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

Prevalence of respiratory signs in dogs with chronic gastroenteropathy in a referral population in the United Kingdom: 42 cases (2020)

OBJECTIVES

To determine the prevalence of respiratory signs in a referral population of dogs with chronic gastroenteropathy in the United Kingdom, and to describe the epidemiology and clinical presentation of the affected dogs.

MATERIALS AND METHODS

Retrospective review of canine patients diagnosed with chronic gastroenteropathy in a referral centre in the United Kingdom. Data included signalment, gastrointestinal and respiratory signs, blood analysis results and, where present, diagnostic imaging techniques, endoscopy, videofluoroscopic swallow study, bronchoalveolar lavage results and treatment response. To be included, a follow-up of a minimum of 3 months was required. Cases were excluded if there was no minimum diagnostic dataset, the aetiology of the respiratory signs was other than gastrointestinal disease or a non-gastrointestinal systemic disease was the cause of the gastrointestinal signs.

RESULTS

One hundred and forty-eight dogs were included and 42 (28.4%) had concurrent respiratory signs. Gagging (69%) and vomiting (52.4%) were the most common gastrointestinal signs, while coughing (50%), tachypnoea (33.3%) and reverse sneezing (30.9%) were the most common respiratory signs. Abdominal ultrasound was performed in 31 (73.8%) while CT scan was the most common modality for thoracic (62.5%) and head (21.9%) imaging. Endoscopic procedures included gastrointestinal (54.8%), bronchoscopy (19%) and rhinoscopy (23.8%). Dietary modification was the most common treatment (66.67%). Eleven dogs (26.2%) had a relapse of the respiratory signs during the follow-up period, of which, nine (81.8%) had a concurrent relapse of the gastrointestinal signs.

CLINICAL SIGNIFICANCE

Concurrent respiratory signs in dogs with chronic gastroenteropathy are frequent. A clinical improvement of these respiratory signs might be achieved during the therapeutic management of gastrointestinal disorders.

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.

Immune cell composition of the bronchoalveolar lavage fluid in healthy and respiratory diseased dromedary camels

Background

Respiratory diseases are among the most common and expensive to treat diseases in camels with a great economic impact on camel health, welfare, and production. Bronchoalveolar lavage fluid (BALF) has been proven as a valuable sample for investigating the leukocyte populations in the respiratory tract of several species. In the present study, fluorescent antibody labeling and flow cytometry were used to study the immune cell composition of BALF in dromedary camels. Animals with clinical respiratory diseases (n = seven) were compared with apparently healthy animals (n = 10). In addition, blood leukocytes from the same animals were stained in parallel with the same antibodies and analyzed by flow cytometry.

Results

Camel BALF macrophages, granulocytes, monocytes, and lymphocytes were identified based on their forward and side scatter properties. The expression pattern of the cell markers CD172a, CD14, CD163, and MHCII molecules on BALF cells indicates a similar phenotype for camel, bovine, and porcine BALF myeloid cells. The comparison between camels with respiratory disease and healthy camels regarding cellular composition in their BALF revealed a higher total cell count, a higher fraction of granulocytes, and a lower fraction of macrophages in diseased than healthy camels. Within the lymphocyte population, the percentages of helper T cells and B cells were also higher in diseased than healthy camels. The elevated expression of the activation marker CD11a on helper T cells of diseased camels is an indication of the expansion of helper T cells population due to infection and exposure to respiratory pathogens. The higher abundance of MHCII molecules on BALF macrophages from diseased camels indicates a polarization toward an inflammatory macrophage phenotype (M1) in respiratory diseased camels. No significant differences were observed in the systemic leukogram between healthy and diseased animals.

Conclusions

Collectively, the current study represents the first report on flow cytometric analysis of immune cell composition of bronchoalveolar lavage fluid (BALF) in dromedary camels.

Associations between respiratory signs, thoracic CT findings and results of tracheobronchoscopy and bronchoalveolar lavage in dogs

BACKGROUND

Several diagnostic techniques are used in dogs with signs of respiratory disease. The aims of the present study are to estimate the relative sensitivities and associations between the results of diagnostic tests in dogs with respiratory conditions.

METHOD

A retrospective cross-sectional study of dogs referred for investigation of respiratory signs. Associations between clinical signs, thoracic CT findings, tracheobronchoscopic findings, cytology results and bacterial culture results were tested using binary logistic regression.

RESULTS

One hundred and thirty-three dogs were included. Abnormalities were detected by cytology, tracheobronchoscopy, CT and bacterial culture in 91%, 88%, 80% and 25% cases, respectively. There were associations between cough and bronchial lesions on thoracic CT (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.1-6.4, p = 0.037), and between cough and neutrophilic inflammation on cytology (OR 4.5, 95% CI 1.3-15.8, p = 0.020). Bronchial foreign body at bronchoscopy was associated with pulmonary consolidation on CT (OR 8.0, 95% CI 1.6-41.7, p = 0.013) and with positive bacterial culture (OR 10.9, 95% CI 2.1-57.0, p = 0.005). In dogs with normal thoracic CT, abnormalities were detected by cytology, tracheobronchoscopy and bacterial culture in 89%, 77% and 23% cases, respectively.

CONCLUSION

Airway cytology and tracheobronchoscopy provided useful information for diagnosis in many dogs with respiratory signs that had a normal thoracic CT.

Bronchial brush cytology, endobronchial biopsy, and SALSA immunohistochemistry in severe equine asthma

Horses with severe equine asthma (SEA), also known as heaves and recurrent airway obstruction, have persistent neutrophilic inflammation of the lower airways. Cytologic evaluation of bronchoalveolar lavage (BAL) fluid is commonly used to confirm the clinical diagnosis of SEA. However, the utility of microscopic assessment of bronchial brushings, endobronchial biopsies, and immunohistochemical detection of disease-associated biomarkers for the diagnosis of SEA remain poorly characterized. Salivary scavenger and agglutinin (SALSA) has anti-inflammatory properties and downregulated gene expression in SEA; therefore, it was investigated as a tissue biomarker for airway and systemic inflammation. Six asthmatic and 6 non-asthmatic horses were exposed to an inhaled challenge. Before and after challenge, samples of BAL fluid, bronchial brushing, and endobronchial biopsy were collected. Location of SALSA in biopsies was determined, and immunohistochemical label intensity was computed using image analysis software. Serum amyloid A (SAA) was measured to assess systemic inflammation. After challenge, neutrophil proportions were significantly higher in asthmatic versus non-asthmatic horses in BAL fluid (least squares means, 95% confidence interval: 80.9%, 57.2% to 93.1%, vs 3.6%, 1.1% to 10.7%) and in brush cytology slides (39.5%, 7.7% to 83.6%, vs 0.2%, 0% to 2.3%), illustrating the potential of brush cytology as an alternate modality to BAL for assessing intraluminal inflammation. Bronchial histopathologic findings and intensity of SALSA immunolabeling in surface and glandular epithelium were similar in asthmatic and non-asthmatic horses, indicating limited changes in bronchial tissue from the inhaled challenge. Increases in SAA indicated systemic inflammation, but SALSA immunolabeling did not change significantly.

Cytological analysis of tracheal wash and bronchoalveolar lavage fluid in health and respiratory disease in dromedary camels

Background

Tracheal wash (TW) and bronchoalveolar lavage (BAL) have proven to be useful tools for the identification of disease-associated changes in the respiratory tract in human and different animal species. In the dromedary camel, little is known about cytological analysis of TW and BAL in health and disease. The aim of the present study was to evaluate the cytological composition of TW and BAL in health and respiratory disease in dromedary camels.

Methods

TW and BAL samples were collected from dromedary camels and cytological analysis was performed by microscopic examination of prepared smears. Camels with clinical respiratory disease (n = 18) were compared with apparently healthy (control) camels (n = 9).

Results

In the apparently healthy camels, differential cytological analysis of TW samples identified macrophages and neutrophils as the main cell populations with lesser proportions of lymphocytes and epithelial cells and very rare abundance of eosinophils and mast cells. In the TW of camels with respiratory disease, neutrophils were the most abundant cells followed by macrophages and lymphocytes. In the BAL of healthy camels, macrophages represented the main cell type followed by lymphocytes and neutrophils. In respiratory-diseased camels, BAL samples contained higher percentages of neutrophils with reduced percentages of macrophages and lymphocytes in comparison to camels from the control group. Collectively, the results of the current study revealed higher abundance of neutrophils in the TW and BAL from dromedary camels than many other veterinary species. The cytological patterns of TW and BAL from camels with respiratory diseases were characterized by increased proportion of neutrophils and decreased proportion of macrophages in comparison to healthy camels. The proportion of lymphocytes was also decreased in TW samples from diseased camels.

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

BACKGROUND

Canine idiopathic eosinophilic lung disease (ELD) is sparsely documented in the literature.

METHODS

Clinical presentation and outcome of dogs diagnosed with ELD (eosinophilic bronchitis or eosinophilic bronchopneumonia) were reviewed. Subgroups were made based on chronicity of clinical signs and findings of thoracic imaging: NCI (no changes in thoracic imaging), BRON (bronchial/peribronchial pattern), INT (bronchointerstitial/interstitial/alveolar).

RESULTS

Seventy cases were included. There were more young to adult, crossbreed and female dogs. Compared with the other two groups NCI dogs showed lower bronchoalveolar lavage fluid eosinophilic pleocytosis and absence of circulating eosinophilia, bronchiectasis or death due to respiratory disease. All dogs responded clinically to corticosteroids. Median treatment duration was four months. Remission (no clinical signs after treatment discontinuation for >one month) and long-term remission (>six months) was achieved in 60 per cent, and 51 per cent of patients, respectively. Relapse occurred in 26 per cent of cases after remission but was rare (3 per cent) after long-term remission. The one-year, two-year and four-year survival to death due to respiratory disease was 98 per cent, 97 per cent and 91 per cent, respectively.

CONCLUSION

Prognosis and initial clinical response for ELD was generally good although achievement of long-term remission was only seen in 51 per cent of dogs. Different outcomes based on chronicity of signs, corticosteroid dose, thoracic imaging abnormalities and other clinical variables were not appreciated.

Clinical features and radiographic findings in cats with eosinophilic, neutrophilic, and mixed airway inflammation (2011-2018)

Background

Idiopathic inflammatory airway disease (IAD) in cats often is described as asthmatic (eosinophilic) or bronchitic (neutrophilic), but this designation requires collection of airway fluid and it fails to consider cats with mixed airway inflammation.

Objective

To identify clinical features that would differentiate inflammatory disease types.

Animals

Forty‐nine cats with nonspecific airway inflammation identified by bronchoscopic bronchoalveolar lavage (BAL) between 2011 and 2018 were evaluated.

Methods

This is a retrospective study. Cats were categorized by BAL differential cytology as having eosinophilic (eosinophils >20% with neutrophils <14%, or eosinophils >50%), mixed (eosinophils 20%‐50% and neutrophils >14% or discordant inflammation from 2 BAL sites), or neutrophilic (neutrophils >14% and eosinophils <20%) inflammation. Type and duration of presenting complaints, signalment, body condition score, respiratory rate, CBC results, bronchoscopy, BAL results (% recovery, total nucleated cell count, differential cell count), and radiographic findings were compared among groups.

Results

Idiopathic IAD was diagnosed in 49 cats, with BAL eosinophilic inflammation in 23, mixed inflammation in 14, and neutrophilic inflammation in 12. Cough was the predominant presenting complaint with no difference in duration of signs among groups (median, 5.5 months). Respiratory rate and effort also did not differ. Cats with eosinophilic inflammation were significantly younger (4.4 ± 3.3 years) than those with neutrophilic (8.0 ±5.6 years) or mixed inflammation (7.5 ± 4.0 years; P = .03). Results of CBC and interpretation of radiographic findings did not differ among groups.

Conclusions and Clinical Importance

Substantial overlap exists in clinical and radiographic findings in cats with various forms of idiopathic airway inflammation.

Coughing in Small Animal Patients

Cough is one of the most common complaints in human medicine. In veterinary medicine cough is equally frequent and plays a significant role in an owner's perception of their pet's quality of life. In human and veterinary medicine, therapy for chronic cough is often ineffective. The complexity of the cough pathway and species differences have made it difficult to develop an effective antitussive agent for veterinary patients. The few effective antitussive agents currently available are associated with significant adverse effects. Fortunately, several promising drugs currently being studied in human clinical trials may offer options for use of novel antitussive therapies in small animal patients. This article reviews current understanding about cough pathophysiology, diagnostic strategies used to uncover underlying etiology of cough, and examines available options for controlling cough, including novel antitussive therapies used in human medicine.

Quantitative PCR and Cytology of Bronchoalveolar Lavage Fluid in Dogs with Bordetella bronchiseptica Infection

Background

The use of quantitative PCR (qPCR) for detection of Bordetella bronchiseptica in bronchoalveolar lavage fluid (BALF) and demonstration of bacteria adhering to ciliated epithelial cells in BALF or bronchial brushing fluid (BBF) has not been assessed in a series of affected dogs. Coinfections can worsen the clinical severity in bordetellosis, but the specific association with Mycoplasma cynos has not been evaluated.

Objectives

To assess the utility of culture, qPCR and cytologic examination of cytospin preparations in the diagnosis of bordetellosis in dogs and the influence of coinfection by M. cynos on disease severity.

Animals

Twenty‐four referred dogs with B. bronchiseptica infection and 10 healthy dogs.

Methods

Retrospective case series. qPCR (B. bronchiseptica and M. cynos) and culture results from BALF were recorded. Cytospin preparations from BALF and BBF were reviewed. qPCR on BALF from 10 healthy dogs were used as negative control.

Results

The BALF culture and qPCR detected B. bronchiseptica in 14/24 and 18/18 dogs, respectively. Coccobacilli were found adhering to ciliated epithelial cells in 20 of the 21 BALF cytologic preparations where epithelial cells were found, and 2/3 BBF cytologic preparations. Quantitative PCR detected a low level of B. bronchiseptica in one healthy dog. The frequency of detection of M. cynos was not significantly different in B. bronchiseptica (9/17 dogs) compared with healthy dogs (2/10 dogs) (P = .09).

Conclusion and Clinical Importance

Quantitative PCR detection of B. bronchiseptica in BALF appears to be a useful diagnostic tool. Cytologic examination of BALF or BBF, when positive, allows a rapid and reliable diagnosis.

Antimicrobial use Guidelines for Treatment of Respiratory Tract Disease in Dogs and Cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases

Respiratory tract disease can be associated with primary or secondary bacterial infections in dogs and cats and is a common reason for use and potential misuse, improper use, and overuse of antimicrobials. There is a lack of comprehensive treatment guidelines such as those that are available for human medicine. Accordingly, the International Society for Companion Animal Infectious Diseases convened a Working Group of clinical microbiologists, pharmacologists, and internists to share experiences, examine scientific data, review clinical trials, and develop these guidelines to assist veterinarians in making antimicrobial treatment choices for use in the management of bacterial respiratory diseases in dogs and cats.