Topic:Bronchoalveolar Lavage
Bronchoalveolar lavage (BAL) is a diagnostic procedure used to collect samples from the lower respiratory tract of horses. The technique involves the introduction of a sterile fluid into the bronchi and alveoli, which is then retrieved for analysis. BAL is utilized to assess the cellular and microbiological composition of the lower airways, aiding in the diagnosis of respiratory conditions such as inflammatory airway disease, recurrent airway obstruction, and infections. The procedure provides valuable insights into the type and extent of inflammation or infection present in the respiratory system. This page compiles peer-reviewed research studies and scholarly articles that explore the methodology, applications, and clinical relevance of bronchoalveolar lavage in equine respiratory health.
NO inhalation reduces pulmonary arterial pressure but not hemorrhage in maximally exercising horses. In horses, the exercise-induced elevation of pulmonary arterial pressure (Ppa) is thought to play a deterministic role in exercise-induced pulmonary hemorrhage (EIPH), and thus treatment designed to lower Ppa might reasonably be expected to reduce EIPH. Five Thoroughbred horses were run on a treadmill to volitional fatigue (incremental step test) under nitric oxide (NO; inhaled 80 ppm) and control (N(2), same flow rate as per NO run) conditions (2 wk between trials; order randomized) to test the hypothesis that NO inhalation would reduce maximal Ppa but that this reduction may not necessarily ...
[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 centrifu...
Plasma and bronchoalveolar fluid concentrations of nitric oxide and localization of nitric oxide synthesis in the lungs of horses with summer pasture-associated obstructive pulmonary disease. To determine concentrations of nitric oxide (NO) in plasma and bronchoalveolar lavage fluid (BALF) and localize nitric oxide synthesis in the lungs of horses with summer pasture-associated obstructive pulmonary disease (SPAOPD). Methods: 7 adult horses with SPAOPD and 6 clinically normal adult horses. Methods: Severity of SPAOPD was determined by use of clinical scores, change in intrapleural pressure (APpl) during tidal breathing, cytologic analysis of BALF, and histologic evaluation of lung specimens obtained during necropsy. Nitric oxide concentrations in plasma, BALF and epithelial lining ...
Efficacy of nasal strip and furosemide in mitigating EIPH in Thoroughbred horses. The purpose of this investigation was to study the effects of an equine nasal strip (NS), furosemide (Fur), and a combination of both (NS + Fur) on exercise-induced pulmonary hemorrhage (EIPH) at speeds corresponding to near-maximal effort. Five Thoroughbreds (526 +/- 25 kg) were run on a flat treadmill from 7 to 14 m/s in 1 m x s(-1) x min(-)1 increments every 2 wk (treatment order randomized) under control (Con), Fur (1 mg/kg iv 4 h prior), NS, or NS + Fur conditions. During each run, pulmonary arterial (Ppa) and esophageal (Pes) pressures were measured. Severity of EIPH was quantified via b...
Persistent mucin glycoprotein alterations in equine recurrent airway obstruction. Horses with the episodic asthmalike condition of recurrent airway obstruction (RAO) have bouts of inflammation and bronchoconstriction associated with indoor housing. To assess the potential differences in airway secretions between RAO-affected and control horses, methods to quantify mucus secretions were developed and applied to bronchoalveolar lavage fluid. The relative difference in the amount of mucin glycoproteins between control and RAO-affected horses was assessed with a carbohydrate side chain-specific monoclonal antibody (4E4) in an enzyme-linked immunosorbent assay and by carbohydrat...
p65 Homodimer activity in distal airway cells determines lung dysfunction in equine heaves. Nuclear factor-kappaB (NF-kappaB) activity, which is a key regulator of inflammatory gene expression, is increased in bronchial epithelial cells from horses suffering from heaves (a hypersensitivity-associated inflammatory condition of the lung). To determine whether this increased activity extends to distal airways and to other pulmonary cells, cells recovered by broncho-alveolar lavage (BAL) in healthy and heaves-affected horses were assessed for NF-kappaB activity. NF-kappaB activity was much higher in BAL cells from heaves-affected horses, especially during crisis (disease exacerbation), t...
Results of intradermal tests in horses without atopy and horses with atopic dermatitis or recurrent urticaria. To compare results of intradermal tests (IDT) for environmental allergens at 30 minutes and 4, 6, and 24 hours after injection in horses without atopy and horses with atopic dermatitis (AD) or recurrent urticaria (RU). Methods: 22 horses without atopy, 10 horses with RU, and 7 horses with AD. Methods: In all horses, medical history was obtained, and results of physical examination, hematologic examination, serum biochemical analyses, examination of bronchoalveolar lavage fluid, and IDT with 73 allergens were examined. Results: Horses with AD or RU had a significantly greater mean number of pos...
Comparison of inulin with urea as dilutional markers of bronchoalveolar lavage in healthy and heaves-affected horses. Solute analysis in bronchoalveolar lavage fluid involves the use of dilutional markers to correct for variable recovery of pulmonary epithelial lining fluid (PELF). Urea is the best characterised endogenous marker, whereas inulin appears to meet the requirements of an exogenous marker. In horses, the use of inulin has never been investigated and the impact of lower airway diseases such as heaves, on PELF recovery is unknown. In this study, five healthy and five heaves-affected horses underwent airway endoscopy and bronchoalveolar lavage. PELF recovery from bronchoalveolar lavage was calculated...
Immunity to Rhodococcus equi: antigen-specific recall responses in the lungs of adult horses. Rhodococcal pneumonia is an important disease of young horses that is not seen in immunocompetent adults. Since all foals are normally exposed to Rhodococcus equi in their environment, we hypothesized that most develop protective immune responses. Furthermore, these antigen-specific responses were hypothesized to operate throughout adult life to prevent rhodococcal pneumonia. A better understanding of the mechanisms of immune clearance in adult horses would help define the requirements for an effective vaccine in foals. Adult horses were challenged with virulent R. equi by intrabronchial inocu...
Effects of training on resting peripheral blood and BAL-derived leucocyte function in horses. In this study, the effects of prolonged, high intensity training on aspects of peripheral blood and bronchoalveolar lavage (BAL)-derived leucocyte function were evaluated in 8 horses. All horses undertook a 7 week endurance training programme, followed by 5 weeks of high intensity training (HIT). Thereafter, horses were divided into control (C) and overtraining (OT) groups. The frequency and intensity of training were increased more substantially for horses in the OT group. Training was terminated in week 32 when horses in the OT group demonstrated a significant performance reduction. Peripher...
Stabling is associated with airway inflammation in young Arabian horses. We examined the effect of stabling on upper and lower airway inflammation in 14 yearling Arabian horses that had been at pasture since birth. Horses were divided into 2 groups of 7. One group was stabled for 3 months and the other remained at pasture. The groups were then switched over for another 3 months. The nasopharynx, guttural pouches and trachea were examined endoscopically and bronchoalveolar lavage performed every month. An upper airway inflammation score was devised based on the magnitude of pharyngeal lymphoid hyperplasia and guttural pouch inflammation. During stabling this score r...
Clinical signs, evaluation of bronchoalveolar lavage fluid, and assessment of pulmonary function in horses with inflammatory respiratory disease. 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. Methods: 9 healthy horses, 5 horses with inflammatory airway disease (IAD), and 9 horses with chronic obstructive pulmonary disease (COPD). Methods: 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 horse...
Results of intradermal tests in horses without atopy and horses with chronic obstructive pulmonary disease. To compare results of intradermal tests (IDT), conducted using environmental allergens, in horses without atopy and horses with chronic obstructive pulmonary disease (COPD). Methods: 38 horses (22 horses without atopy and 16 horses with COPD). Methods: All horses were examined (physical examination, hematologic examination, serum biochemical analyses, examination of bronchoalveolar lavage fluid). An IDT was conducted, using a full panel of 73 allergens consisting of grasses, weeds, trees, molds, and insects. Results of the IDT were evaluated 30 minutes and 4, 6, and 24 hours after injection of...
MMP-9 as a marker of inflammation in tracheal epithelial lining fluid (TELF) and in bronchoalveolar fluid (BALF) of COPD horses. Gelatinolytic activity was analysed to study whether elevated activity previously found at the tracheal level of the respiratory tract of horses with chronic obstructive pulmonary disease (COPD) could also be found at the lower part of the respiratory tract. Furthermore, presence and significance of the gelatinolytic matrix metalloproteinases (MMPs) MMP-2 and MMP-9 in respiratory secretions of healthy and COPD horses were determined. Elevated gelatinolytic matrix metalloproteinases were detected in bronchoalveolar and tracheobronchial secretions from COPD horses. The main pathologically elevat...
Interleukin-8 concentration and neutrophil chemotactic activity in bronchoalveolar lavage fluid of horses with chronic obstructive pulmonary disease following exposure to hay. To analyze effects of hay dust exposure on interleukin-8 (IL-8) concentration, percentage of neutrophils, and neutrophil chemotactic activity in bronchoalveolar lavage fluid (BALF) of horses with chronic obstructive pulmonary disease (COPD). Methods: 16 healthy horses and 29 horses with COPD. Methods: IL-8 concentration, percentage of neutrophils, and neutrophil chemotactic activity in BALF were measured. Values were analyzed with respect to hay dust exposure. These variables were also measured in 5 asymptomatic horses with COPD after the induction of clinical signs by changing feed from silag...
Concentrations of gentamicin in serum and bronchial lavage fluid after intravenous and aerosol administration of gentamicin to horses. To compare concentrations of gentamicin in serum and bronchial lavage fluid after IV and aerosol administration of gentamicin to horses. Methods: 9 healthy adult horses. Methods: Gentamicin was administered by aerosolization (20 ml of gentamicin solution [50 mg/ml]) and IV injection (6.6 mg of gentamicin/kg of body weight) to each horse, with a minimum of 2 weeks between treatments. Samples of pulmonary epithelial lining fluid were collected by small volume (30 ml) bronchial lavage 0.5, 4, 8, and 24 hours after gentamicin administration. Serum samples were obtained at the same times. All sampl...
Environment and prednisone interactions in the treatment of recurrent airway obstruction (heaves). Recurrent airway obstruction (RAO) or heaves is a manifestation of a hypersensitivity to dust, moulds, and spores in the environment of a susceptible horse. Although in the majority of RAO-affected horses, clinical remission can be achieved by keeping horses at pasture to reduce their allergen exposure, this often is not practicable. For this reason, we investigated if changing the environment of a single stall in a 4 stall stable was sufficient to improve lung function and reduce inflammation in RAO-affected horses. In addition, we determined if addition of oral prednisone provided additional...
Relationship of pulmonary arterial pressure to pulmonary haemorrhage in exercising horses. Exercise-induced pulmonary haemorrhage (EIPH) is characterised by blood in the airways after strenuous exercise and results from stress failure of the pulmonary capillaries. The purpose of this experiment was to establish a threshold value of transmural pulmonary arterial pressure at which haemorrhage occurs in the exercising horse. Five geldings, age 4-14 years, were run in random order once every 2 weeks at 1 of 4 speeds (9, 11, 13, 15 m/s); one day with no run was used as a control. Heart rate, pulmonary arterial pressure and oesophageal pressure were recorded for the duration of the run. T...
Tracheobronchial mucus viscoelasticity during environmental challenge in horses with recurrent airway obstruction. The goal of this study was to compare the rheological properties of mucus from horses with recurrent airway obstruction (RAO) to that from healthy controls during environmental challenge by stabling in stalls with straw as bedding and hay as feed. We determined viscoelasticity (log G* dyn/cm2, at 10 radian/s) and calculated mucociliary clearability index (MCI) and cough clearability index (CCI), which are derivative parameters of G* and the ratio of viscosity and elasticity measured at 1 and 100 radian/s, respectively. We also investigated the solids content of mucus, and cytology of bronchoal...
Pleuropulmonary and cardiovascular consequences of thoracoscopy performed in healthy standing horses. Six healthy, awake, and pharmacologically restrained mature horses were studied in order to define the changes in cardiopulmonary function during and after exploratory thoracoscopy and to determine the presence of postoperative complications occurring 48 hours after thoracoscopy. In a randomised 3 x 3 latin square design with 2 replications, 18 procedures were performed: 6 right (RTH) and 6 left thoracoscopies (LTH) and 6 sham procedures (STH). Prior to each procedure a physical examination and a bronchoalveolar lavage fluid analysis were performed. During thoracoscopy and sham protocols, hors...
Correlation of clinical score, intrapleural pressure, cytologic findings of bronchoalveolar fluid, and histopathologic lesions of pulmonary tissue in horses with summer pasture-associated obstructive pulmonary disease. To correlate clinical score, intrapleural pressure, cytologic findings of bronchoalveolar lavage fluid (BALF), and histologic lesions of pulmonary tissue in horses affected with summer pasture-associated obstructive pulmonary disease (SPAOPD). Methods: 8 adult horses affected with SPAOPD and 6 adult horses without evidence of respiratory tract disease. Methods: Clinical score, change in intrapleural pressure (deltaPpl) during tidal breathing, results of cytologic examination and bacteriologic culture of BALF, and results of histologic examination of pulmonary parenchyma were evaluated. Results...
Effect of exercise and COPD crisis on isoprostane concentration in plasma and bronchoalveolar lavage fluid in horses. To test whether isoprostanes could be used as markers of oxidative stress in horses, their concentration was determined in plasma and in pulmonary epithelial lining fluid (PELF) in 3 models of oxidative stress: (1) strenuous exercise, (2) acute COPD crisis and (3) exercise combined with COPD crisis. Four horses were investigated twice, once in crisis and once in remission. The animals underwent a standardised treadmill exercise test. Isoprostane assessment was performed in plasma and bronchoalveolar lavage fluid 24 h before and 1 h after exercise and in plasma also immediately after exercise. ...
A preliminary study of the effect of inhaled nitric oxide on lung mechanics in the standing horse with histamine-induced bronchoconstriction. The effect of inhaled nitric oxide on pulmonary mechanics was studied in normal standing horses with histamine-induced bronchoconstriction. The respiratory health status of 6 normal horses was established on the basis of history, clinical and bronchoalveolar lavage examination. Intrathoracic pressures were estimated using distal oesophageal pressures. Respiratory gas flows were measured using a heated pneumotachograph. Pulmonary mechanics variables were determined from these measurements on a breath by breath basis. Bronchoconstriction was induced by nebulizing a 0.75% w/v solution of histamin...
Functional and compositional changes in pulmonary surfactant in response to exercise. Pulmonary surfactant from bronchoalveolar lavages was obtained from 2 groups of horses. A control group consisting of 6 healthy racehorses that were paddock-rested and lavaged weekly for 6 consecutive weeks were compared with an experimental group of 10 healthy racehorses, lavaged weekly the same period, consisting of a 5 week incremental-intensity treadmill training programme and one week post training paddock rest. Phospholipid content of lavage fluid was determined indirectly by phosphorus assay, and surfactant functional activity was determined by bubble surfactometry. Total cell counts an...
Sequential changes in bronchoalveolar cytology after autologous blood inoculation. Six horses, free of recent exercise-induced pulmonary haemorrhage (EIPH), each had 8 bronchial segments inoculated with 40 ml of autologous blood lavaged on Days 3, 5, 7, 10, 14 and 21 after inoculation. The bronchoalveolar lavage (BAL) fluid samples were analysed, and total leucocyte counts and differential cell percentages determined. Statistical analysis of the differences between the 8 post inoculation and 1 pre-inoculation (control) lavage sites demonstrated an early neutrophilic response, rising from < 5% of alveolar leucocytes to 10% by 24-48 h post inoculation. As this response wane...
Effect of exercise on concentrations of immunoreactive endothelin in bronchoalveolar lavage fluid of normal horses and horses with chronic obstructive pulmonary disease. Chronic obstructive pulmonary disease (COPD) represents a major cause of loss of performance in the horse. The role of endothelin (ET), a potent bronchoconstrictive and vasoactive peptide, is currently being investigated in asthma and other obstructive respiratory diseases in man. We have previously found elevated systemic and pulmonary endothelin levels in horses during exacerbation of COPD. In the present study, our aim was to examine possible variations in ET concentrations occurring during exercise in COPD horses. We compared the effects of intense treadmill exercise on the recovery of end...
Blood gas, plasma lactate and bronchoalveolar lavage cytology analyses in racehorses with respiratory disease. The purpose of this study was to evaluate the relationship between bronchoalveolar lavage (BAL) cytology, arterial blood gases and plasma lactate concentration during a standardised treadmill test (STT) in racehorses with small-airway inflammation (SAI), or exercise-induced pulmonary haemorrhage (EIPH). Sixteen Thoroughbred and 20 Standardbred actively racing racehorses, were divided into a control group (n = 10), EIPH group (n = 13) and SAI group (n = 13). Each STT consisted of a 2 min trot at 4 m/s followed by 5 x 1 min, incremental speed steps (6, 8, 10, 11 and 12 m/s) at 10% incline for Th...
In vitro allergen-induced degranulation of pulmonary mast cells from horses with recurrent airway obstruction (heaves). To determine the capacity of pulmonary mast cells (PMC) to degranulate in response to various potential allergens and other secretagogues in horses with recurrent airway obstruction (heaves) and clinically normal horses before and after exposure to moldy hay. Methods: 5 horses with heaves and 5 clinically normal horses. Methods: Heaves was characterized as an increased clinical respiratory score and maximum change in transpulmonary pressure of > 20 cm H2O after exposure. Bronchoalveolar lavage was performed during each period. Washed and resuspended cells were exposed for 20 minutes at 37 C wi...
Phenotypic analysis of bronchoalveolar lavage fluid lymphocytes in horses with chronic pulmonary disease. A panel of specific antibodies against CD3, CD4, CD5, CD8, MHC I and II was used in single and two colour flow cytometry to define T cell subpopulations in bronchoalveolar lavage fluid of horses affected with chronic obstructive pulmonary disease and of healthy controls. According to the results of the clinical examination including bronchoscopy and cytology of the tracheal aspirate the horses were divided into four groups (healthy, subclinically to mildly affected; moderately affected, and severely affected). All groups of horses had a similar percentage of CD3+ cells in the BALF. Compared to...
Transferability of cephalothin to the alveolar cavity in thoroughbreds. Five Thoroughbreds were classified into 4 groups according to the administration method used for saline solution (saline), ambroxol, and cephalothin sodium (cephalothin). In group A, cephalothin was injected intravenously after oral administration of ambroxol. In group B, cephalothin was injected intravenously after oral administration of saline. Groups C and D were used as control groups. The dose of cephalothin or ambroxol was clinically administrated. Venous blood and bronchoalveolar lavage fluid (BALF) were sampled from each group. In groups A and B, cephalothin concentrations in plasma re...