low-flow expiratory phase (p < .001) on the flow-time plot and a more exponential shape of the expiratory curve (p < .001) on the volume-time plot. Flow-time index ExpLF/Te (>0.14) and volume-time index Vt-AUCexp (≤31%) had a high ROC-AUC (1.00, 95% confidence interval 0.88 to 1.00) in predicting severe bronchomalacia. In conclusion, the tidal breathing pattern identified here indicates abnormal and complicated ventilatory mechanics in dogs with severe bronchomalacia. The role of this pulmonary functional phenotype should be investigated for disease progression and therapeutic monitoring in canine bronchomalacia.

Bronchial collapse and bronchial stenting in 9 dogs

BACKGROUND

Principal and lobar bronchial collapse is increasingly recognized as an isolated entity.

OBJECTIVE

Retrospectively describe the procedure and outcomes of dogs undergoing bronchial stenting at a single referral hospital.

ANIMALS

Nine client-owned dogs with variable degrees of collapse of the left principal bronchus (LPB), lobar bronchus 1 (LB1), and lobar bronchus 2 (LB2), and with clinically relevant signs of respiratory dysfunction.

METHODS

Data were collected from patient records. All dogs underwent stenting of the LPB and LB2. Anatomic and functional impairment grades were assigned to each case before and 4 weeks after stenting. Data regarding response to stenting and complications were evaluated.

RESULTS

Bronchial stenting was considered successful in all cases, with all dogs experiencing improved quality of life (QOL), and decreased functional impairment grade at 4 weeks post-stenting. Follow-up of >6 months was available for 6 dogs and of these, 5 were alive at 12 months, 3 were alive at 18 months, and 1 was alive at 24 months. Stent-related complications occurred in 4 dogs, and were resolvable in 3. Two dogs developed pneumothorax, 1 developed recurrent pneumonia, and 1 developed new-onset coughing. All dogs had mild and manageable coughing post-stenting.

CONCLUSIONS AND CLINICAL IMPORTANCE

Stenting of the LBP and LB2 might be an effective option for dogs with advanced collapse of these bronchi and associated signs. Although all included dogs had resolution or improvement of clinical signs considered life-threatening or as affecting QOL, ongoing coughing is expected. Patient selection appears important with regard to achieving successful outcomes.

Bronchial brushing Xpert improves the diagnostic efficiency of sputum Xpert in patients with pulmonary tuberculosis

BACKGROUND

The role of bronchial brushing Xpert MTB/RIF (hereafter referred to as Xpert) in patients with pulmonary tuberculosis (PTB) remains unclear. Therefore, a retrospective study was conducted aiming to evaluate the diagnostic efficiency of bronchial brushing Xpert in patients with PTB.

METHODS

Between July 2018 and August 2019, suspected PTB patients who were admitted to our hospital and had bronchial brushing and matched sputum collection for acid-fast bacilli (AFB) smear, mycobacterial culture, and Xpert were included for further analysis. Subsequently, PTB was defined based on mycobacterial culture, and if an alternative diagnosis was established, 'non-tuberculosis (TB)' was considered. Comparison of bronchial brushing and matched sputum examination was performed between groups. Then, the differences in the sensitivities between bronchial brushing and sputum Xpert were examined using the chi-square test.

RESULTS

A total of 111 patients were included and divided into TB and non-TB groups (52 versus 59 patients). The sensitivities of Xpert against culture were calculated as follows: sputum, 44.2% (23/52); bronchial brushing, 59.6% (31/52); sputum and bronchial brushing, 69.2% (36/52). The specificities of all Xpert assays were the same (100.0%, 59/59). A significant difference was found in the comparison of the sensitivities of Xpert using sputum, bronchial brushing and both, and the sensitivity of Xpert on both sputum and bronchial brushing was higher than that on sputum alone (p < 0.05). Moreover, it appears that bronchial brushing Xpert was more sensitive than sputum Xpert in the detection of PTB.

CONCLUSION

Bronchial brushing Xpert improves the diagnostic efficiency of sputum Xpert in the detection of PTB.

Single-aliquot, non-bronchoscopic bronchoalveolar lavage in the diagnosis of metastatic mammary tumours in dogs

OBJECTIVE

To evaluate the use of bronchoalveolar lavage as an auxiliary tool for the diagnosis of neoplastic lung metastasis from mammary tumours in dogs.

METHODS

A single-institution prospective observational study including 20 healthy dogs and 30 with mammary tumours. Thoracic radiography and single-aliquot, non-bronchoscopic bronchoalveolar lavage with cytology interpretation was performed in all animals and the results compared between groups.

RESULTS

Dogs with mammary gland tumours and radiographic evidence of pulmonary metastasis had significantly higher relative neutrophil counts in bronchoalveolar lavage fluid than dogs with tumours without evidence of metastasis. In only one dog, in which thoracic radiographs were normal, were malignant cells identified in bronchoalveolar lavage fluid.

CLINICAL SIGNIFICANCE

Inflammatory bronchoalveolar lavage fluid in dogs with mammary gland tumours may suggest metastatic disease. Bronchoalveolar lavage does not appear to be sensitive for identifying malignant cells.

Tracheobronchial brush cytology and bronchoalveolar lavage in dogs and cats with chronic cough: 45 cases (2012-2014)

Background

Animals with chronic cough can have normal bronchoalveolar lavage fluid cytology when small airway disease is absent. Cytology of a tracheobronchial brushing can detect inflammation in larger airways; however, evaluation of this technique has been limited in veterinary medicine.

Objective

To compare airway brush cytology to bronchoalveolar lavage fluid analysis in dogs and cats with chronic cough.

Animals

Forty dogs and five cats undergoing bronchoscopic investigation of chronic cough.

Methods

Prospective study. Bronchoscopy and bronchoalveolar lavage were performed followed by tracheobronchial brushing of central airways. Results of cytologic assessment of BAL fluid and brush cytology were compared for the presence or absence of inflammation and concordance of inflammatory cell type.

Results

Brush cytology detected central airway inflammation in 34 of 40 (85%) dogs with inflammatory BAL fluid. However, the type of inflammation reported differed in 23 of 34 dogs. In five cats with inflammation in BAL fluid, brush cytology detected inflammation in four; the type of inflammation was discordant in all cats.

Conclusions and clinical relevance

Brush cytology has good agreement with BAL regarding the presence of inflammation, although the type of inflammation detected with the different sampling techniques commonly varies. Brush cytology can provide supplementary information to BAL, and additional studies will provide further information on the role of tracheobronchial brush cytology in the diagnosis and management of respiratory conditions.

Transtracheal wash and bronchoalveolar lavage

Examination and sampling of the pulmonary airways can be of great benefit in patients with respiratory disease. Transtracheal and endotracheal washes are minimally invasive procedures that allow for blind sampling of the larger airways for cytologic and culture analysis. Flexible tracheobronchoscopy allows for direct visualization of the trachea, bronchi, and oropharynx. Bronchoalveolar lavage helps to obtain samples from the small airways and alveoli during bronchoscopy. The combined use of these techniques can help clinicians diagnose challenging respiratory cases. The following article reviews the indications and techniques of these procedures.

Airway evaluation and flexible endoscopic procedures in dogs and cats: laryngoscopy, transtracheal wash, tracheobronchoscopy, and bronchoalveolar lavage

Flexible endoscopy is a valuable diagnostic approach to the upper and lower respiratory tract, because it allows direct visualization and sample collection. Techniques requiring a range of specialized equipment and varying levels of experience have been developed to access and evaluate each anatomic region. Familiarity with appropriate indications for each procedure and normal appearance, cytology, and culture results from each region will enhance diagnostic success.

Trace and major elements status in bronchoalveolar lavage fluid in dogs with or without bronchopneumonia

The aim of this study was to investigate the relationships between the bronchopneumonia and mean concentrations of those trace elements in bronchoalveolar lavage fluid (BALF). Twenty-nine dogs were included this study (17 healthy dogs and 12 dogs with respiratory disease). Each BALF sample had been obtained during bronchoscope examination by use of a standardized method. The concentrations of Al, Br, Ca, Cu, Fe, K, Ni, P, Si, Sr and Zn in BALF were measured by the particle-induced X-ray emission method. We found no relationship between the bronchopneumonia and the levels of elements in the BALF, except Ca, P and Zn. The dogs with respiratory disease were found to have a large amount of Ca and Zn, and a high Ca/P and Zn/Cu ratios in BALF compared to those without respiratory disease.

Quantification of mucin gene expression in tracheobronchial epithelium of healthy dogs and dogs with chronic bronchitis

OBJECTIVE

To develop a real-time PCR assay for the quantification of mucin gene expression in tracheobronchial brushing specimens from dogs and compare mucin gene expression in specimens from dogs with naturally occurring chronic bronchitis with that in specimens from healthy dogs.

ANIMALS

7 healthy dogs and 5 dogs with chronic bronchitis.

PROCEDURES

Primers that were designed to span the predicted intron-exon boundaries of a canine MUC5AC-like gene were used to develop a real-time PCR assay for quantification of expression of that gene. Total mRNA was isolated from tracheobronchial brushing specimens obtained from dogs with and without bronchitis during anesthesia; MUC5AC-like gene expression in those samples was quantified by use of the real-time PCR assay.

RESULTS

The PCR assay was sensitive and specific for the target sequence, the predicted amino acid sequence of which had greatest homology with human, porcine, and rat MUC5AC. The assay was able to quantify the target over a wide dynamic range. Dogs with chronic bronchitis had a 3.0-fold increase in the quantity of MUC5AC-like mRNA, compared with healthy dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

The ability to measure mucin gene expression from tracheobronchial brushing specimens collected from client-owned dogs during routine bronchoscopy should prove to be a useful tool for the study of bronchitis in dogs and expand the usefulness of airway inflammation in dogs as a model for bronchitis in humans.