Comparison of tracheal aspirates before and after high-speed treadmill exercise in racehorses

OBJECTIVE: To determine whether percentages of neutrophils in tracheal aspirate (TA) samples collected from racehorses are increased after exercise and whether interpretation of results from TA samples taken before and after exercise agree. DESIGN: Case series of 40 young Thoroughbred and Standardbred racehorses in race training presented for evaluation of poor performance. PROCEDURE: TA samples were collected endoscopically from racehorses presented for poor performance 24 h before and 1 to 2 h after high speed treadmill exercise testing. Aliquots of the retrieved fluid were cytocentrifuged and smears were stained with Diff-Quik. Mean neutrophil counts were expressed as percentages of the total number of inflammatory cells counted and subsequently were categorised as either above or below an accepted cut-off of 20%. Comparisons between percentages of neutrophils before and after exercise were made. RESULTS: Percentage of neutrophils from TA samples obtained from racehorses after exercise was significantly higher than neutrophil percentages from TA samples collected from the same horse before exercise. In horses with TA specimens that were categorised as having < or = 20% neutrophils before treadmill exercise, the percentage of neutrophils in their TA specimens after exercise was, on average, significantly higher and was greater than the cut-off value of 20%. CONCLUSION: Recent strenuous exercise may change the proportion of neutrophils in lower airways of racehorses and practitioners should be aware of this when collecting and interpreting the results from TA samples. The most practical time for collection of a TA sample to obtain the most diagnostically useful information might be after a suitable washout period of at least 1 to 2 h post-exercise.     

Bronchoalveolar lavage cytology from captive badgers

Background: Bronchoalveolar lavage (BAL) fluid is evaluated for the diagnosis and study of lung disease and airway inflammation. Cytologic profiles for BAL fluid have not been reported for badgers and may be useful in understanding the pathogenesis of pulmonary diseases such as Mycobacterium bovis. Objective: The aim of this study was to evaluate cytologic and microbial findings in BAL fluid from captive European badgers (Meles meles) and identify correlates with the results of concurrently collected blood and fecal samples. Methods: BAL fluid (by a nonbronchoscopic method) and jugular venous blood samples (for routine CBC) were obtained from 23 captive tuberculosis‐free anesthetized badgers on 2 occasions 4 weeks apart. Fecal samples were collected for routine parasitology. Morphologic evaluation and 100‐cell differentials were done on cytocentrifuged BAL specimens. Pellets from centrifuged BAL were aerobically cultured for bacteria. Results: With the 2 BAL samples from each of the 23 badgers combined, the median (range) cell percentages were 73.0% (5–95%) neutrophils, 7.5% (2–16%) macrophages, 8.0% (0–27%) lymphocytes, and 9.5% (0–92%) eosinophils. Macrophages frequently contained silica‐like crystals. Other findings included ciliated epithelial cells, goblet cells, mucus, and Aelurostrongylus sp. larvae. A light growth of Streptococcus, Pasteurella, or Escherichia coli was cultured in 6 badgers. Trypanosoma pestanai were identified in blood from 10 badgers and fecal parasites (mainly coccidia) were found in 20 badgers. No correlation was found between BAL and CBC results and the presence of parasites. Conclusions: The predominance of neutrophils in BAL fluid from badgers differs from the predominance of macrophages found in BAL from other species. This difference may reflect the burrowing lifestyle or the unique immune response of badgers.     

Comparison of tracheal aspirates and bronchoalveolar lavage in racehorses. 1. Evaluation of cytological stains and the percentage of mast cells and eosinophils

OBJECTIVE: To compare a fast Romanowsky cytological stain (Diff-Quik) and Leishman's stain for the detection of mast cells in samples from the lower airways of racehorses, and to compare the proportion of mast cells and eosinophils in the total inflammatory cells in tracheal aspirate (TA) with those in paired bronchoalveolar lavage (BAL) samples. DESIGN: Retrospective case series of 48 young Thoroughbred and Standardbred racehorses. PROCEDURE: Fifty-one paired TA and BAL samples were collected after treadmill exercise from 48 horses with poor racing performance. Two slides were prepared from each sample; one was stained with Diff-Quik stain and the other with Leishman's stain. Differential cell counts of eosinophils and mast cells were recorded from each slide. Comparison of the suitability of the stains for the detection of mast cells, and comparisons of eosinophil and mast cell percentages in TA and BAL samples were analysed using the non-parametric Wilcoxon matched pairs test. RESULTS: Percentages of mast cells were significantly higher in Leishman than in Diff-Quik stained slides in both TA (P = 0.03) and BAL samples (P < 0.0001). Mast cell percentages were significantly higher in BAL than in TA samples using Leishman's stain (P < 0.0001). There was no significant difference in eosinophil percentages between TA and BAL samples (P = 0.07). CONCLUSIONS: Fast Romanowsky type stains (for example Diff-Quik) are not appropriate for the detection of mast cells in samples from the equine lower respiratory tract. Therefore, a metachromatic stain that reliably identifies mast cells (for example Leishman's) should be used if evaluation of mast cells in lower respiratory tract is undertaken. Mast cells are predominantly found in the distal small airways and alveoli sampled with a BAL. In contrast, eosinophils appear to be evenly distributed in the lower respiratory tract. However, high percentages of eosinophils are occasionally found only in TA samples. We recommend that both a TA and BAL be used for the evaluation of eosinophils and mast cells within the equine lower respiratory tract.     

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

OBJECTIVE: To determine whether bronchial brushings from dogs with chronic cough have increased numbers of goblet cells and WBCs, compared with numbers for healthy dogs, or have differing WBC populations, compared with populations in bronchoalveolar lavage (BAL) fluid obtained from dogs with chronic cough. ANIMALS: 9 healthy dogs and 10 dogs with chronic cough. PROCEDURE: Specimens were collected by use of bronchoscopy. Cellular composition was determined for brushings, and results from dogs with chronic cough were compared with those from healthy dogs. Cellular composition of brushings was compared with composition of BAL obtained from dogs with chronic cough. RESULTS: Brushings from healthy dogs contained a median of 2.9 x 10(6) epithelial cells, comprising 100% epithelial cells (96% ciliated, 3% goblet, and 1% other) and no WBCs. Brushings from dogs with chronic cough had 4.5 x 10(6) epithelial cells, comprising 93% epithelial cells (86% ciliated, 2% goblet, and 12% other). Dogs with chronic cough had significantly greater percentages of WBCs (7%) and neutrophils (6%), compared with values for healthy dogs. Five dogs with chronic cough had no neutrophilic inflammation evident in BAL, but 4 of these had evidence of neutrophilic inflammation in brushings. CONCLUSIONS AND CLINICAL RELEVANCE: Neutrophils, but not goblet cells, were increased in brushings from dogs with chronic cough. Analysis of bronchial brushings provides information about airway inflammation that differs from that found by examination of BAL in some dogs with chronic cough and is a more sensitive indicator of airway inflammation than cytologic examination of BAL in these dogs.     

Effects of collecting serial tracheal aspirate and bronchoalveolar lavage samples on the cytological findings of subsequent fluid samples in healthy Standardbred horses

Objective To evaluate the effect of collecting serial tracheal aspirate (TA) and bronchoalveolar lavage (BAL) samples on the cytological findings of subsequent fluid samples obtained from horses without clinical signs of respiratory disease. Study design Experimental. Study population Six healthy Standardbred horses. Methods Endoscopically‐guided TA samples, and BAL samples collected using the blind field technique were obtained from the six horses on days 1, 2, 3, 4, 5, 12, and 17. On day 17, horses were sampled three times: at baseline and at 2.5 h and 4 h apart. The differential cytology of the fluid samples collected at each time point was expressed as percentages and compared statistically. Results There was a significant increase in neutrophil percentage in the TA samples taken at day 17 (at 2.5 h but not at 4 h apart). There was no significant change in the neutrophil percentages in the TA samples when repeated samples were taken ≥24 h apart. There was no significant change in the neutrophil percentages in the BAL fluid at any collection point. There were inconsistent changes in the percentages of lymphocytes and macrophages in the BAL fluid over time, but these remained within normal reference ranges and were considered clinically insignificant. Conclusions Serial TA and BAL samples can be taken at 24 h intervals without affecting the cytological findings of subsequent fluid samples collected using the techniques described.     

Comparison of bronchoalveolar lavage and respiratory secretion cytology in horses with histologically diagnosed pulmonary disease

Equine bronchoalveolar lavage (BAL) fluid collected from 70 horses and respiratory secretions (RS) obtained from 61 of these horses were evaluated cytologically and grouped according to the histological diagnosis of the lungs from which they were obtained. The histological categories included: normal lung (8 horses); pulmonary eosinophilic infiltration (9 horses); interstitial pneumonia (5 horses); pulmonary hemorrhage (5 horses); and mild (12 horses), moderate (7 horses) and severe (24 horses) chronic small airway disease. In horses with pulmonary disease, all BAL samples and all but one RS sample differed cytologically to those obtained from normal horses; however, the type and severity of the pulmonary disease could not always be determined using either BAL or RS cytology. There was a positive association between the percentage of neutrophils in BAL and the neutrophil scores in RS specimens; there was no positive association between other cell types.     

Evaluation of a risk-screening questionnaire to detect equine lung inflammation: results of a large field study

Reasons for performing study: The diagnosis of equine recurrent airway obstruction (RAO) and inflammatory airway disease (IAD) is based on clinical signs and increased inflammatory cell percentages in the bronchoalveolar lavage (BAL) fluid. Since a BAL is an invasive procedure, a risk‐screening questionnaire (RSQ) would be a valuable screening tool for lung inflammation. Objective: To evaluate the accuracy of a RSQ to detect lower airway inflammation (LAI) in a large population of horses. Methods: A standardised BAL was performed in the field on 167 horses in Alberta, Canada. Horses were separated into 3 categories: 1) BAL normal; 2) BAL mild to moderate LAI (MLAI), and 3) BAL severe LAI (SLAI). The horse owners were asked to complete a RSQ. The RSQ scores were compared to the BAL results to determine the likelihood of a horse having MLAI, SLAI or no LAI. Results: Based on BAL cytology, 28 (17%) horses were normal and 139 (83%) were abnormal, with 110 (66%) showing MLAI and 29 (17%) SLAI. Horses with SLAI and MLAI had a mean RSQ score of 0.95 and 0.70, respectively, compared to 0.60 for normal BAL horses. Horses with SLAI showed more clinical signs than normal and MLAI horses. The sensitivity and negative predictive values of the RSQ for detecting SLAI using a cut‐off score of 0.87, were excellent at 0.90 (95%CI 0.73–0.98) and 0.96 (95%CI 0.82–1.00). Questions on the clinical signs typically found in RAO cases differed significantly between horses with BAL SLAI and those with BAL normal. Conclusions: Prevalence of MLAI was high in this population. Although the RSQ did not allow differentiating normal horses from horses with MLAI, it has a high sensitivity to detect horses with SLAI and is therefore a good screening tool for SLAI.     

Airway inflammation in Michigan pleasure horses: prevalence and risk factors

REASONS FOR PERFORMING STUDY: Although subclinical airway inflammation is thought to be common in horses, there is little information on its prevalence and none on risk factors. OBJECTIVE: To determine the prevalence and risk factors for an increased number of inflammatory cells and for mucus accumulation in the trachea of pleasure horses. METHODS: Horses (n = 266) in stables (n = 21) in Michigan were examined endoscopically, once in winter and once in summer 2004. Visible tracheal mucoid secretions were graded 0-5 and inflammatory cell numbers counted in a tracheal lavage sample. Information collected about each horse included age, gender, presence of cough, percent time indoors and source of roughage. The repeated measures were analysed by generalised estimating equations and linear mixed models. RESULTS: Horses eating hay, especially from round bales, had the most neutrophils, whereas horses feeding from pasture had the fewest. Being female and being outdoors in winter were associated with increased numbers of inflammatory cells. Older horses had fewer macrophages than young horses. More than 70% of horses had >20% neutrophils in tracheal lavage. Twenty percent of horses had a mucus accumulation score >1; 17% had both a mucus score >1 and >20% neutrophils. The significant risk factors for mucus accumulation >1 were age >15 years, feeding on hay as compared to pasture, and being outdoors for more than 80% time in winter. Even though mucus accumulation score >1 was a risk factor for cough, only half of such horses coughed. Cough and mucus accumulation were associated with increased number of neutrophils. CONCLUSIONS: In comparison to pasture feeding, hay feeding, particularly from round bales, was associated with an increased number of neutrophils in the airway. Being outdoors in winter was associated with increased numbers of inflammatory cells and with mucus accumulation. Because 70% of horses have >20% neutrophils, this value should not be used as the sole indicator of airway inflammation. POTENTIAL RELEVANCE: The study reinforces the importance of hay feeding and older age as risk factors for inflammatory airway disease. Horses that do not have 'heaves' may be best kept indoors when winters are cold.     

Clinical signs, evaluation of bronchoalveolar lavage fluid, and assessment of pulmonary function in horses with inflammatory respiratory disease

OBJECTIVE: To evaluate the association among clinical signs, results of cytologic evaluation of bronchoalveolar lavage (BAL) fluid, and measures of pulmonary function in horses with inflammatory respiratory disease. ANIMALS: 9 healthy horses, 5 horses with inflammatory airway disease (IAD), and 9 horses with chronic obstructive pulmonary disease (COPD). PROCEDURES: Clinical examination, lung function tests, and BAL were performed on each horse. RESULTS: Standard lung mechanics of horses with exacerbated COPD differed significantly from those of healthy horses; however, there were few differences among horses with IAD, horses with COPD during remission, and healthy horses. Most variables for forced expiration (FE) in horses with COPD or IAD differed significantly from those for healthy horses. Results of clinical examination had low to moderate sensitivity and predictive values for a diagnosis of COPD (range, 67 to 80%). Results of FE tests had high sensitivity, specificity, and predictive values for a diagnosis of COPD (79 to 100%), and results of standard lung mechanics tests had low sensitivity and predictive values (22 to 69%). Percentage of neutrophils in BAL fluid was highly sensitive (100%) but moderately specific (64%) for a diagnosis of COPD. CONCLUSIONS AND CLINICAL RELEVANCE: Clinical examination is moderately accurate for establishing a diagnosis of COPD. Forced expiration tests can specifically detect early signs of airway obstruction in horses with COPD and IAD that may otherwise be inapparent. Cytologic evaluation of BAL fluid allows early detection of inflammatory respiratory disease, but it is not specific for COPD.     

What's in a name? Inflammatory airway disease in racehorses in training

The term 'inflammatory airway disease' (IAD) is often used to describe the syndrome of lower airway inflammation that frequently affects young racehorses in training around the world. In practice, this inflammation is generally diagnosed using a combination of endoscopic tracheal examination, including grading of amounts of mucus present and tracheal wash sampling. However, a recent consensus statement from the American College of Veterinary Internal Medicine concluded that bronchoalveolar lavage (BAL) sampling, rather than tracheal wash (TW) sampling, is required for cytological diagnosis of IAD and that tracheal mucus is not an essential criterion. However, as BAL is a relatively invasive procedure that is not commonly used on racing yards, this definition can only be applied routinely to a biased referral population. In contrast, many practitioners continue to diagnose IAD using endoscopic tracheal examination and sampling. We argue that, rather than restricting the use of the term IAD to phenotypes diagnosed by BAL, it is important to distinguish in the literature between airway inflammation diagnosed by BAL and that identified in the field using TW sampling. We suggest the use of the term brIAD for the former and trIAD for the latter. It is essential that we continue to endeavour to improve our understanding of the aetiology, pathogenesis and clinical relevance of airway inflammation identified in racehorses in training using tracheal examination and sampling. Future studies should focus on investigations of the component signs of airway inflammation.     

Bronchoalveolar lavage cytology and hematology: a comparison between high and low health status pigs at three different ages.

Bronchoalveolar lavages (BALs) were performed with a bronchoscope on 5- and 7.5-week-old, anesthetized, high health status pigs (n = 14). At 10 weeks of age, pigs (n = 28) were necropsied, lungs were removed, and BAL samples were collected from the right diaphragmatic lobe with a modified 12-Fr (4-mm) Foley catheter. Peripheral blood was sampled from all pigs (n = 28) before each BAL procedure. Peripheral blood and BAL samples were collected according to a similar study design at 5, 7.5, and 10 weeks of age from 12 low health status pigs, which were raised according to standard farm procedures (n = 6) or as segregated early weaned pigs (n = 6). Bronchoalveolar lavage cytology and hematologic 95% confidence intervals were determined for 5-, 7.5-, and 10-week-old high (group A) and low health status pigs (groups B and C). The results were compared between the different groups. Repeated BALs were easily performed in all pigs, making this an additional tool for evaluation of respiratory health. Total numbers of cells and neutrophils in peripheral blood and BAL samples were greater in low health status pigs than in high health status pigs. Hematologic results paralleled the findings in BAL fluid. Segregated early weaning of low health status pigs in a less challenging environment mainly reduced the number of neutrophils in BAL samples and peripheral blood.     

Inhaled fluticasone reduces bronchial responsiveness and airway inflammation in cats with mild chronic bronchitis

This study investigated the effect of inhaled fluticasone on lower airway inflammation and bronchial responsiveness (BR) to inhaled carbachol in cats with very mild, chronic bronchitis (n = 5) that were compared with healthy cats serving as controls (n = 6). Chest radiographs, BR tests performed non-invasively by barometric whole body plethysmography (BWBP) and bronchoalveolar lavage (BAL) were performed before and after treatment. BR was quantified by calculating the concentration of carbachol inducing bronchoconstriction (C-Penh300%), defined as a 300% increase of baseline Penh, an index of bronchoconstriction obtained by BWBP. BAL fluid was analyzed cytologically and the oxidant marker 8-iso-PGF2alpha was determined. At test 1, healthy cats and cats with bronchitis were untreated, whereas for test 2 inhalant fluticasone (250 microg once daily) was administrated for 2 consecutive weeks to cats with bronchitis. Control cats remained untreated. Inhaled fluticasone induced a significant increase in C-Penh300% and a significant decrease of BAL fluid total cells, macrophages, neutrophils and 8-iso-PGF2alpha in cats with bronchitis, whilst untreated control cats did not show significant changes over time. This study shows that a 2-week fluticasone treatment significantly reduced lower airway inflammation in very mild bronchitis. BR could be successfully monitored in cats using BWPB and decreased significantly in response to inhaled fluticasone. 8-Iso-PGF2alpha in BAL fluid was responsive to treatment and appeared as a sensitive biomarker of lower airway inflammation in cats.     

Bronchoalveolar lavage fluid in Standardbred racehorses: Influence of unilateral/bilateral profiles and cut-off values on lower airway disease diagnosis

The aim of this study was to determine whether the lung side being sampled would significantly influence bronchoalveolar lavage (BAL) cytological profiles and subsequent diagnosis in Standardbred racehorses. One hundred and thirty-eight French Trotters in active training and racing were included in a prospective observational study. BAL was performed using videoendoscopy in both right and left lungs during summer meetings in 2011 (64 horses) and 2012 (74 horses). Cytological data performed 24 h later from right and left lungs were compared and specifically used to classify horses as affected with exercise-induced pulmonary haemorrhage (EIPH), inflammatory airway disease (IAD), or were ‘controls’. For IAD, cytological definition was based on two different cut off values.Neutrophil percentages, haemosiderophage percentages and the haemosiderophage/macrophage (H/M) ratios were significantly higher in the right compared to the left lung. Measures of intra-class correlation coefficients revealed a fair agreement between left and right lungs for percentages of mast cells, eosinophils, and for the H/M ratio, and a moderate agreement for neutrophil percentages. Fair to moderate agreements were observed between left and right lungs for the diagnosis of IAD and/or EIPH based on kappa coefficients. When sampling one lung only, the risk of incorrectly classifying a horse as a ‘control’ increased with the use of the restraint cut-off values for IAD. As BAL from one lung is not representative of the other lung in the same horse, both lungs should be sampled for a better assessment of lung cellularity and for a precise diagnosis of lower airway diseases.     

Increased adenosine concentration in bronchoalveolar lavage fluid of horses with lower airway inflammation

Several reports have suggested a role for adenosine in the pathogenesis of chronic airway conditions and this has led to new therapeutic strategies to limit airway inflammation. In this study, detectable levels of adenosine in bronchoalveolar lavage (BAL) samples from 11 horses with non-infectious lower-airway inflammation and 14 healthy controls are reported, with significantly higher values in horses with airway inflammation. Although these increased levels did not correlate with changes in neutrophil percentage in BAL, a positive association between adenosine levels and signs of lower airway inflammation (clinical score) was observed. These novel findings support the hypothesis that adenosine may contribute to bronchoconstriction and also act as a pro-inflammatory mediator in the bronchoalveolar milieu of horses with airway inflammation. Further investigation of this axis could lead to new approaches for the treatment of highly prevalent lower airway inflammatory conditions in the horse.     

Equine bronchoalveolar lavage cytology: survey of Thoroughbred racehorses in training

SUMMARY Sixty-two Thoroughbred horses aged between 1 and 7 years in training in Sydney had bronchoalveolar lavage (BAL) samples collected for cytological examination. All horses, except the yearlings and those with a cough, had raced at the time of the examination and the trainers reported satisfactory performance. Free erythrocytes were found In 73% of samples and haemoslderophages In 90% of the samples, Indicating Immediate or past occurrences of exercise-Induced pulmonary haemorrhage (EIPH). Bronchoalveolar fluid from the yearlings contained significantly less (P / 0.05) erythrocytes and haemosiderophages than samples from horses In other age groups. In the older horses, there was also more haemosiderln within the macrophages. No differences In BAL cytology could be attributed to gender, and there was no relationship between BAL cytology and racing performance. The main cytological findings were (mean ± sd): total nucleated cells - 832 ± 578/μL with the main cell types being: macrophages - 59 ± 10% (haemosiderophages - 20 ± 24%); neutrophlls - 9 ± 6%; lymphocytes - 31 ± 9%. The erythrocyte count was 10.3 ± 17.7% of the total cell count. Horses with chronic coughing had a higher proportion of macrophages and a lower proportion of lymphocytes in the leucocytes obtained from BAL. There was a higher occurrence of EIPH detected In BAL findings than that previously reported when endoscopic examination has been used to diagnose EIPH. The occurrence and severity of EIPH as Indicated by the BAL findings was found to be related to exercise Intensity. The cytological findings were similar to those reported in horses in the northern hemisphere. We conclude that BAL cytology may be useful In the diagnosis of various lower respiratory tract disorders and that exercise-induced pulmonary haemorrhage occurs In virtually all horses In race training.     

Cytological analysis of bronchoalveolar lavage fluid acquired by bronchoscopy in healthy ferrets: A pilot study

The objective of this study was to investigate the normal cytological evaluation of bronchoalveolar lavage (BAL) fluid in healthy adult ferrets (N = 12). These ferrets underwent bronchoscopy and BAL using sterile saline [1.5 mL/kg body weight (BW)]. Percentage of fluid recovered, total leukocyte count, differential leukocyte count, and cell count of the epithelial lining fluid (ELF) were determined. The mean percentage of lavage volume recovered from the right lung and left lung were 67.8 ± 14.9% and 69.7 ± 20.0%, respectively. Gender (P = 0.12) and weight (P = 0.17) did not significantly affect the mean percentage of recovered volume. The mean percentage of recovered volume (P = 0.47) and the mean leukocyte count (P = 0.17) from the right and left lung were not significantly different. Macrophages were the main leukocyte component of the lavages, followed by neutrophils, lymphocytes, and eosinophils. The mean proportion of ELF in BAL fluid was 9.3 ± 3.7% v/v. Bronchoscopy is clinically useful for collecting good quality BAL samples for cytological analysis in ferrets. The leucocyte differential was established, which may help veterinarians to make better clinical decisions when treating respiratory disease. Further studies are required with a larger group in order to establish the healthy reference intervals for BAL values in ferrets.     

The Role of Bronchoscopy in Foreign Body Removal in Dogs and Cats: 37 Cases (2000–2008)

Background: Foreign body aspiration is a differential diagnosis for acute or chronic cough that requires medical or surgical management in animals. Hypothesis: Success of bronchoscopy in airway foreign body removal is dependent on the size of the animal, duration of clinical signs, and location of the foreign body. Animals: Thirty‐two dogs and 5 cats with airway foreign bodies identified at the UC Davis Veterinary Medical Teaching Hospital. Methods: Retrospective case study evaluating the role of duration of clinical signs and body size in successful bronchoscopic removal of foreign bodies. In addition, radiographic localization of disease was compared with bronchoscopic identification. Bronchoalveolar lavage (BAL) culture and cytologic findings are reported. Results: Bronchoscopy was successful for removal of airway foreign bodies in 76% of animals (24/28 dogs and 2/5 cats), and in dogs was independent of duration of clinical signs or body size. One‐third of thoracic radiographs lacked distinctive features of an airway foreign body, and therefore radiography was unable to predict the affected site. BAL fluid at the site of the foreign body contained more neutrophils and more often had intracellular bacteria than lavage fluid from a separate site. Conclusions and Clinical Importance: Bronchoscopy was successful in removing airway foreign bodies regardless of animal size or long duration of clinical signs. Results of this study confirm the utility of bronchoscopy with lavage in management of suspected foreign bodies, even in the absence of localizing radiographic findings.     

Bronchoaveolar lavage for the diagnosis of lower airway disorders in horses

Equine pulmonary disease and especially the terminology of lower airway disease have been subject to discussion. Besides established terms such as 'Chronic Obstructive Pulmonary Disease' (COPD) and Chronic bronchitis, the term 'small airway disease' (SAD) has been introduced, for respiratory disease with inflammation in the lower airways in combination with exercise intolerance. Bronchoalveolar lavage (BAL) enables the practitioner to diagnose SAD in an early stage when there are no other signs such as coughing or exudate in the trachea. The BAL fluid is microscopically examined after centrifugation. BAL cytology, especially neutrophilia, eosinophilia, and an increase in mast cells, is important, not only to decide whether SAD is present but also to determine in the choice of therapy.     

Differential cell counts in canine cytocentrifuged bronchoalveolar lavage fluid: a study on reliable enumeration of each cell type

Background: Bronchoalveolar lavage (BAL) allows cell recovery from the lower respiratory tract; differential cell counts of BAL fluid gives important information in the assessment of various bronchial and pulmonary diseases. To the best of our knowledge no study has investigated the relation between the number of cells counted and the reproducibility of BAL fluid differential cell counts. Objective: The purpose of this study was to investigate using statistical methods how many cells should be counted in cytocentrifuged BAL fluid preparations in order to obtain a reliable enumeration of each cell type. Methods: BAL fluid samples from dogs with suspected bronchopulmonary disease were obtained during fiberoptic bronchoscopy with a standardized protocol. Differential cell counts were performed on May–Grünwald–Giemsa‐stained cytocentrifuged preparations by 2 independent observers. Reproducibility for the enumeration of each cell type was expressed as the intraclass correlation coefficient. We considered a threshold level of ≥0.90 to be high and a threshold level of ≥0.85 to be adequate. Results: Forty BAL fluid samples were included in the study. For neutrophils, alveolar macrophages, and eosinophils high reproducibility was reached by counting 200 cells; adequate reproducibility was reached for lymphocytes and bronchial epithelial cells by counting 500 cells. Conclusions: A 500‐cell differential count is required for all types of cells to be quantified with adequate reproducibility in canine cytocentrifuged BAL fluid samples.