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.
Physiological measurements and upper and lower respiratory tract evaluation in French Standardbred Trotters during a standardised exercise test on the treadmill. There are a variety of reasons for poor performance in racehorses. Exercise intolerance has often been associated with subclinical respiratory abnormalities, and diagnostic aids are therefore used to enhance clinical detection. Physiological variables can also be measured in order to evaluate the metabolic reponse to exercise. This study evaluated the relationship between physiological measurements and upper airway videoendoscopy during a standardised treadmill exercise test and bronchoalveolar lavage (BAL) cytology in control horses (good racing performance, n = 14) and poor performers (n = 2...
Antioxidant supplementation and pulmonary function at rest and exercise. Antioxidants have been implicated in the reduction and prevention of oxidative stress during exercise. We hypothesised that a dietary supplement containing a mixture of natural antioxidants together with vitamins E, C and selenium, given for 4 weeks, would increase the systemic and pulmonary antioxidant capacity leading to a reduction in markers of oxidative damage and an improvement in pulmonary function during exercise. In 6 healthy horses studied, the antioxidant supplement significantly increased plasma concentrations of ascorbic acid (from mean +/- s.d. 16 +/- 7 to 23 +/- 4 micromol/l; P ...
Airway cooling and mucosal injury during cold weather exercise. In human subjects that exercise strenuously in cold weather, there is evidence that hyperventilation with cold air leads to peripheral airway cooling, desiccation and mucosal injury. Our hypothesis was that hyperventilation with cold air can result in penetration of unconditioned air (air that is not completely warmed and humidified) into the peripheral airways of exercising horses, resulting in peripheral airway mucosal injury. To test this hypothesis, a thermister-tipped catheter was inserted through the midcervical trachea and advanced into a sublobar bronchus in three horses that cantered ...
Evaluation of nebulised hay dust suspensions (HDS) for the diagnosis and investigation of heaves. 2: Effects of inhaled HDS on control and heaves horses. To evaluate inhaled hay dust suspensions (HDS) as a tool for the diagnosis and investigation of heaves, the pulmonary inflammatory and functional consequences of inhalation challenge with 3 different HDS were determined in 6 control and 7 asymptomatic heaves horses. Heaves horses given HDS challenge developed the characteristic features of heaves, including airway neutrophilia, obstructive airway dysfunction and mucus hypersecretion. While HDS challenge induced a mild airway neutrophilia in controls, the no-response threshold for controls was greater than that of heaves horses, and there was n...
Interleukin-4 and interferon-gamma gene expression in summer pasture-associated obstructive pulmonary disease affected horses. We hypothesised that horses affected with summer pasture-associated obstructive pulmonary disease (SPAOPD) react to an allergen or allergens in their summer environment that is either absent or present at lower levels in their winter environment; and that such allergens stimulate SPAOPD-affected horses to produce a different T helper lymphocyte cytokine profile from that of control horses. The primary objective of this study was to determine the cytokine mRNA profile of T helper lymphocytes obtained from summer pasture-associated obstructive pulmonary disease (SPAOPD) affected horses when 1) t...
Cytological analysis of equine bronchoalveolar lavage fluid. Part 2: Comparison of smear and cytocentrifuged preparations. The aim of this study was to develop a diagnostically useful smear method for preparation of equine bronchoalveolar lavage fluid (BALF) for use by practitioners. A smear method for equine BALF preparation which included the addition of serum was developed, and cell morphology, differential cell counts (DCC) and repeatability of counting DCC compared with those of cytocentrifuged BALF preparations. BALF samples (n = 21) were collected from 5 control horses and 5 heaves-susceptible horses. Smear preparations of BALF produced smaller, darker, staining cells, making cytological identification more...
Cytological analysis of equine bronchoalveolar lavage fluid. Part 3: The effect of time, temperature and fixatives. Bronchoalveolar lavage fluid (BALF) samples are often subject to time delays, possibly with temperature fluctuations, between collection and processing. The aim of this study was to evaluate the effects of time, temperature and 2 different fixatives on equine BALF cytology, in order to develop guidelines for optimal equine BALF storage conditions. Total nucleated cell count (TCC), differential cell counts (DCC), absolute cell counts (ACC), cell viability, cell morphology and bacterial growth of BALF samples stored at 4, 18 (+/- addition of formalin- or alcohol-based fixatives) and 38 degrees C...
Cytological analysis of equine bronchoalveolar lavage fluid. Part 1: Comparison of sequential and pooled aliquots. The aim of this study was to investigate whether initial equine bronchoalveolar lavage fluid (BALF) aliquots were more representative of bronchial cytology that bronchiolar and alveolar cytology. Cell viability and total nucleated (TCC), differential (DCC) and absolute cell counts of cytocentrifuged preparations of 3 sequentially collected BALF aliquots (Aliquots 1-3) were compared with those of pooled BALF (Aliquot 4) to assess whether all aliquots were representative of the lavaged lung segment. BALF samples (n = 21) were collected from control horses (n = 5) or heaves-affected horses (n = 5...
A novel model for equine recurrent airway obstruction. Equine recurrent airway obstruction (RAO; a term combining both chronic obstructive pulmonary disease (COPD) and summer pasture associated obstructive pulmonary disease (SPAOPD)) is one of the most common equine respiratory diseases with up to 50% of horses affected worldwide. The etiopathogenesis of RAO is unknown although pulmonary hypersensitivity to inhaled mold antigens may be involved. Recent work in our laboratory demonstrating elevated levels of IL-4 and IL-13 mRNA in the airways and peripheral blood of horses with RAO is consistent with an atopic component to RAO. Little is known rega...
Alveolar macrophage graded hemosiderin score from bronchoalveolar lavage in horses with exercise-induced pulmonary hemorrhage and controls. The objective of this study was to determine if a quantitative scoring system for evaluation of hemosiderin content of alveolar macrophages obtained by bronchoalevolar lavage provides a more sensitive test for the detection of exercise-induced pulmonary hemorrhage (EIPH) in horses than does endoscopy of the lower airways. A sample population composed of 74 Standardbred racehorses aged 2-5 years was used. Horses were grouped as either control (EIPH-negative) or EIPH-positive based on history and repeated postexertional endoscopic evaluation of the bronchial airways. Bronchoalveolar lavage was p...
Cytokine induction in pulmonary airways of horses with heaves and effect of therapy with inhaled fluticasone propionate. Work in humans and laboratory animals has identified a central role for cytokines and chemokines in development and persistence of lower airway inflammation. The objectives of this study were to determine interleukin (IL)-1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha induction in bronchoalveolar lavage (BAL) of control horses and horses with heaves both during remission and exacerbation of the disease, and to determine the effect of therapy with inhaled fluticasone propionate on the cytokine profile of horses with heaves. IL-1 beta an...
Comparison of effects of dexamethasone and the leukotriene D4 receptor antagonist L-708,738 on lung function and airway cytologic findings in horses with recurrent airway obstruction. To evaluate whether the leukotriene (LT) D4 receptor antagonist L-708,738 is therapeutically beneficial in treating horses with recurrent airway obstruction (heaves). Methods: 12 adult horses with heaves and healthy lung lobes from 20 slaughtered horses. Methods: Lung lobes were used for smooth muscle tension and radioligand binding studies. Horses with heaves were given a placebo for 14 days and administered L-708,738 (n = 6; 2.5 mg/kg PO, q 12 h) or dexamethasone (6; 0.04 mg/kg, IV, q 24 h) from days 14 to 28. Pulmonary function was measured weekly for 36 days, and bronchoalveolar cells were...
Effects of pentoxifylline on pulmonary function and results of cytologic examination of bronchoalveolar lavage fluid in horses with recurrent airway obstruction. To determine the effects of pentoxifylline (PTX) administration on lung function and results of cytologic examination of bronchoalveolar lavage fluid in horses affected by recurrent airway obstruction (RAO). Methods: 10 RAO-affected horses. Methods: 6 horses were orally administered PTX (16 g) mixed with corn syrup, and 4 horses were administered corn syrup alone, twice daily for 14 days. Pulmonary function was evaluated before administration (day 0) and on days 8 and 15. Bronchoalveolar lavage (BAL) was performed on days 0 and 15. Reversibility of airway obstruction was assessed by measuring ...
Clinical, radiographic, endoscopic, bronchoalveolar lavage and lung biopsy findings in horses with exercise-induced pulmonary hemorrhage. A clinical study was performed to determine whether clinical, endoscopic, radiographic, bronchoalveolar lavage (BAL) cytological, and pulmonary biopsy findings could be correlated in horses with exercise-induced pulmonary hemorrhage (EIPH) compared with controls. Racing standardbred horses were selected as either EIPH (n = 10) or control (n = 10), based on repeated postexertional endoscopy of the lower airways. Complete physical and respiratory examinations were performed and blood samples were submitted for arterial blood gas analysis, hematologic study, and fibrinogen determination. Bilatera...
Inhalation of organic dusts and lipopolysaccharide increases gelatinolytic matrix metalloproteinases (MMPs) in the lungs of heaves horses. We report the effects of mouldy hay/straw exposure, inhaled hay dust suspension (HDS) and inhaled lipopolysaccharide (LPS) on bronchoalveolar lavage fluid (BALF) gelatinolytic matrix metalloproteinase (MMP) levels and degree of activation in healthy (n = 6) and heaves- (previously termed chronic obstructive pulmonary disease) affected (n = 6 or 7) horses. Gelatinolytic MMPs in BALF were quantified by zymography, and gelatinases were shown by Western immunoblotting to be MMP-2 and MMP-9. Hay/straw and HDS challenges increased BALF total gelatinolytic activity only in heaves horses, with the maj...
Antigen challenge increases adherence of circulating neutrophils in horses with chronic obstructive pulmonary disease. Activation of circulating neutrophils has been observed following challenge of horses with chronic obstructive pulmonary disease (COPD) and may facilitate the accumulation of these cells in the airways. In this study, no significant difference was observed between adherence to protein coated plastic of blood neutrophils from asymptomatic COPD-susceptible and normal horses stimulated by the mediators PAF, human recombinant (hr)IL-8 and hrC5a. Twenty-four hours after the start of a 7 h antigen challenge, adherence of unstimulated neutrophils from COPD-susceptible horses increased from 2.5 (0.5-4...
Efficacy of three corticosteroids for the treatment of heaves. This study used a cross-over design to compare the efficacy of 3 corticosteroids for the relief of airway obstruction and inflammation in 9 heaves-affected horses. The severity of airway obstruction and inflammation was quantified by measurement of lung function and by bronchoalveolar lavage fluid (BALF) cytology, respectively. Airway obstruction was induced by stabling the horses and they remained stabled during the 10 day treatment period. Lung function was measured before treatment (baseline), at Days 3, 7, and 10 of treatment, and after 30 days at pasture. BALF cytology was investigated at...
Bronchoalveolar lavage for the diagnosis and treatment of pneumonia associated with transport in Thoroughbred racehorses. To evaluate a hypothese that use of bronchoalveolar lavage (BAL) for early treatment of pneumonia would improve their prognosis by reducing bacterial numbers and excessive numbers of neutrophils in the lung, initial experiences with BAL in the diagnosis and treatment of pneumonia were performed in 36 racehorses that became ill within 24 hr of long distance travel (1,200-1,600 km, 26-32 hr) by road. Comparisons were made of the outcomes of the 36 horses and those of 42 horses (81.0% recovered, 50.0% returned to racing) treated for transport associated pneumonia without BAL. The total amount of ...
IgG antibody responses to an inhaled antigen in horses with “heaves” (recurrent airway obstruction). A controlled experimental system for the evaluation of pulmonary immune responses in horses with "heaves" (recurrent airway obstruction) has been developed. We hypothesized that the humoral immune response to an inhaled antigen in diseased horses would be different from that of healthy horses and that chronic pulmonary inflammation would bias the production of IgG isotypes in diseased horses as compared to healthy horses. Healthy and affected horses were housed in a natural challenge environment (stabled, fed dusty hay) and exposed by inhalation, to a nebulized solution of keyhole limpet hemoc...
Pharmacokinetics of azithromycin and concentration in body fluids and bronchoalveolar cells in foals. To determine the pharmacokinetics of azithromycin and its concentration in body fluids and bronchoalveolar lavage cells in foals. Methods: 6 healthy 6- to 10-week-old foals. Methods: Azithromycin (10 mg/kg of body weight) was administered to each foal via i.v. and intragastric (i.g.) routes in a crossover design. After the first i.g. dose, 4 additional i.g. doses were administered at 24-hour intervals. A microbiologic assay was used to measure azithromycin concentrations in serum, peritoneal fluid, synovial fluid, pulmonary epithelial lining fluid (PELF), and bronchoalveolar (BAL) cells. Resul...
Effects of an external nasal strip and frusemide on pulmonary haemorrhage in Thoroughbreds following high-intensity exercise. The purpose of this study was to examine the effects of an external nasal strip (NS), frusemide (FR) and a combination of the 2 treatments (NS + FR) on exercise-induced pulmonary haemorrhage (EIPH) in Thoroughbred horses. It was hypothesised that both the NS and FR would attenuate EIPH as assessed by red blood cell count in bronchoalveolar lavage fluid. In random order, 8 horses completed each of 4 sprint exercise tests on a treadmill: 1) NS; 2) FR (0.5 mg/kg bwt i.v., 4 h pre-exercise); 3) NS + FR; and 4) control (C; no treatment). After a 5 min warm-up (4.5 m/s), horses completed 2 min runni...
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...