FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Equine veterinary journal2025; doi: 10.1111/evj.70002

Endoscopically assessed mucus parameters in equine asthma: Relationship to clinical history and cytological findings data.

Abstract: Mucus parameters are hallmark diagnostic features of equine asthma (EA). Objective: To investigate the relationship between mucus quantity score and mucus viscosity score with signalment, history, clinical findings and cytological parameters. Methods: Retrospective cross-sectional study. Methods: Mucus quantity and viscosity scores, signalment, history and clinical findings recorded for diagnostic purposes from up to 1599 samples, and cytological values of the corresponding bronchoalveolar lavage fluid (BALF) and tracheobronchial secretions were analysed. The cut-off value of a mucus quantity score >2 for the diagnosis of mild to moderate EA (MEA) was used to calculate the odds ratios for MEA and severe EA (SEA). Associations were tested via a multivariate Kruskal-Wallis test. The mucus scores were analysed pairwise with cytological characteristics, anamnestic data and clinical signs by testing for independence using the chi-square test. Correlations were evaluated using the non-parametric Spearman's rank correlation coefficient. Results: A mucus quantity score >2 was associated with increased odds of diagnosing SEA (odds ratio 3.6, 95% confidence interval 1.75, 7.17, p < 0.001), but not for MEA. A weak positive correlation was found between neutrophil granulocytes in BALF and mucus quantity score (rho: 0.353, p < 0.001) as well as mucus viscosity score (rho: 0.225, p < 0.001). The mucus scores for quantity and viscosity were significantly associated (p < 0.001) with age, respiratory rate and arterial oxygen partial pressure values, and significantly associated (p < 0.001) with season, type of nasal discharge and respiratory pattern. However, no associations were found with body condition score (BCS), sex and breed. Conclusions: This was a convenience sample with a cytologically unremarkable control group, but no healthy control group. Conclusions: Mucus quantity score is a diagnostic parameter for the diagnosis of SEA. Associations between mucus scores and neutrophilic influx and with some clinical parameters were identified, while there was no confirmed relationship to BCS. Unassigned: Schleimparameter sind charakteristische Merkmale und indikative diagnostische Komponenten von Equinem Asthma (EA). Unassigned: Querschnittsstudie zur Untersuchung der Verhähltnisse zwischen dem Mucus Quantity Score (m.q.) und dem Mucus Viscosity Score (m.v.) und Signalement, Anamnese, klinischen Befunden und zytologischen Parametern. Methods: Retrospektive Querschnittsstudie. Methods: Analysiert wurden die Schleimmenge und Viskositätswerte, das Signalement, die Anamnese und klinischen Befunde, die zu Diagnosezwecken von bis zu 1599 Proben erfasst wurden, sowie die zytologischen Werte der entsprechenden bronchoalveolären Lavagflüssigkeit (BALF) und tracheobronchialen Sekrete (TBS). Der Cut‐off‐Wert eines Mucus Quantity Score >2 für die Diagnose eines leichten bis mittelschweren EA (MEA) wurde für die Berechnung der Odds Ratios für MEA und schweres EA (SEA) verwendet. Assoziationen wurden mittels eines multivariaten Kruskall‐Wallis‐Tests geprüft. Die Mucus‐Scores wurden paarweise mit zytologischen Merkmalen, anamnestischen Daten und klinischen Symptomen analysiert, indem die Unabhängigkeit mit dem Chi‐Square‐Test geprüft wurde. Korrelationen wurden mit dem nichtparametrischen Spearman‐Rangkorrelationskoeffizienten bewertet. Unassigned: Ein Mucus Quantity Score > 2 war mit einer 3,6‐fachen [OR 3,6, 95% 1,75, 7,17, p < 0,001] statistisch signifikant erhöhten Wahrscheinlichkeit verbunden, ein SEA zu diagnostizieren, aber nicht für ein MEA. Eine schwache positive Korrelation wurde zwischen neutrophilen Granulozyten in der BALF und des Mucus Quantity Score (rho: 0,353; p < 0,001) sowie dem Mucus Viscosity Score (rho: 0,225; p < 0,001) festgestellt. Darüber hinaus waren die Schleimwerte Mucus Quantity Score und Mucus Viscosity Score signifikant (p < 0,001) mit Alter, Atemfrequenz und arteriellen Sauerstoffpartialdruckwerten sowie signifikant (p < 0,001) mit Jahreszeit, Art des Nasenausflusses und Atmungsmuster verbunden. Es wurden jedoch keine Zusammenhänge mit dem Body Condition Score (BCS), dem Geschlecht und der Rasse festgestellt. HAUPTEINSCHRÄNKUNGEN: Es handelte sich um eine Zufallsstichprobe mit einer “zytologisch unauffälligen” Kontrollgruppe, aber ohne eine gesunke Kontrollgruppe. Unassigned: Der Mucus Quantity Score ist ein diagnosticher Parameter für die Diagnose von SEA. Aossiziationen zwischen Mucus‐Scores und neutrophilem Einstrom sowie manchen klinischen Parametern wurden identifiziert, während eine Beziehung zum BCS nicht bestätigt werden konnte.
© 2025 The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
Get Full Text
Publication Date: 2025-07-24 PubMed ID: 40704584DOI: 10.1111/evj.70002Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research investigates the relationship between mucus parameters, such as quantity and viscosity, and various factors such as history, clinical findings, and cytological parameters in horses diagnosed with equine asthma. The study finds that higher mucus quantity scores are associated with diagnosing severe equine asthma, neutrophilic influx and several clinical parameters. However, they found no association with the animal’s body condition score, sex, and breed.

Objective and Methods

  • The goal of the study was to analyse the connection between mucus quantity and viscosity scores with signalment, history, clinical findings, and cytological parameters in horses diagnosed with equine asthma (EA).
  • The researchers conducted a retrospective cross-sectional study and worked on data from up to 1599 samples, extracted for diagnostic purposes.
  • The samples included mucus score, signalment, history, and clinical findings, as well as cytological values of the corresponding bronchoalveolar lavage fluid (BALF) and tracheobronchial secretions.

Analysis and Results

  • Analysis was done using the multivariate Kruskal-Wallis test, chi-square test for independence, and Spearman’s rank correlation coefficient.
  • The mucus quantity score >2 showed increased odds of diagnosing severe EA (SEA), indicating that high mucus quantity was indicative of severe asthma conditions.
  • A weak positive link was observed between the quantity and viscosity of mucus and the presence of neutrophil granulocytes in BALF.
  • Furthermore, mucus quantity and viscosity scores were significantly related to age, respiratory rate, and arterial oxygen partial pressure values, along with the type of nasal discharge, respiratory pattern, and season.
  • However, no relationship was established with the body condition score, sex, and breed of the horse.

Limitations and Conclusions

  • The study was based on a convenience sample and did not include a healthy control group.
  • This study concludes that mucus quantity is an important diagnostic parameter for severe EA.
  • Associations were confirmed between mucus scores and neutrophilic influx as well as some clinical parameters. But, there was no confirmed relationship with the body condition score.

Cite This Article

APA
Drespling J, Berwanger L, Kühn H, Schwarz B, Doherr M, Mundhenk L. (2025). Endoscopically assessed mucus parameters in equine asthma: Relationship to clinical history and cytological findings data. Equine Vet J. https://doi.org/10.1111/evj.70002

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Drespling, Julia
  • Institute of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany.
  • EquiZyt UG Laboratory, Steinhöring, Germany.
Berwanger, Leonie
  • Institute of Veterinary Epidemiology and Biostatistics, Freie Universität Berlin, Berlin, Germany.
Kühn, Heike
  • EquiZyt UG Laboratory, Steinhöring, Germany.
Schwarz, Bianca
  • EquiZyt UG Laboratory, Steinhöring, Germany.
Doherr, Marcus
  • Institute of Veterinary Epidemiology and Biostatistics, Freie Universität Berlin, Berlin, Germany.
Mundhenk, Lars
  • Institute of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany.

Grant Funding

  • MU 3015/3-1 / Deutsche Forschungsgemeinschaft

References

This article includes 53 references
  1. Couëtil LL, Cardwell JM, Gerber V, Lavoie JP, Léguillette R, Richard EA. Inflammatory airway disease of horses—revised consensus statement. J Vet Intern Med 2016;30(2):503–1515.
    doi: 10.1111/jvim.13824google scholar: lookup
  2. Hill DB, Button B, Rubinstein M, Boucher RC. Physiology and pathophysiology of human airway mucus. Physiol Rev 2022;102(4):1757–1836.
    doi: 10.1152/physrev.00004.2021google scholar: lookup
  3. Fahy JV, Dickey BF. Airway mucus function and dysfunction. N Engl J Med 2010;363(23):2233–2247.
    doi: 10.1056/nejmra0910061google scholar: lookup
  4. Rogers DF. Physiology of airway mucus secretion and pathophysiology of hypersecretion. Respir Care 2007;52(9):1134–1146; discussion 1146–1149.
  5. Bartner LR, Robinson NE, Kiupel M, Tesfaigzi Y. Persistent mucus accumulation: a consequence of delayed bronchial mucous cell apoptosis in RAO‐affected horses?. Am J Physiol Lung Cell Mol Physiol 2006;291(4):L602–L609.
    doi: 10.1152/ajplung.00500.2005google scholar: lookup
  6. Gerber V, Lindberg Å, Berney C, Robinson NE. Airway mucus in recurrent airway obstruction—short‐term response to environmental challenge. J Vet Intern Med 2004;18(1):92–97.
    doi: 10.1111/j.1939-1676.2004.tb00140.xgoogle scholar: lookup
  7. Dixon PM. Respiratory mucociliary clearance in the horse in health and disease, and its pharmaceutical modification. Vet Rec 1992;131(11):229–235.
    doi: 10.1136/vr.131.11.229google scholar: lookup
  8. Robinson NE, Berney C, Eberhart S, deFeijter‐Rupp HL, Jefcoat AM, Cornelisse CJ. Coughing, mucus accumulation, airway obstruction, and airway inflammation in control horses and horses affected with recurrent airway obstruction. Am J Vet Res 2003;64(5):550–557.
    doi: 10.2460/ajvr.2003.64.550google scholar: lookup
  9. Morini M, Gobbo F, Rinnovati R, Romagnoli N, Peli A, Massarenti C. Bronchoalveolar lavage cytology in severe equine asthma: cytocentrifugated versus sediment smear preparations. Vet Sci 2023;10(8):527.
    doi: 10.3390/vetsci10080527google scholar: lookup
  10. Bond S, Léguillette R, Richard EA, Couetil L, Lavoie JP, Martin JG. Equine asthma: integrative biologic relevance of a recently proposed nomenclature. J Vet Intern Med 2018;32(6):2088–2098.
    doi: 10.1111/jvim.15302google scholar: lookup
  11. Gerber V, Straub R, Marti E. Endoscopic scoring of mucus quantity and quality: observer and horse variance and relationship to inflammation, mucus viscoelasticity and volume. Equine Vet J 2004;36(7):576–582.
    doi: 10.2746/0425164044864525google scholar: lookup
  12. Koblinger K, Nicol J, McDonald K, Wasko A, Logie N, Weiss M. Endoscopic assessment of airway inflammation in horses. J Vet Intern Med 2011;25(5):1118–1126.
    doi: 10.1111/j.1939-1676.2011.00788.xgoogle scholar: lookup
  13. Holcombe SJ, Robinson NE, Derksen FJ. Effect of tracheal mucus and tracheal cytology on racing performance in Thoroughbred racehorses. Equine Vet J 2006;38(4):300–304.
    doi: 10.2746/042516406777749191google scholar: lookup
  14. Gerber V, Robinson NE, Luethi S, Marti E, Wampfler B, Straub R. Airway inflammation and mucus in two age groups of asymptomatic well‐performing sport horses. Equine Vet J 2003;35(5):491–495.
    doi: 10.2746/042516403775600424google scholar: lookup
  15. Depecker M, Richard EA, Pitel PH, Fortier G, Leleu C, Couroucé‐Malblanc A. Bronchoalveolar lavage fluid in Standardbred racehorses: influence of unilateral/bilateral profiles and cut‐off values on lower airway disease diagnosis. Vet J 2014;199(1):150–156.
    doi: 10.1016/j.tvjl.2013.10.013google scholar: lookup
  16. Richard EA, Fortier GD, Pitel PH, Dupuis MC, Valette JP, Art T. Sub‐clinical diseases affecting performance in Standardbred trotters: diagnostic methods and predictive parameters. Vet J 2010;184(3):282–289.
    doi: 10.1016/j.tvjl.2009.04.016google scholar: lookup
  17. Holcombe SJ, Jackson C, Gerber V. Stabling is associated with airway inflammation in young Arabian horses. Equine Vet J 2001;33(3):244–249.
    doi: 10.2746/042516401776249606google scholar: lookup
  18. Koch C, Straub R, Ramseyer A, Widmer A, Robinson NE, Gerber V. Endoscopic scoring of the tracheal septum in horses and its clinical relevance for the evaluation of lower airway health in horses. Equine Vet J 2007;39(2):107–112.
    doi: 10.2746/042516407x158764google scholar: lookup
  19. Christley RM, Hodgson DR, Rose RJ, Hodgson JL, Wood JLN, Reid SWJ. Coughing in thoroughbred racehorses: risk factors and tracheal endoscopic and cytological findings. Vet Rec 2001;148(4):99–104.
    doi: 10.1136/vr.148.4.99google scholar: lookup
  20. Cardwell JM, Smith KC, Wood JLN, Newton JR. Infectious risk factors and clinical indicators for tracheal mucus in British National Hunt racehorses. Equine Vet J 2014;46(2):150–155.
    doi: 10.1111/evj.12109google scholar: lookup
  21. Thomas SJ, de Solis CN, Coleman MC. Case‐control study of risk factors for equine asthma in Texas. J Equine Vet Sci 2021;103:103644.
    doi: 10.1016/j.jevs.2021.103644google scholar: lookup
  22. Chowdhury NU, Guntur VP, Newcomb DC, Wechsler ME. Sex and gender in asthma. Eur Respir Rev 2021;30(162):210067.
    doi: 10.1183/16000617.0067-2021google scholar: lookup
  23. Silveyra P, Fuentes N, Rodriguez Bauza D. Sex and gender differences in lung disease. Adv Exp Med Biol 2021;1304:227–258.
    doi: 10.1007/978-3-030-68748-9_14google scholar: lookup
  24. Harvey BJ, McElvaney NG. Sex differences in airway disease: estrogen and airway surface liquid dynamics. Biol Sex Differ 2024;15:56.
    doi: 10.1186/s13293-024-00633-zgoogle scholar: lookup
  25. Gerber V, King M, Schneider DA, Robinson NE. Tracheobronchial mucus viscoelasticity during environmental challenge in horses with recurrent airway obstruction. Equine Vet J 2000;32(5):411–417.
    doi: 10.2746/042516400777591183google scholar: lookup
  26. Vasconcellos CA, Allen PG, Wohl ME, Drazen JM, Janmey PA, Stossel TP. Reduction in viscosity of cystic fibrosis sputum in vitro by gelsolin. Science 1994;263(5149):969–971.
    doi: 10.1126/science.8310295google scholar: lookup
  27. Klier J, Fuchs S, Winter G, Gehlen H. Inhalative nanoparticulate CpG immunotherapy in severe equine asthma: an innovative therapeutic concept and potential animal model for human asthma treatment. Animals 2022;12(16):2087.
    doi: 10.3390/ani12162087google scholar: lookup
  28. Leclere M, Lavoie‐Lamoureux A, Lavoie JP. Heaves, an asthma‐like disease of horses. Respirology 2011;16(7):1027–1046.
    doi: 10.1111/j.1440-1843.2011.02033.xgoogle scholar: lookup
  29. Brehm W, Gehlen H, Ohnesorge B, editors. Handbuch pferdepraxis. In: Vollständig überarbeitete und erweiterte Auflage. 4th ed. Stuttgart: Enke Verlag; 2017.. .
  30. Herholz C, Straub R, Gerber V, Wampfler B, Lüthi S, Imhof A. Relationship between clinical signs and pulmonary function estimated by the single breath diagram for CO2 (SBD‐CO2) in horses with chronic obstructive pulmonary disease. Vet J 2002;163(2):187–195.
    doi: 10.1053/tvjl.2001.0646google scholar: lookup
  31. Henneke DR, Potter GD, Kreider JL, Yeates BF. Relationship between condition score, physical measurements and body fat percentage in mares. Equine Vet J 1983;15(4):371–372.
    doi: 10.1111/j.2042-3306.1983.tb01826.xgoogle scholar: lookup
  32. Leclere M, Desnoyers M, Beauchamp G, Lavoie JP. Comparison of four staining methods for detection of mast cells in equine bronchoalveolar lavage fluid. J Vet Intern Med 2006;20(2):377–381.
    doi: 10.1892/0891-6640(2006)20[377:cofsmf]2.0.co;2google scholar: lookup
  33. Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. New York: Routledge; 1988.. .
    doi: 10.4324/9780203771587google scholar: lookup
  34. Meiseberg LK, Delarocque J, de Buhr N, Ohnesorge B. Clinical variability of equine asthma phenotypes and analysis of diagnostic steps in phenotype differentiation. Acta Vet Scand 2024;66:51.
    doi: 10.1186/s13028-024-00773-7google scholar: lookup
  35. Wysocka B, Kluciński W. Cytological evaluation of tracheal aspirate and broncho‐alveolar lavage fluid in comparison to endoscopic assessment of lower airways in horses with recurrent airways obstruction or inflammatory airway disease. Pol J Vet Sci 2015;18(3):587–597.
    doi: 10.1515/pjvs-2015-0076google scholar: lookup
  36. Couetil L, Cardwell JM, Leguillette R, Mazan M, Richard E, Bienzle D. Equine asthma: current understanding and future directions. Front Vet Sci 2020;7:450.
    doi: 10.3389/fvets.2020.00450google scholar: lookup
  37. Fanta CH. Clinical aspects of mucus and mucous plugging in asthma. J Asthma Off J Assoc Care Asthma 1985;22(6):295–301.
    doi: 10.3109/02770908509087113google scholar: lookup
  38. Nadel JA, Takeyama K, Agusti C. Role of neutrophil elastase in hypersecretion in asthma. Eur Respir J 1999;13(1):190–196.
    doi: 10.1034/j.1399-3003.1999.13a35.xgoogle scholar: lookup
  39. Fischer B, Voynow J. Neutrophil elastase induces MUC5AC messenger RNA expression by an oxidant‐dependent mechanism. Chest 2000;117(5 Suppl 1):317S–320S.
    doi: 10.1378/chest.117.5_suppl_1.317sgoogle scholar: lookup
  40. Ivester KM, Couëtil LL, Moore GE. An observational study of environmental exposures, airway cytology, and performance in racing thoroughbreds. J Vet Intern Med 2018;32(5):1754–1762.
    doi: 10.1111/jvim.15226google scholar: lookup
  41. Dauvillier J, Ter Woort F, Van Erck‐Westergren E. Fungi in respiratory samples of horses with inflammatory airway disease. J Vet Intern Med 2019;33(2):968–975.
    doi: 10.1111/jvim.15397google scholar: lookup
  42. Dély S, Gerber V, Peters LM, Sage SE. Association between equine asthma and fungal elements in the tracheal wash: an environment‐matched case‐control study. PLoS One 2024;19(9):e0309835.
    doi: 10.1371/journal.pone.0309835google scholar: lookup
  43. Robinson NE, Karmaus W, Holcombe SJ, Carr EA, Derksen FJ. Airway inflammation in Michigan pleasure horses: prevalence and risk factors. Equine Vet J 2006;38(4):293–299.
    doi: 10.2746/042516406777749281google scholar: lookup
  44. Dixon PM, Railton DI, McGorum BC. Equine pulmonary disease: a case control study of 300 referred cases. Part 2: details of animals and of historical and clinical findings. Equine Vet J 1995;27(6):422–427.
    doi: 10.1111/j.2042-3306.1995.tb04422.xgoogle scholar: lookup
  45. MacNamara B, Bauer S, Iafe J. Endoscopic evaluation of exercise‐induced pulmonary hemorrhage and chronic obstructive pulmonary disease in association with poor performance in racing Standardbreds. J Am Vet Med Assoc 1990;196(3):443–445.
  46. Liu Y, Zheng J, Zhang HP, Zhang X, Wang L, Wood L. Obesity‐associated metabolic signatures correlate to clinical and inflammatory profiles of asthma: a pilot study. Allergy Asthma Immunol Res 2018;10(6):628–647.
    doi: 10.4168/aair.2018.10.6.628google scholar: lookup
  47. Peters U, Dixon A, Forno E. Obesity and asthma. J Allergy Clin Immunol 2018;141(4):1169–1179.
    doi: 10.1016/j.jaci.2018.02.004google scholar: lookup
  48. Mohan A, Grace J, Wang BR, Lugogo N. The effects of obesity in asthma. Curr Allergy Asthma Rep 2019;19(10):49.
    doi: 10.1007/s11882-019-0877-zgoogle scholar: lookup
  49. Tooba R, Wu TD. Obesity and asthma: a focused review. Respir Med 2022;204:107012.
    doi: 10.1016/j.rmed.2022.107012google scholar: lookup
  50. Hansen S, Honoré ML, Riihimaki M, Pringle J, Ammentorp AH, Fjeldborg J. Seasonal variation in tracheal mucous and bronchoalveolar lavage cytology for adult clinically healthy stabled horses. J Equine Vet Sci 2018;71:1–5.
    doi: 10.1016/j.jevs.2018.09.001google scholar: lookup
  51. Lo Feudo CM, Stucchi L, Conturba B, Stancari G, Zucca E, Ferrucci F. Medical causes of poor performance and their associations with fitness in Standardbred racehorses. J Vet Intern Med 2023;37(4):1514–1527.
    doi: 10.1111/jvim.16734google scholar: lookup
  52. Morris EA, Seeherman HJ. Clinical evaluation of poor performance in the racehorse: the results of 275 evaluations. Equine Vet J 1991;23(3):169–174.
    doi: 10.1111/j.2042-3306.1991.tb02749.xgoogle scholar: lookup
  53. Robins TJ, Bedenice D, Mazan M. A longitudinal analysis of equine asthma presentation and response to treatment using lung function testing and BAL cytology analysis in combination with owner perception. Animals 2023;13(21):3387.
    doi: 10.3390/ani13213387google scholar: lookup

Citations

This article has been cited 1 times.
  1. Bartenschlager F, Kuropka B, Schmitz P, Dumke F, Landmann K, Gruber AD, Weise C, Schnabel CL, Gehlen H, Mundhenk L. Proteomic profiling of equine airway mucus reveals compositional changes in asthmatic phenotypes. Sci Rep 2026 Feb 10;16(1):5880.
    doi: 10.1038/s41598-026-38766-3pubmed: 41667845google scholar: lookup
Subscribe to our newsletter
Join 99,911 horse owners like you who receive our email updates on horse health and nutrition.