Airway Inflammation: What the Research Says

Evidence from 47 peer-reviewed studies

1 Systematic Review

7 RCT

27 Cohort Study

5 Case Report

7 Expert Opinion

What Professionals Should Know

•Environmental management (reducing airborne dust) is critical for achieving clinical remission and preventing irreversible airway damage in asthmatic horses
•Current medication comparisons are limited by lack of direct clinical trials; use evidence-based selection while advocating for better comparative research
•Early intervention may be important to prevent progression from reversible to irreversible airway changes
•Inhaled ciclesonide can effectively reduce clinical signs and airway inflammation in racehorses with moderate asthma, offering a practical treatment option beyond current severe asthma indications
•Measurable improvements in cough and inflammatory markers occur within 10 days of treatment, making this a viable option for managing racing performance issues related to moderate asthma
•This therapy targets mastocytic inflammation specifically; efficacy in other asthma phenotypes (neutrophilic/eosinophilic) is unproven and may require different therapeutic approaches
•Soaked hay effectively controls airway obstruction in horses with severe asthma, with benefits evident within 2-6 weeks
•Alfalfa pellets provide a simpler feeding alternative but with less dramatic improvement in lung function
•The practical inconvenience of the soaking protocol (45-minute immersion, waste disposal) may limit client compliance despite proven efficacy
•Administer N-acetylcysteine at 15 mg/kg/day orally for 3 days before transportation to significantly reduce airway inflammation and mucus accumulation during 18+ hour head confinement events
•NAC treatment restores normal inflammatory cell profiles in airways, reducing neutrophilic airway disease risk—a practical intervention for sport horse transporters
•Consider NAC supplementation as a preventive strategy to reduce post-transportation respiratory complications and maintain performance careers in transported horses
•Intramuscular serum and RGT treatment offer glucocorticoid-free alternatives for managing mild equine asthma, eliminating medication withdrawal concerns for racehorses
•Both treatments effectively reduced airway inflammation markers (neutrophils and mast cells) with effects persisting 10 weeks after completing therapy
•Tracheal wash cytology did not reflect treatment response; bronchoalveolar lavage appears necessary for accurate assessment of treatment efficacy in mild asthma
•p38 MAPK inhibitors may have potential for preventing RAO in susceptible horses during high-risk periods, but current formulations are not suitable for treating active disease episodes
•Toxicity concerns with MRL-EQ1 (behavioral and hematologic side effects) limit clinical utility; safer p38 inhibitors would be needed before recommending this class for equine respiratory disease
•Corticosteroids remain superior to p38 inhibitors for treating acute RAO exacerbations based on this evidence
•IV dexamethasone is the most reliable rapid treatment for acute heaves episodes, producing lung function improvement within 3 days during stabling
•IM dexamethasone-21-isonicotinate offers convenient dosing every 3 days but expect treatment failure in approximately 10-15% of cases
•Oral prednisone is unreliable for acute relief and requires at least 10 days to show effect in some horses—not recommended for acute crisis management
•Environmental management (reducing dust and mould exposure through bedding and feed changes) should be the primary treatment strategy for RAO, as significant clinical improvement occurs within 3 days without medication
•While prednisone reduces inflammation markers more rapidly, it does not speed up functional improvement in airway obstruction—focus resources on stable management rather than solely on corticosteroid therapy
•Even modifying a single stall's environment in a multi-stall barn can benefit RAO-affected horses, making this approach practical for facilities where full pasture turnout is not feasible
•Do not rely solely on positive tracheal wash culture results to justify antimicrobial therapy in asthmatic horses, as these results do not confirm bacterial infection or predict disease severity
•A positive tracheal wash culture in an asthmatic horse may represent contamination or colonisation rather than pathogenic infection, so clinical judgment should integrate other diagnostic findings
•Consider withholding or reconsidering antimicrobial treatment in asthmatic horses with positive tracheal wash cultures unless other evidence of bacterial infection is present
•Outdoor horses experience measurable airway cytological changes across seasons even without clinical signs; practitioners should monitor at-risk horses more closely during spring and winter months
•Endobronchial biopsies did not add diagnostic value in this cohort and may not be necessary for routine respiratory assessment in asymptomatic horses
•Seasonal variation in airway immune markers suggests climatic factors influence equine respiratory status—consider this when evaluating recurrent respiratory issues in outdoor-kept horses
•Bilateral BAL sampling should be considered over pooled or single-lung samples when assessing horses for airway disease, as one lung may not represent the overall condition
•Left and right lungs show different cellular profiles (particularly mast cells), requiring standardized sampling protocols for consistent diagnosis
•Longitudinal monitoring is important as horses can transition between control and inflammatory states; single assessments may miss subclinical changes
•Horses stabled in arid Western regions face substantially higher inorganic dust exposure—farriers and veterinarians should prioritize aggressive dust control measures (wet bedding, ventilation, air filtration) in these areas
•The different inflammatory response (lower neutrophils but higher particulate load in Western horses) suggests geogenic dust may trigger different airway pathology than traditional organic dust, affecting treatment strategies
•Consider geographic location as a risk factor when evaluating recurrent airway obstruction; horses in arid climates may need enhanced management protocols regardless of stable conditions
•When investigating a horse with severe asthma, routinely assess for concurrent upper airway disorders using overground endoscopy, as nearly 70% of SEA cases involve palatal dysfunction
•Some palatal disorders (particularly palatal instability) may resolve with effective asthma treatment alone, without requiring separate surgical intervention—prioritize treating the underlying inflammatory disease
•Monitor airway inflammation markers in horses with both SEA and palatal disorders, as concurrent disease appears to worsen lower airway pathology
•The type of lavage solution (acidic vs. neutral pH) does not affect the post-BAL neutrophil response in healthy horses, so continue using standard saline for cost and practicality
•Expect neutrophil counts to increase substantially 48 hours after BAL regardless of solution used; interpret cytology results with awareness of this expected inflammatory response timing
•This finding supports current BAL protocols and eliminates the need to switch to more expensive neutral pH solutions in hopes of reducing post-procedure airway inflammation
•This research establishes a reproducible method for studying extracellular vesicles in equine respiratory disease, which may eventually help identify biomarkers for asthma diagnosis or progression.
•The similarity in EV concentrations between asthmatic and healthy horses suggests future studies need to characterize EV protein composition and function rather than just particle number to understand their role in airway inflammation.
•For practitioners, this foundational work may lead to improved diagnostic tools for equine asthma in coming years, though clinical applications are not yet available.
•Feeding haylage instead of dry hay can reduce respirable dust and endotoxin exposure by 60-70%, with measurable benefits for airway health in training horses
•Horses transitioned to haylage show reduced airway neutrophilia within 2-6 weeks, suggesting improved respiratory status during intense training
•For racehorses with recurrent airway obstruction or dust sensitivity, haylage should be considered as a practical management tool to mitigate environmental irritants and inflammation
•When reviewing equine airway cytology results, always verify whether the laboratory included or excluded epithelial cells, as this significantly affects interpretation—particularly for tracheal wash samples where 21% of cases can be reclassified
•Request explicit documentation of methodology from your diagnostic laboratory and maintain consistency within your practice to ensure accurate trending and treatment decisions
•Consider advocating for industry consensus on epithelial cell reporting standards to improve diagnostic reliability across veterinary practices
•Lung cytology via non-endoscopic BAL offers a practical tool to assess deep airway inflammation in calves without requiring endoscopy, potentially improving respiratory disease diagnosis on farm
•Correlating cytology findings with clinical signs and ultrasound consolidation may help target antimicrobial treatment more precisely and reduce unnecessary antibiotic use in respiratory disease
•Consider implementing lung sampling protocols in group-housed calves with respiratory signs to better understand subclinical inflammation patterns before disease progresses
•Nebulisation of injectable DSP could offer a cost-effective alternative to other corticosteroid delivery methods for horses with asthma, provided systemic absorption is low
•Before adopting this technique clinically, confirm that preservatives in the formulation do not trigger airway inflammation or adverse respiratory responses
•If safety and bioavailability are confirmed, this approach could allow targeted lung delivery while minimising systemic side effects
•BALF neutrophil percentage provides a quantifiable marker of airway disease severity in asthmatic horses, helping clinicians assess exacerbation severity
•Elevated neutrophilia on BALF cytology indicates ongoing structural damage to airways and lung tissue, warranting aggressive treatment and management intervention
•Serial BALF neutrophil monitoring may help guide treatment decisions and assess response to therapy in horses with recurrent airway obstruction
•Tracheal wash is a more reliable diagnostic method than bronchoalveolar lavage for detecting airway inflammation in your patient population, with superior sensitivity and specificity
•Current clinical cutoff values (>20% neutrophils for TW, >5% for BAL) remain appropriate for diagnosing airway inflammation despite slightly different optimal ROC thresholds
•The two sampling methods show good agreement overall, so choice may depend on clinical feasibility, but TW appears preferable if airway inflammation diagnosis is your primary goal
•Optimize stall ventilation and design to minimize dust accumulation—this is a modifiable factor that directly impacts airway health and racing performance
•Implement dust control management practices throughout the day, particularly focusing on bedding, hay quality, and ventilation to reduce both large and small particulates
•Regular endoscopic monitoring of tracheal mucus can serve as a practical indicator of stall air quality; excessive mucus suggests need for immediate environmental improvements
•Breathing pattern variability loss detected by RIP monitoring may identify early RAO disease onset before standard lung function tests show obstruction—useful for monitoring stabled horses at risk
•Non-invasive telemetric RIP monitoring can be applied continuously (24 h/d) to detect subtle changes in respiratory dynamics that precede clinical signs of airway obstruction
•Stabling triggers detectable changes in RAO-affected horses within 8 hours; consider this timeline when assessing respiratory response to housing changes in susceptible horses
•New racehorses entering training should be monitored closely for visible tracheal mucus as a key indicator of airway inflammation; this is more clinically useful than neutrophil counts in tracheal wash samples
•Airway inflammation improves with time in training environment rather than chronological age—ensure adequate acclimatization period for horses new to racing
•Current diagnostic criteria for inflammatory airway disease may overweight neutrophil counts; practitioners should focus on visible mucus and clinical signs when making management decisions
•Low-dust environmental management alone is insufficient to resolve airway obstruction in RAO horses; persistent peripheral airway damage likely reflects irreversible structural remodeling requiring ongoing medical intervention
•Standard lung function tests may underestimate RAO severity—forced expiratory maneuvers are more sensitive for detecting persistent peripheral airway obstruction in apparently stable horses
•Absence of elevated airway neutrophils on BAL fluid analysis does not indicate resolution of RAO pathology; clinical monitoring and advanced lung function testing remain necessary despite normal cytology
•RAO in horses involves platelet activation as part of the inflammatory cascade, suggesting potential therapeutic targets beyond traditional anti-inflammatory approaches
•Understanding platelet involvement in RAO may inform development of new treatment strategies for airway disease in affected horses
•Veterinarians should consider systemic inflammatory mechanisms when managing horses with recurrent airway obstruction
•Horses with RAO show significant antioxidant depletion in the trachea when exposed to organic dust, suggesting bedding choice and stable management are critical in managing this condition
•The trachea appears to bear a greater oxidant load than peripheral airways during dust exposure, indicating that reducing dust exposure at the source is particularly important for RAO-affected horses
•Monitoring ascorbic acid status or considering antioxidant supplementation may be relevant therapeutic approaches for managing RAO, though further research is needed
•A single lung biopsy sample can reliably represent the entire lung for diagnosis of diffusely distributed airway diseases in horses
•Reducing airway inflammation through targeted therapy is a rational approach to managing excessive mucus production in heaves-affected horses
•Mucus overproduction involves structural changes (metaplasia) rather than just increased secretion, suggesting long-term management strategies should focus on preventing airway inflammation
•Clenbuterol may offer dual benefits in RAO management—both bronchodilation and reduced airway inflammation—making it a valuable therapeutic option for horses with this condition
•The drug's ability to modulate macrophage cytokine production suggests potential value in reducing recurrent flare-ups triggered by environmental allergen challenges
•Consider IV clenbuterol administration for RAO-susceptible horses, particularly those exposed to hay dust or fungal antigens that typically trigger inflammatory responses
•During endoscopic examination of underperforming racehorses, prioritise assessment of tracheal mucus accumulation as a potential performance-limiting factor—visible mucus grades 2-4 warrant investigation and intervention.
•Do not rely solely on tracheal neutrophil counts or cell turbidity to diagnose clinically significant airway disease; direct visualisation of mucus is more predictive of performance issues.
•Consider tracheal mucus a legitimate differential diagnosis for poor racing performance and implement airway management strategies targeting mucus clearance and prevention.
•Heaves-susceptible horses show exaggerated matrix metalloproteinase responses to environmental challenges, which may explain their enhanced susceptibility to airway disease and could guide identification and management of at-risk individuals
•Protease inhibitor therapy may represent a novel treatment approach to reduce airway inflammation in heaves by targeting the underlying MMP-mediated tissue damage pathway
•Environmental dust exposure should be minimized in heaves-susceptible horses, as dose-dependent inflammatory responses indicate that cumulative dust exposure significantly worsens airway pathology
•RAO-affected horses have compromised antioxidant defenses and may suffer greater respiratory damage from air quality problems; consider air quality management and stable environment optimization
•Environmental ozone exposure presents a specific oxidative challenge for RAO horses; monitor air quality during high ozone days and adjust exercise/turnout accordingly
•Enhanced nutritional antioxidant support may be particularly beneficial for RAO-affected horses to compensate for reduced pulmonary antioxidant capacity
•Conventional stable housing environments expose all sport horses to subclinical airway inflammation; consider environmental management strategies (ventilation, bedding type, dust control) even for clinically healthy performers
•Age alone does not predict increased subclinical airway disease in sport horses, but the clinical significance of subclinical IAD on athletic performance remains unclear and warrants investigation
•Visual endoscopic assessment of mucus does not reliably predict inflammatory cytology findings; clinical evaluation should consider both endoscopic and cytological data when assessing subclinical airway disease
•Oxidative stress is a measurable component of heaves pathology; monitoring antioxidant status via blood glutathione in resting horses and uric acid in exercising horses may help assess disease severity
•Heaves-affected horses show exaggerated oxidative stress responses to exercise, suggesting careful management of work intensity during crisis phases
•Local airway inflammation in heaves produces distinct oxidative stress signatures in lung fluid that differ from systemic markers, indicating both local and systemic involvement of the disease process
•Stabling young Arabian horses increases both upper and lower airway inflammation; consider pasture management as a management strategy to reduce airway disease risk
•If stabling is necessary, monitor stabled horses more frequently for signs of airway disease and consider supplementary anti-inflammatory support
•Extended pasture time appears to have a protective effect on airway health in young horses, suggesting turnout should be maximized when possible
•Dexamethasone treatment in horses may trigger sustained neutrophil activation in airways lasting 1-2 weeks, with potential implications for horses with concurrent respiratory infections
•Tracheal wash neutrophil counts and elastase/myeloperoxidase levels can serve as markers for monitoring airway neutrophil activation and degranulation in clinical cases
•Systemic biomarkers (serum surfactant protein D) may not reliably reflect lower airway inflammation, necessitating direct sampling via bronchoalveolar lavage for accurate assessment
•Understanding Hif1α's role in RAO may lead to novel therapeutic targets for managing heaves, potentially beyond current dust avoidance and anti-inflammatory strategies
•This finding connects cellular hypoxia and immune dysregulation in RAO, suggesting that improving airway oxygenation and reducing inflammatory hypoxia may be mechanistically important
•Future treatments targeting Hif1α pathways could represent a new approach to controlling the persistent airway inflammation characteristic of RAO
•RAO involves impaired innate immune signaling rather than typical allergic responses, suggesting current treatment approaches may need reconsideration
•Understanding that TLR2 pathway dysfunction in RAO could inform development of targeted anti-inflammatory therapies beyond standard corticosteroid use
•Environmental management remains critical since housing conditions trigger RAO despite underlying immune defects in affected horses
•Hay dust quality matters significantly—moulds and endotoxin levels in hay are key drivers of airway inflammation in heaves-prone horses; prioritize clean, dust-free forage management
•MMP inhibition may offer future therapeutic options for treating and preventing heaves, providing a rationale for pursuing anti-inflammatory strategies beyond dust avoidance
•Dust exposure recommendations should focus on mould contamination thresholds rather than total dust burden alone, since mould content is the primary driver of pathological MMP response
•Bacterial infection is an important cause of lower respiratory disease in racehorses; tracheal wash culture with quantification (>10³ CFU/ml) can guide diagnosis and treatment decisions
•Routine viral serology has limited diagnostic value for acute coughing in racehorses and should not be relied upon as sole basis for diagnosis
•More than half of coughing cases have no identifiable infectious agent at presentation, suggesting need for investigation of environmental, inflammatory, and other non-infectious factors
•When you see a horse with chronic cough and exercise intolerance, perform systematic diagnostic workup to determine the asthma phenotype—this classification will directly inform your treatment plan
•Medication alone won't solve equine asthma; you must identify and eliminate environmental triggers (dust, mold, ammonia, poor ventilation) or the horse will remain symptomatic despite therapy
•Use short-acting bronchodilators for immediate relief during hyperpneic episodes, but build your management around long-term anti-inflammatory drugs and environmental control to prevent progressive airway damage
•Severe equine asthma is a chronic condition in adult horses triggered by environmental aeroallergen exposure in genetically susceptible individuals; management should focus on minimizing allergen exposure and controlling airway inflammation
•Understanding that both Th-cell mediated and neutrophilic inflammatory pathways drive the disease may guide future targeted treatment strategies beyond current standard therapies
•Genetic testing for ECA13 and ECA15 regions may become useful for identifying at-risk horses, though current research gaps suggest more studies are needed before clinical implementation
•Tamoxifen may be therapeutically beneficial for horses with severe asthma through mechanisms other than NET suppression; in vivo studies in affected horses are needed to confirm clinical utility
•Understanding tamoxifen's effects on equine neutrophil function could inform treatment protocols for inflammatory airway disease, though this remains experimental
•Current evidence is limited to laboratory work on healthy horses; clinical application requires further investigation in naturally-occurring disease
•Glucocorticoids are essential for managing equine asthma, but clinicians need better guidance on drug selection and dosing optimization to maximize efficacy while minimizing adverse effects
•Further research is needed to establish minimal effective doses and comparative effectiveness of different glucocorticoid preparations to improve individual treatment protocols
•Monitor for glucocorticoid-specific adverse effects in asthmatic horses and consider long-term management strategies given the chronic nature of the disease
•RAO management prioritizes dust elimination through environmental control—this is more effective than medication alone and can resolve clinical signs within 3-4 weeks
•Horses with RAO need lifelong allergen management as they remain chronically susceptible; prevention of exposure is key to maintaining health
•When clinical signs persist despite environmental changes, corticosteroids and bronchodilators can improve pulmonary function, but should support rather than replace dust control measures
•Stable management strategies should address both fine and coarse particle control, as different particle sizes have distinct inflammatory effects on airways
•Consider seasonal variations in particle distribution when implementing dust control measures and timing training schedules
•Monitor and manage regional differences in air quality within racing facilities, as particle exposure varies by location within stables
•Heaves-susceptible horses are significantly more sensitive to inhaled endotoxin than healthy horses; stable management to reduce dust and endotoxin exposure is critical for these animals
•Poor stable environments with high airborne endotoxin can trigger airway inflammation in normal horses, making ventilation and bedding management important preventive measures for all horses
•Heaves is multifactorial; controlling endotoxin exposure alone may not resolve clinical signs but is an important component of comprehensive management alongside addressing other environmental triggers

Key Research Findings

Equine asthma is characterized by reversible airflow obstruction, bronchial hyper-responsiveness, and airway inflammation triggered by airborne agent exposure in susceptible horses

Calzetta L, 2017

Clinical remission is achievable in low-airborne dust environments, but repeated exacerbations can lead to irreversible airway remodelling

Calzetta L, 2017

Available pharmacotherapy evidence comes from multiple small studies with no head-to-head clinical trials comparing available medications

Calzetta L, 2017

Inhaled ciclesonide treatment for 10 days significantly reduced HOARSI scores (P=0.002) and cough during exercise (P=0.001) in treated racehorses compared to placebo

Sanz Macarena G, 2025

Treatment decreased mast cell percentage in bronchoalveolar lavage fluid (P=0.02; -2.96%) on Day 10 compared to placebo

Sanz Macarena G, 2025

Treated horses showed reduced gene expression of inflammatory cytokines IL-6 (P=0.002) and IL-13 (P=0.03) in BAL cells over the 10-day period

Sanz Macarena G, 2025

Ciclesonide efficacy was demonstrated in moderate asthma without environmental modification, though effects on neutrophilic or eosinophilic asthma phenotypes remain unclear

Sanz Macarena G, 2025

Soaked hay reduced lung resistance by 1.31 cmH₂O/L/s over 6 weeks (P<0.001) in horses with severe asthma

Westerfeld Roxane, 2024

Alfalfa pellets reduced lung resistance by 1.06 cmH₂O/L/s over 6 weeks (P=0.03, not significant after correction)

Westerfeld Roxane, 2024

Soaked hay showed greater improvement in airway obstruction compared to alfalfa pellets

Westerfeld Roxane, 2024

Protocol required hay to be soaked for 45 minutes and dried-out hay discarded between meals

Westerfeld Roxane, 2024

NAC treatment significantly reduced endoscopic mucus scores compared to confined head without treatment (CH vs NAC, p<0.05)

Tavanaeimanesh Hamid, 2024

BAL cell counts were significantly lower in NAC group (34,291±2,624 cells/μL in CH vs reduced in NAC)

Tavanaeimanesh Hamid, 2024

Neutrophil percentage decreased from 53.8±8% in CH to 20.08±8% in NAC-treated horses

Tavanaeimanesh Hamid, 2024

Macrophage percentage increased from 35.7±10% in CH to 66.33±9% in NAC-treated horses, indicating reduced inflammatory response

Tavanaeimanesh Hamid, 2024

Evidence Base

Pharmacological treatments in asthma-affected horses: A pair-wise and network meta-analysis.

Calzetta L, Roncada P, di Cave D et al. (2017) — Equine veterinary journal

Systematic Review

Use of inhaled ciclesonide for treatment of moderate asthma in Thoroughbred racehorses.

Sanz Macarena G, Jellen Georgia, Cody Lauren et al. (2025) — Journal of veterinary internal medicine

RCT

Effects of soaked hay on lung function and airway inflammation in horses with severe asthma.

Westerfeld Roxane, Payette Flavie, Dubuc Valérie et al. (2024) — Journal of veterinary internal medicine

RCT

The efficacy of N-acetylcysteine in decreasing airway inflammation and mucus accumulation in horses with 18 hours of head confinement.

Tavanaeimanesh Hamid, Alinia Zahra, Sadeghian Chaleshtori Sirous et al. (2024) — Journal of veterinary internal medicine

RCT

Evaluation of Treatment With Respiratory Gene Technology and Serum in a Group of Standard Bred Racehorses With Cytological Evidence of Mild Equine Asthma.

Hansen Sanni, Laustsen Louise, Otten Nina D et al. (2021) — Journal of equine veterinary science

RCT

Effects of a MAPK p38 inhibitor on lung function and airway inflammation in equine recurrent airway obstruction.

Lavoie J P, Thompson D, Hamilton E et al. (2008) — Equine veterinary journal

RCT

Efficacy of three corticosteroids for the treatment of heaves.

Robinson N E, Jackson C, Jefcoat A et al. (2002) — Equine veterinary journal

RCT

Environment and prednisone interactions in the treatment of recurrent airway obstruction (heaves).

Jackson C A, Berney C, Jefcoat A M et al. (2000) — Equine veterinary journal

RCT

Tracheal wash culture is not associated with bronchial infection, remodelling or inflammation in horses with asthma.

Leduc Laurence, St-Jean Guillaume, Lavoie Jean-Pierre (2026) — Equine veterinary journal

Airway Inflammation: What the Research Says

What Professionals Should Know

Key Research Findings

Evidence Base

Pharmacological treatments in asthma-affected horses: A pair-wise and network meta-analysis.

Use of inhaled ciclesonide for treatment of moderate asthma in Thoroughbred racehorses.

Effects of soaked hay on lung function and airway inflammation in horses with severe asthma.

The efficacy of N-acetylcysteine in decreasing airway inflammation and mucus accumulation in horses with 18&#x2009;hours of head confinement.

Evaluation of Treatment With Respiratory Gene Technology and Serum in a Group of Standard Bred Racehorses With Cytological Evidence of Mild Equine Asthma.

Effects of a MAPK p38 inhibitor on lung function and airway inflammation in equine recurrent airway obstruction.

Efficacy of three corticosteroids for the treatment of heaves.

Environment and prednisone interactions in the treatment of recurrent airway obstruction (heaves).

Tracheal wash culture is not associated with bronchial infection, remodelling or inflammation in horses with asthma.

Influence of climatic changes on respiratory health in a teaching herd of outdoor-housed horses.

Bilateral bronchoalveolar lavage cytology profiles in a warmblood horse population during a 1-year period.

A cross-sectional observational study of birefringent particulates in bronchoalveolar lavage cytology in horses with equine asthma from the West v East coasts of the USA.

Co-Occurrence of Severe Equine Asthma and Palatal Disorders in Privately Owned Pleasure Horses.

Effect of Lavage Solution Type on Bronchoalveolar Lavage Fluid Cytology in Clinically Healthy Horses.

Isolation of Extracellular Vesicles From the Bronchoalveolar Lavage Fluid of Healthy and Asthmatic Horses.

Dust exposure and pulmonary inflammation in Standardbred racehorses fed dry hay or haylage: A pilot study.

Effect of inclusion or exclusion of epithelial cells in equine respiratory cytology analysis.

Factors associated with lung cytology as obtained by non-endoscopic broncho-alveolar lavage in group-housed calves.

Bioavailability and tolerability of nebulised dexamethasone sodium phosphate in adult horses.

Bronchoalveolar lavage fluid neutrophilia is associated with the severity of pulmonary lesions during equine asthma exacerbations.

Comparison of Tracheal Wash and Bronchoalveolar Lavage Cytology in 154 Horses With and Without Respiratory Signs in a Referral Hospital Over 2009-2015.

Local airborne particulate concentration is associated with visible tracheal mucus in Thoroughbred racehorses.

Telemetric analysis of breathing pattern variability in recurrent airway obstruction (heaves)-affeeted horses

Descriptive results from a longitudinal study of airway inflammation in British National Hunt racehorses.

Lung function and airway cytologic profiles in horses with recurrent airway obstruction maintained in low-dust environments.

Platelet activation in ponies with airway inflammation.

Comparison of the antioxidant status in tracheal and bronchoalveolar epithelial lining fluids in recurrent airway obstruction.

Airway inflammation is associated with mucous cell metaplasia and increased intraepithelial stored mucosubstances in horses.

The anti-inflammatory effects of IV administered clenbuterol in horses with recurrent airway obstruction.

Effect of tracheal mucus and tracheal cytology on racing performance in Thoroughbred racehorses.

Dose responses to inhalation of endotoxin, hay dust suspension and Aspergillus fumigatus extract in horses as measured by levels and activation of matrix metalloproteinase-9.

Antioxidant and inflammatory responses of healthy horses and horses affected by recurrent airway obstruction to inhaled ozone.

Airway inflammation and mucus in two age groups of asymptomatic well-performing sport horses.

Effect of chronic airway inflammation and exercise on pulmonary and systemic antioxidant status of healthy and heaves-affected horses.

Stabling is associated with airway inflammation in young Arabian horses.

Stimulation of airway neutrophils following dexamethasone administration and equid herpesvirus-2 challenge in horses.

Increased hypoxia-inducible factor 1&#x3b1; expression in lung cells of horses with recurrent airway obstruction.

Expression of toll-like receptor 2 mRNA in bronchial epithelial cells is not induced in RAO-affected horses.

Effect of composition and different fractions of hay dust suspension on inflammation in lungs of heaves-affected horses: MMP-9 and MMP-2 as indicators of tissue destruction.

A case-control study of respiratory disease in Thoroughbred racehorses in Sydney, Australia.

Chronic Cough and Hyperpnea: Clinical Approach to Equine Asthma.

The Immune Mechanisms of Severe Equine Asthma-Current Understanding and What Is Missing.

Glucocorticoid treatment in horses with asthma: A narrative review.

Equine Recurrent Airway Obstruction

Particle mapping in stables at an American Thoroughbred racetrack.

Pulmonary and systemic effects of inhaled endotoxin in control and heaves horses.

The efficacy of N-acetylcysteine in decreasing airway inflammation and mucus accumulation in horses with 18 hours of head confinement.

Increased hypoxia-inducible factor 1α expression in lung cells of horses with recurrent airway obstruction.