Equine Asthma: What the Research Says

Evidence from 59 peer-reviewed studies

5 Systematic Review

6 RCT

21 Cohort Study

5 Case Report

20 Expert Opinion

2 Thesis

What Professionals Should Know

•Prioritize forage quality and processing methods (soaking/steaming hay) as first-line environmental management, but plan for nutritional supplementation when hygienic treatment reduces nutrient content
•Implement non-straw bedding and enhance barn ventilation systems as core stable management practices for asthmatic horses
•Focus client education on demonstrating genuine clinical benefits of environmental modifications—owner buy-in is the limiting factor in achieving control of equine asthma
•When assessing poor performance in racehorses without structural airway abnormalities, be aware that current evidence linking specific diagnostic tests to performance outcomes is inconsistent and anecdotal — do not rely on single tests for definitive diagnosis
•Standardized performance metrics are urgently needed across the racing industry to properly evaluate the true impact of conditions like equine asthma and EIPH on individual horses
•Request or advocate for higher-quality, controlled performance studies in your racing practice and facility to better inform evidence-based intervention decisions rather than relying on current variable evidence
•Current evidence for bronchodilator efficacy in equine asthma is limited and underpowered, requiring more robust clinical research
•Lung function improvements from bronchodilators may not directly correlate with clinical improvement in individual asthmatic horses
•Veterinarians should base treatment decisions on clinical observation rather than assuming bronchodilator-induced lung function improvements automatically translate to clinical benefit
•Inhaled corticosteroids are effective for managing equine asthma and preventing exacerbations; consider as first-line therapy
•Systemic corticosteroids should be reserved for selected cases with symptomatic airway hyperresponsiveness during acute exacerbations, not routine use
•Use the IDEASS scoring system to quantify asthma severity and objectively monitor treatment response in affected horses
•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
•Lidocaine nebulization appears microbiologically safe as an alternative to glucocorticosteroids for asthma treatment, without disrupting the healthy respiratory bacterial community
•Clinical assessment and respiratory sampling site selection matter—nasal and tracheal samples yield different microbial profiles and should not be used interchangeably
•Lower respiratory tract sampling in healthy horses may require specialized protocols due to low bacterial density
•Ciclesonide is a suitable alternative to dexamethasone for managing equine asthma without the risk of systemic immunosuppression
•If using dexamethasone for asthma control, be aware it will suppress systemic immune markers (granzyme B, interferon-γ); consider duration and frequency of treatment
•Inhaled corticosteroid therapy with ciclesonide allows local airway treatment while minimizing systemic immune effects, improving clinical safety
•For horses with equine asthma or recurrent airway inflammation, consider switching from wood shavings to peat bedding to reduce lower airway neutrophilic response
•Bedding material selection has measurable effects on airway inflammation markers even in healthy horses; this effect will likely be more pronounced in asthmatic individuals
•Respiratory rate and visible mucus scores may not be sensitive indicators of bedding-related airway inflammation—cytological examination provides more definitive assessment
•For horses with equine asthma, steamed hay is the preferred treatment method over soaking due to superior dust reduction and microbial control that persists through storage
•If soaking is used, feed treated hay immediately—storing soaked hay even at cool temperatures rapidly increases mold, yeast, and bacterial contamination within 6-24 hours
•Expect steamed hay to be eaten more slowly with increased chewing activity, which may improve digestion efficiency and prolong feeding time for enrichment
•For horses with equine asthma or respiratory sensitivity, baled peat bedding is superior to straw pellets and loosely stored peat in reducing airway inflammation
•Wood pellet bedding performs similarly to baled peat and may be a practical alternative if peat availability or cost is a concern
•Storage and packaging matter: keep peat bales plastic-covered rather than loose to minimize dust and inflammatory triggers in the stable environment
•Ciclesonide is an effective inhaled corticosteroid for treating equine asthma with similar lung function improvements to systemic dexamethasone but without cortisol suppression and associated systemic side effects
•The improved safety profile of ciclesonide makes it suitable for longer-term management of asthma in horses where repeated systemic corticosteroid use is contraindicated
•Experimentally induced asthma may respond differently to treatment than naturally occurring exacerbations, so clinical efficacy in field conditions requires further validation
•Use hay quality assessment tools (like the hay-shaker device) to make informed hay selection decisions that support respiratory health in stabled horses, particularly for asthmatic individuals
•Monitor feeding behaviour and hay contact patterns in individual horses, as these significantly influence dust exposure independent of hay quality itself
•Consider environmental factors (temperature, humidity, stabling conditions) alongside hay quality when managing dust exposure, as these modify the relationship between hay dustiness and breathing zone exposure
•Soaking hay is a highly effective, practical mitigation strategy that reduces dust exposure by >50%, making it a valuable tool for managing equine asthma and respiratory health
•Wearable PM monitors can now be calibrated and used on individual horses to quantify exposure and track effectiveness of dust-reduction interventions
•Even brief 20-minute measurements after feeding capture meaningful differences in PM exposure between feeding practices, allowing practical farm-level monitoring
•If investigating respiratory disease in horses, obtain BALF and submit for fungal culture rather than relying on tracheal wash or cytology alone, as culture from BALF is most clinically meaningful
•Fungal airway colonization appears more relevant to mild-moderate asthma than severe asthma, so environmental fungal exposure management may be particularly important for managing intermediate cases
•High tracheal mucus scores or elevated BALF neutrophils combined with fungal culture positivity support a diagnosis of moderate asthma and warrant investigation of dusty/moldy hay and bedding
•Myostatin testing cannot currently be recommended as a diagnostic tool for equine asthma in clinical practice
•Clinical examination and bronchoalveolar lavage fluid cytology remain the standard methods for confirming equine asthma diagnosis
•Further research is needed before any blood-based biomarker can be validated for early detection of equine respiratory disease
•HA levels in lung fluid may serve as a measurable biomarker to assess severity of equine asthma and monitor disease progression in affected horses
•Understanding HA's role in airway inflammation and remodelling could inform therapeutic strategies targeting extracellular matrix changes in chronic equine respiratory disease
•Horses with moderate to severe neutrophilic airway inflammation show structural airway changes that accumulate with disease severity, suggesting progressive nature of untreated equine asthma
•Vitamin D supplementation is unlikely to be an effective therapeutic strategy for managing equine asthma based on this evidence of unchanged serum levels across disease severity
•Equine asthma pathophysiology differs from human asthma regarding vitamin D involvement, suggesting different nutritional intervention approaches are needed
•Focus respiratory management efforts on other proven environmental and treatment modalities rather than vitamin D repletion
•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
•Tracheal mucus accumulation on endoscopy is a reliable indicator of asthma risk and should be actively assessed during respiratory evaluation
•Presence of fungi in tracheal wash alone should not be used as a diagnostic marker for equine asthma without other clinical findings
•Environmental matching is important for asthma assessment—shared barn exposure does not explain asthma cases, suggesting individual susceptibility factors are key
•Bronchoalveolar lavage fluid analysis using protein microarray provides superior diagnostic utility compared to blood serum testing for identifying allergen sensitization in asthmatic horses
•Blood serum allergen-specific IgE testing has limited clinical value for asthma diagnosis in horses and may lead to misdiagnosis if used as a standalone diagnostic tool
•Suspected equine asthma cases warrant BALF collection and analysis rather than relying on serological testing alone for allergen-specific diagnosis
•Horses with summer pasture-associated asthma show distinct allergic inflammation patterns; diagnosis and management should focus on allergen avoidance and anti-inflammatory strategies rather than antimicrobial approaches
•The elevation of IL-5 and other Th2 cytokines suggests that affected horses may benefit from targeted therapeutic interventions aimed at modulating allergic responses
•Clinicians should recognize that pasture-associated asthma in tropical environments represents a chronic allergic condition requiring environmental and management modifications for long-term control
•When performing BALF cytology on asthmatic horses, include GMC counts in the routine assessment—this simple addition may help distinguish disease severity and identify horses with concurrent mastocytosis
•The presence of increased GMC appears linked to mast cell recruitment in the lung; this shared mechanism may explain some respiratory signs and could guide targeted treatment strategies
•Tachypnea in asthmatic horses may correlate with GMC and mastocyte activity even without obvious respiratory effort at rest, helping clinicians recognize subtle disease progression
•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.
•Maternal lineage genetics appear important for asthma risk in breeding programmes; consider maternal inbreeding coefficients when selecting breeding stock for primitive horse breeds
•Management and environmental factors differ significantly between studs; investigate housing, ventilation, and stabling practices as potential asthma contributors alongside genetics
•Routine monitoring for coughing and nasal discharge in certain maternal and paternal lines may enable earlier identification and management of equine asthma cases
•Standard allergy testing panels (intradermal, serology, in vitro) should not be relied upon to confirm or exclude equine asthma diagnosis in clinical practice
•Allergen inhalation provocation testing may be more clinically relevant than conventional allergy tests, but delayed reactions (6+ hours) require extended monitoring periods
•Management of equine asthma should focus on environmental dust/allergen reduction strategies rather than depending on allergy test results to guide therapy
•Dietary management alone may be insufficient to restore normal microbiota function in asthmatic horses; microbiota-targeted interventions warrant investigation
•Environmental factors (pasture vs. indoor housing) and hay quality significantly alter fecal microbiota, suggesting integrated management strategies may benefit asthmatic horses
•Dysbiotic microbiota in asthmatic horses may perpetuate systemic inflammation; monitoring and modulating gut health could become adjunctive therapeutic targets for managing equine asthma
•Monitor horses with respiratory sensitivity during high air pollution days; respiratory signs may appear 2-3 weeks after pollution exposure peaks
•Use local Air Quality Health Index (AQHI) data to anticipate increased airway inflammation risk and adjust training/outdoor exposure accordingly for susceptible horses
•Consider environmental air quality as a modifiable risk factor in managing horses with inflammatory airway disease alongside traditional management strategies
•EBC pH and H2O2 levels may be useful noninvasive diagnostic tools for detecting lower airway inflammation when endoscopy or bronchoalveolar lavage is not immediately available
•Environmental conditions (temperature and humidity) during sample collection can significantly affect biomarker results, so standardization of collection procedures is important for reliable interpretation
•This technique offers a potentially less invasive alternative to traditional airway sampling methods for monitoring airway disease progression and treatment response in individual horses
•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
•RAO involves systemic immune dysregulation affecting cell trafficking and proliferation, not just local airway inflammation—management should address environmental triggers comprehensively
•Individual horses may show different immune responses depending on genetic background and specific environmental exposures (hay dust vs. other allergens)
•Understanding the molecular basis of RAO supports the rationale for environmental management (hay quality, dust reduction) as primary prevention strategy
•Adenosine signalling pathways represent a novel therapeutic target for modulating lower airway inflammation in horses with equine asthma or recurrent airway obstruction
•Selective A(2A) adenosine receptor antagonists may enhance anti-inflammatory responses in airway-compromised horses and warrant further investigation as potential treatments
•Future clinical trials should evaluate adenosine receptor ligands as adjunctive therapies for managing equine lower airway disease, particularly in cases with elevated neutrophilic inflammation
•The HIVE method offers practical advantages for field and clinical settings due to its gentle workflow and compatibility with sensitive cells, making it potentially useful for equine respiratory diagnostics
•Current HIVE implementation has technical limitations in capturing granulocytes and mast cells in mixed BAL samples; practitioners should be aware these cell populations may be underrepresented in results
•Further method optimization is needed before widespread clinical adoption for comprehensive BAL cell characterization in equine asthma cases
•Nebulized lidocaine shows promise as a potential corticosteroid-sparing option for equine asthma with good local airway penetration and no observed safety concerns in healthy horses
•Clinicians should be aware that while well-tolerated, some horses may develop increased airway reactivity to provocative stimuli post-nebulization, warranting further safety evaluation in asthmatic populations
•Current evidence is limited to healthy horses; efficacy and safety must be confirmed in clinically affected asthmatic horses before clinical adoption
•Maintaining optimal body condition (BCS <7) may help prevent equine asthma development and should be a primary management target for at-risk horses
•Overweight horses presenting with respiratory signs warrant careful evaluation for asthma, as obesity appears to be a modifiable risk factor
•Weight management programs may be a cost-effective preventive strategy for lower airway disease in equine populations
•EIT may offer a non-invasive alternative to flowmetric plethysmography for detecting airway reactivity and changes consistent with equine asthma
•Regional analysis of lung ventilation using EIT provides detailed airflow distribution data that could help localize respiratory dysfunction in clinical cases
•Further validation in larger populations of affected horses is needed before implementing EIT as a diagnostic tool in clinical practice
•RAO involves measurable abnormalities in lung surfactant composition, suggesting a biochemical basis for airway dysfunction beyond simple inflammation
•Surfactant deficiency in RAO-affected horses may explain their increased susceptibility to bronchoconstriction and difficulty clearing secretions during episodes
•This finding opens potential therapeutic avenues (surfactant supplementation) that warrant further investigation for clinical application in RAO management
•Adding enrichment to turnout areas—especially foraging opportunities—can significantly improve observed behavior and reduce problematic stereotypies, with no need to increase turnout size to be effective
•Managers report that enrichment correlates with improvement in common health conditions like laminitis, lameness, and EMS, suggesting it may be a practical welfare tool alongside other management strategies
•Forage-based enrichment appears most impactful for calmness and natural behaviors; structural elements add benefits for confidence and handling; consider combining types for maximum effect
•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
•For respiratory research using equine samples, size exclusion chromatography should be preferred over centrifugation methods when investigating extracellular vesicle composition and cellular origins
•The equine model offers practical advantages for longitudinal respiratory disease studies due to naturally occurring asthma, sample volume availability, and physiological similarities to human respiratory pathology
•This methodological optimization may improve future diagnostic or prognostic applications of extracellular vesicles in equine respiratory disease assessment
•A smartphone-based AI diagnostic tool could enable preliminary equine asthma screening at the barn or in field settings without specialized equipment
•This technology may allow horse handlers and veterinarians to identify respiratory disease earlier, potentially improving outcomes and reducing costs of invasive diagnostics
•Non-invasive screening could streamline case selection for horses requiring more advanced diagnostic workup such as endoscopy or bronchoalveolar lavage
•Antimicrobial use in equine asthma cases is inconsistent globally, suggesting opportunity to align practice with non-infectious nature of the condition and improve stewardship
•Tracheal wash culture results should guide antimicrobial use rather than presumptive treatment; consider whether clinical presentation truly indicates bacterial infection before prescribing
•Ensure your antimicrobial prescribing in asthma cases aligns with current ACVIM consensus definitions and your country's regulations to avoid unnecessary use of critical antimicrobial classes
•Cytokine profiling in BALF may help differentiate EA subtypes and guide targeted immunomodulatory therapies
•Elevated IL-1β and neutrophils correlate with increased airway resistance, suggesting innate immunity as a key driver in some EA cases
•IL-4 elevation in mixed granulocytic EA and its inverse correlation with airway reactance suggests Th2-mediated responses may have distinct functional consequences than pure neutrophilic inflammation
•Consider gut health as part of a comprehensive asthma management strategy in horses; dysbiosis may contribute to respiratory disease susceptibility
•Microbiota-modulating interventions (probiotics, prebiotics, FMT) may represent emerging treatment options alongside traditional asthma management protocols
•Monitor and optimize dietary factors that support beneficial gut microbiota composition in horses with respiratory disease
•Consider exercise stress testing and environmental factors (cold air, chlorine exposure) when BALF cytology appears normal but subclinical asthma is suspected
•Understand that tracheal aspirate cytology helps rule out bacterial infection while BALF cytology determines inflammatory subtype and disease severity
•Be aware that respiratory effort at rest is the key clinical indicator of severe equine asthma, and that multiple concurrent conditions (especially exercise-induced pulmonary hemorrhage) may complicate diagnosis
•Individual horses with asthma require personalized assessment of their specific phenotype and triggers rather than uniform treatment protocols, as disease presentation varies significantly between affected animals.
•Work with veterinarians to identify the underlying inflammatory profile and pathological features in each asthmatic horse to guide targeted therapy selection.
•Expect emerging evidence-based precision medicine approaches in equine asthma management adapted from human respiratory medicine in coming years to improve treatment outcomes.
•Environmental control should be prioritized alongside medical treatment, as modifying environmental risk factors can meaningfully improve outcomes for asthmatic horses
•Horse owners and veterinarians should work together to identify and reduce environmental triggers specific to each horse's situation
•Understanding environmental risk factors enables proactive management to prevent asthma symptom development in at-risk horses
•Veterinarians should tailor client education on condition severity and management to address knowledge gaps, particularly for metabolic and respiratory conditions where owner understanding is lowest
•Recognize that owners' emotional responses to equine illness directly correlate with their perception of disease impact; counseling should address both horse welfare and owner wellbeing
•Discussions about quality of life, pain management, and end-of-life care are critical touch points for owners making health decisions—prioritize these conversations in clinical practice
•Non-invasive nasal brush sampling could enable larger, more feasible research studies on equine asthma by replacing invasive bronchial biopsy procedures
•This alternative sampling method may accelerate translation of asthma research findings into clinical therapies by reducing practical barriers to recruitment
•Findings suggest Notch signalling pathways warrant investigation as potential therapeutic targets for managing equine airway inflammation
•Withaferin A shows promise as a potential therapeutic agent for equine conditions involving excessive neutrophilic inflammation (asthma, laminitis, ischemia-reperfusion injury), though clinical efficacy in horses has not yet been demonstrated
•This is foundational in vitro research; significant additional work needed to determine optimal dosing, bioavailability, and safety in live horses before clinical application
•Consider monitoring emerging research on WFA as a potential adjunctive anti-inflammatory therapy, but do not use clinically in horses until in vivo and clinical trials are completed
•MSC therapy is emerging as a potential treatment for multiple equine conditions beyond joint and tendon injuries, but clinical protocols are not yet standardized for routine use
•The horse serves as a valuable translational model for human diseases due to similarities in disease pathogenesis, particularly for wound healing, laminitis, and metabolic disorders
•Current evidence supports further research but practitioners should await robust clinical trials before adopting MSC therapies for non-musculoskeletal conditions in their practice
•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
•Current diagnostic options for asthma are limited in the field—expect improved, more accessible tests in the coming years as the Equine Asthma Group develops standardized guidelines.
•Asthma in horses has multiple causes (infectious, non-infectious, genetic); management strategies should be tailored based on individual phenotype rather than assuming one-size-fits-all approaches.
•Work with your veterinarian to stay updated on emerging diagnostic markers and phenotype-specific treatments as this field rapidly evolves through improved research-practice collaboration.
•MSC therapy represents a promising alternative to long-term corticosteroid treatment for chronic inflammatory conditions like equine asthma and recurrent uveitis, but clinical protocols are not yet standardized for practice
•Consider collecting and cryopreserving MSC sources (bone marrow, adipose, umbilical cord) from young or healthy horses before illness or injury occurs, as this may become standard preventative practice
•Current clinical applications of MSCs remain primarily in musculoskeletal regeneration; expansion to systemic inflammatory conditions awaits additional research on safety, dosing, and administration protocols
•This in vitro model provides a more physiologically relevant system for studying equine asthma mechanisms compared to monoculture, potentially improving understanding of epithelial-mesenchymal interactions in airway disease
•The established co-culture system may enable better preclinical testing of asthma therapeutics and investigation of how structural remodelling occurs in chronically inflamed equine airways
•RAO is a chronic obstructive airway disease in horses similar to human asthma; understanding recognition and early detection is critical for effective management
•Diagnostic approaches and treatment protocols should be implemented by practitioners to improve respiratory function and performance in affected horses
•Environmental management and veterinary intervention are key components of RAO treatment strategies
•Genetic testing for respiratory disease susceptibility in horses may become available as candidate genes like IL4RA are validated, potentially allowing early identification of at-risk individuals
•Understanding the genetic basis of RAO could enable selective breeding to reduce disease prevalence in equine populations
•Practitioners should be aware that respiratory disease phenotypes must be carefully defined to make accurate genetic associations and clinical diagnoses
•Steamed hay remains beneficial for horses with respiratory disease as it reduces allergens and microorganisms, but diets must be supplemented with additional protein and amino acids to compensate for the 35-50% reduction in digestible nutrients
•Monitor horses on steamed hay for protein status; consider adding high-quality protein sources or amino acid supplements, particularly lysine, methionine, and cysteine
•While steaming solves respiratory problems, it creates a nutritional trade-off—ensure dietary balancing is prioritized alongside allergen reduction strategies
•This recellularization protocol provides a novel research tool to investigate molecular mechanisms driving asthmatic airway remodeling in horses, potentially leading to improved therapeutic targets beyond current limited treatment options
•The demonstration that ASM cells preferentially repopulate the smooth muscle matrix layer validates the use of equine bronchial scaffolds as a physiologically relevant model for studying ECM-cell interactions in equine asthma

Key Research Findings

Forage type, production method, and contamination during manufacture/storage are primary environmental factors in equine asthma etiology

Diez de Castro Elisa, 2024

Hay soaking and steaming reduce airborne dust and improve hygienic quality but decrease nutritional value requiring supplementation

Diez de Castro Elisa, 2024

Avoiding straw bedding and improving barn ventilation are recommended environmental management strategies when pasture turnout is not feasible

Diez de Castro Elisa, 2024

Owner compliance and education are the most critical factors determining success of environmental asthma management protocols

Diez de Castro Elisa, 2024

Of 996 publications identified, only 20 met criteria for detailed analysis using the QUIPS tool, indicating limited high-quality evidence in this field

Cullinane Ann, 2023

Evidence supporting the relationship between proposed diagnostic indicators of non-structural airway disease and poor performance is variable and often conflicting

Cullinane Ann, 2023

Conflicting reports exist regarding the impact of equine asthma and EIPH on athletic performance in Thoroughbreds

Cullinane Ann, 2023

Lack of standardization in measuring racehorse performance across studies makes comparison of findings and meta-analysis impossible

Cullinane Ann, 2023

Few and underpowered clinical studies have investigated the impact of bronchodilators on clinical signs in asthma-affected horses

Calzetta L, 2020

Airway obstruction is the main trait of severe equine asthma affecting respiratory function

Calzetta L, 2020

There is uncertainty about minimal important difference between lung function improvements and clinical sign improvement in equine asthma

Calzetta L, 2020

Corticosteroids significantly improved clinical condition in equine asthma with SMD of -1.52 compared to control (P<0.001)

Calzetta L, 2018

No significant difference detected between inhaled and systemic corticosteroids in clinical score improvements (P=0.8)

Calzetta L, 2018

IDEASS scoring system showed corticosteroids improved clinical condition by 30% compared to controls (P<0.001)

Calzetta L, 2018

A one-point change in IDEASS represents the minimally clinically detectable difference in equine asthma

Calzetta L, 2018

Evidence Base

Environmental Management of Equine Asthma.

Diez de Castro Elisa, Fernandez-Molina Jose Maria (2024) — Animals : an open access journal from MDPI

Systematic Review

A Scoping Review of Non-Structural Airway Disease as a Cause of Poor Performance in Racehorses.

Cullinane Ann, Garvey Marie, Walsh Cathal et al. (2023) — Animals : an open access journal from MDPI

Systematic Review

Clinical efficacy of bronchodilators in equine asthma: Looking for minimal important difference.

Calzetta L, Crupi R, Roncada P et al. (2020) — Equine veterinary journal

Systematic Review

Clinical effect of corticosteroids in asthma-affected horses: A quantitative synthesis.

Calzetta L, Rogliani P, Page C et al. (2018) — Equine veterinary journal

Systematic Review

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

Nebulization of 2% lidocaine has no detectable impact on the healthy equine respiratory microbiota.

Holley Lauren, Creasey Hannah N, Bedenice Daniela et al. (2025) — PloS one

RCT

The Effect of Inhaled Ciclesonide Treatment on Systemic Markers of Immune Function in Horses.

Page Allen E, Johnson Mackenzie, Parker Jordan L et al. (2023) — Journal of equine veterinary science

RCT

Effects of Bedding Material on Equine Lower Airway Inflammation: A Crossover Study Comparing Peat and Wood Shavings.

Mönki Jenni, Saastamoinen Markku, Karikoski Ninja et al. (2021) — Frontiers in veterinary science

RCT

Feed Intake Parameters of Horses Fed Soaked or Steamed Hay and Hygienic Quality of Hay Stored following Treatment.

Glatter Maren, Bochnia Mandy, Wensch-Dorendorf Monika et al. (2021) — Animals : an open access journal from MDPI

RCT

Effects of Bedding Material on Equine Lower Airway Inflammation: A Comparison of Two Peat Beddings, Wood Pellet, and Straw Pellet.

Mönki Jenni, Saastamoinen Markku, Karikoski Ninja et al. (2021) — Frontiers in veterinary science

RCT

Effect of different doses of inhaled ciclesonide on lung function, clinical signs related to airflow limitation and serum cortisol levels in horses with experimentally induced mild to severe airway obstruction.

Lavoie J-P, Bullone M, Rodrigues N et al. (2019) — Equine veterinary journal

RCT

Minimising feeding behaviour interference: A hay-shaker device to assess dust exposure in horses.

Bouverat, Naef, Dolf et al. (2025) — Equine veterinary journal

Equine Asthma: What the Research Says

What Professionals Should Know

Key Research Findings

Evidence Base

Environmental Management of Equine Asthma.

A Scoping Review of Non-Structural Airway Disease as a Cause of Poor Performance in Racehorses.

Clinical efficacy of bronchodilators in equine asthma: Looking for minimal important difference.

Clinical effect of corticosteroids in asthma-affected horses: A quantitative synthesis.

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

Nebulization of 2% lidocaine has no detectable impact on the healthy equine respiratory microbiota.

The Effect of Inhaled Ciclesonide Treatment on Systemic Markers of Immune Function in Horses.

Effects of Bedding Material on Equine Lower Airway Inflammation: A Crossover Study Comparing Peat and Wood Shavings.

Feed Intake Parameters of Horses Fed Soaked or Steamed Hay and Hygienic Quality of Hay Stored following Treatment.

Effects of Bedding Material on Equine Lower Airway Inflammation: A Comparison of Two Peat Beddings, Wood Pellet, and Straw Pellet.

Effect of different doses of inhaled ciclesonide on lung function, clinical signs related to airflow limitation and serum cortisol levels in horses with experimentally induced mild to severe airway obstruction.

Minimising feeding behaviour interference: A hay-shaker device to assess dust exposure in horses.

A wearable real-time particulate monitor demonstrates that soaking hay reduces dust exposure.

Association between fungal detection, airways inflammation and diagnosis of moderate to severe asthma in horses.

Equine Asthma Does Not Affect Circulating Myostatin Concentrations in Horses.

The amount of hyaluronic acid and airway remodelling increase with the severity of inflammation in neutrophilic equine asthma.

Serum Vitamin D Level Is Unchanged in Equine Asthma.

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.

Association between equine asthma and fungal elements in the tracheal wash: An environment-matched case-control study.

Protein microarray allergen profiling in bronchoalveolar lavage fluid and serum of horses with asthma.

Molecular and Cellular Evaluation of Horses With Summer Pasture Associated Asthma Syndrome.

Giant Multinucleated Cells Are Associated with Mastocytic Inflammatory Signature Equine Asthma.

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

Some Genetic and Environmental Effects on Equine Asthma in Polish Konik Horses.

Comparison of Four Different Allergy Tests in Equine Asthma Affected Horses and Allergen Inhalation Provocation Test.

Fecal microbiota in horses with asthma.

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.

Impaired Cell Cycle Regulation in a Natural Equine Model of Asthma.

Enhanced IL-6 transcriptional response to adenosine receptor ligands in horses with lower airway inflammation.

Exploring a pico-well based scRNA-seq method (HIVE) for simplified processing of equine bronchoalveolar lavage cells.

Clinical effects and pharmacokinetics of nebulized lidocaine in healthy horses.

Case-Control Study of Risk Factors for Equine Asthma in Texas.

Evaluation of histamine-provoked changes in airflow using electrical impedance tomography in horses.

Abnormalities in lung surfactant in horses clinically affected with recurrent airway obstruction (RAO).

Prevalence and Perceived Effects of Enrichment Elements in Outdoor Areas on the Behavior and Welfare of Group-Housed Horses

Chronic Cough and Hyperpnea: Clinical Approach to Equine Asthma.

Respiratory extracellular vesicle isolation optimization through proteomic profiling of equine samples and identification of candidates for cell-of-origin studies.

Artificial intelligence in smartphone video analysis for equine asthma diagnostic support.

Antimicrobial Prescription Behavior in Equine Asthma Cases: An International Survey.

Cytokine mRNA expression in the bronchoalveolar lavage cells from horses affected by different equine asthma subtypes.

The Microbiota and Equine Asthma: An Integrative View of the Gut-Lung Axis.

Equine Asthma Diagnostics: Review of Influencing Factors and Difficulties in Diagnosing Subclinical Disease.

Towards personalized medicine for the treatment of equine asthma.

The Most Common Environmental Risk Factors for Equine Asthma-A Narrative Review.

Survey of the knowledge and perceptions of horse owners in Ireland of common clinical conditions and their impact.

Investigation of nasal epithelial cells as a surrogate for bronchial epithelial cells in the research of equine asthma.

Withaferin A Inhibits Neutrophil Adhesion, Migration, and Respiratory Burst and Promotes Timely Neutrophil Apoptosis.

The Usefulness of Mesenchymal Stem Cells beyond the Musculoskeletal System in Horses.

Glucocorticoid treatment in horses with asthma: A narrative review.

Equine Asthma: Current Understanding and Future Directions.

The Potential of Mesenchymal Stem Cells to Treat Systemic Inflammation in Horses.

Equine bronchial fibroblasts enhance proliferation and differentiation of primary equine bronchial epithelial cells co-cultured under air-liquid interface.

Understanding Recurrent Airway Obstruction (RAO) in the Horse

Genes and respiratory disease: a first step on a long journey.

Effect of Hay Steaming on the Estimated Precaecal Digestibility of Crude Protein and Selected Amino Acids in Horses.

Recellularization of Bronchial Extracellular Matrix With Primary Bronchial Smooth Muscle Cells.