Airway mucus in recurrent airway obstruction–short-term response to environmental challenge.
Abstract: Mucus accumulation and neutrophilic inflammation in the airways are hallmarks of heaves. Endoscopically visible mucus accumulations, however, have not been studied during exposure to dusty hay and allergens (ie, environmental challenge). We hypothesized that (1) heaves-affected horses have increased mucus accumulation compared with controls, (2) mucus accumulations increase in heaves-affected horses during environmental challenge, and (3) environmental challenge also induces neutrophilic inflammation and mucus accumulation in control horses. Mucus accumulation was graded endoscopically (mucus grades [MGs] 1-5), and airway inflammation was evaluated by bronchoalveolar lavage fluid (BALF) cytology before (0 hours) and during (6, 24, 48 hours) environmental challenge. Large amounts of mucus (MG 4-5) were specific for heaves-affected horses in this study. Variation among controls was considerable, however, and intermediate grades (MG 2-3) were nonspecific, showing complete overlap between the 2 groups. Median mucus accumulations (25th, 75th percentiles) increased in heaves-affected horses from MG 2.5 (1.5, 3.5) at baseline to MG 3.5 (2.0, 4.0), 4.0 (3.0, 4.0), and 4.0 (4.0, 4.0) at 6, 24, and 48 hours, respectively. MG values did not increase in controls--overall MG 1.0 (1.0, 2.0)--even though controls also showed a moderate increase of BALF neutrophils. Mucus accumulations before and especially after exposure to dust and allergens are increased in heaves-affected horses compared with controls. Healthy controls show considerable variability in mucus accumulation but, despite an influx of neutrophils into the airways, no increase of mucus accumulation after exposure to hay dust.
Publication Date: 2004-02-10 PubMed ID: 14765737DOI: 10.1892/0891-6640(2004)18<92:amirao>2.0.co;2Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
- Research Support
- U.S. Gov't
- Non-P.H.S.
Summary
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The research article investigates the relationship between exposure to environmental allergens and the production of mucus in the airways of horses, specifically those suffering from recurrent airway obstruction (RAO) or ‘heaves’. The study found that horses affected by RAO show significant increase in mucus production following exposure to dusty hay and allergens, compared to healthy horses.
Objective of the Study
- The research aimed to assess the severity of mucus accumulation and inflammation in the airways of horses afflicted with RAO, particularly under exposure to dusty hay and other environmental allergens.
- The study hypothesized that RAO-affected horses show a substantial increase in mucus accumulation compared to healthier counterparts, this accumulation significantly increases following exposure to environmental allergens, and this exposure induces inflammation and mucus accumulation in healthy horses as well.
Methodology and Procedures
- The researchers graded the accumulation of mucus endoscopically on a scale of 1-5 (mucus grades [MGs]), and evaluated airway inflammation through the analysis of bronchoalveolar lavage fluid (BALF) cytology. This was done pre (0 hours) and during (6, 24, 48 hours) allergen exposure.
- A primary characteristic of horses with RAO was large amounts of mucus (MG 4-5).
- Horses unaffected by RAO were also evaluated. Although there was a substantial variation among this group, intermediate grades (MG 2-3) similarly showed an overlap between the two types of horses.
Results and Findings
- The average mucus accumulation increased in horses with RAO from MG 2.5 (hour 0) to MG 3.5 (hour 6), MG 4.0 (hour 24), and MG 4.0 (hour 48).
- In contrast, the mucus grade did not increase in the control group, maintaining an overall MG 1.0, even though these horses also indicated a moderate increase of BALF neutrophils (which shows inflammation).
- The results hence demonstrated that mucus accumulation amplified in RAO-affected horses compared to healthy horses, particularly after exposure to dusty hay and allergens.
- Healthy horses demonstrated considerable variability in mucus accumulation but showed no increase in mucus accumulation following exposure to hay dust, even with the influx of neutrophils into the airways.
Cite This Article
APA
Gerber V, Lindberg A, Berney C, Robinson NE.
(2004).
Airway mucus in recurrent airway obstruction–short-term response to environmental challenge.
J Vet Intern Med, 18(1), 92-97.
https://doi.org/10.1892/0891-6640(2004)18<92:amirao>2.0.co;2 Publication
Researcher Affiliations
- Pulmonary Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824-1314, USA. gerbervi@cvm.msu.edu
MeSH Terms
- Airway Obstruction / physiopathology
- Airway Obstruction / veterinary
- Allergens
- Animals
- Bronchi / metabolism
- Bronchoalveolar Lavage Fluid / cytology
- Bronchoscopy / veterinary
- Case-Control Studies
- Female
- Horse Diseases / physiopathology
- Horses
- Inhalation Exposure
- Male
- Mucus / cytology
- Recurrence
- Respiratory Hypersensitivity / physiopathology
- Respiratory Hypersensitivity / veterinary
Citations
This article has been cited 18 times.- Olave CJ, Ivester KM, Couetil LL, Burgess J, Park JH, Mukhopadhyay A. Effects of low-dust forages on dust exposure, airway cytology, and plasma omega-3 concentrations in Thoroughbred racehorses: A randomized clinical trial.. J Vet Intern Med 2023 Jan;37(1):338-348.
- Pisch C, Wensch-Dorendorf M, Schwarzenbolz U, Henle T, Greef JM, Zeyner A. Effect of Hay Steaming on the Estimated Precaecal Digestibility of Crude Protein and Selected Amino Acids in Horses.. Animals (Basel) 2022 Nov 10;12(22).
- Minuto J, Bedenice D, Ceresia M, Zaghloul I, Böhlke M, Mazan MR. Clinical effects and pharmacokinetics of nebulized lidocaine in healthy horses.. Front Vet Sci 2022;9:984108.
- Mahalingam-Dhingra A, Mazan MR, Bedenice D, Ceresia M, Minuto J, Deveney EF. A CONSORT-guided, randomized, double-blind, controlled pilot clinical trial of inhaled lidocaine for the treatment of equine asthma.. Can J Vet Res 2022 Apr;86(2):116-124.
- Couetil L, Cardwell JM, Leguillette R, Mazan M, Richard E, Bienzle D, Bullone M, Gerber V, Ivester K, Lavoie JP, Martin J, Moran G, Niedźwiedź A, Pusterla N, Swiderski C. Equine Asthma: Current Understanding and Future Directions.. Front Vet Sci 2020;7:450.
- Bond SL, Workentine M, Hundt J, Gilkerson JR, Léguillette R. Effects of nebulized dexamethasone on the respiratory microbiota and mycobiota and relative equine herpesvirus-1, 2, 4, 5 in an equine model of asthma.. J Vet Intern Med 2020 Jan;34(1):307-321.
- Orard M, Hue E, Couroucé A, Bizon-Mercier C, Toquet MP, Moore-Colyer M, Couëtil L, Pronost S, Paillot R, Demoor M, Richard EA. The influence of hay steaming on clinical signs and airway immune response in severe asthmatic horses.. BMC Vet Res 2018 Nov 15;14(1):345.
- Bond S, Léguillette R, Richard EA, Couetil L, Lavoie JP, Martin JG, Pirie RS. Equine asthma: Integrative biologic relevance of a recently proposed nomenclature.. J Vet Intern Med 2018 Nov;32(6):2088-2098.
- Ivester KM, Couëtil LL, Moore GE. An observational study of environmental exposures, airway cytology, and performance in racing thoroughbreds.. J Vet Intern Med 2018 Sep;32(5):1754-1762.
- 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 Mar-Apr;30(2):503-15.
- Ivester KM, Couëtil LL, Zimmerman NJ. Investigating the link between particulate exposure and airway inflammation in the horse.. J Vet Intern Med 2014 Nov-Dec;28(6):1653-65.
- Sarmiento J, Perez B, Morales N, Henriquez C, Vidal L, Folch H, Galecio JS, Morán G. Apoptotic effects of tamoxifen on leukocytes from horse peripheral blood and bronchoalveolar lavage fluid.. Vet Res Commun 2013 Dec;37(4):333-8.
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- Morán G, Folch H, Araya O, Burgos R, Barria M. Detection of reaginic antibodies against Faenia rectivirgula from the serum of horses affected with Recurrent Airway Obstruction by an in vitro bioassay.. Vet Res Commun 2010 Dec;34(8):719-26.
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- Perez-Moreno CI, Couëtil LL, Pratt SM, Ochoa-Acuña HG, Raskin RE, Russell MA. Effect of furosemide and furosemide-carbazochrome combination on exercise-induced pulmonary hemorrhage in Standardbred racehorses.. Can Vet J 2009 Aug;50(8):821-7.
- Anton F, Leverkoehne I, Mundhenk L, Thoreson WB, Gruber AD. Overexpression of eCLCA1 in small airways of horses with recurrent airway obstruction.. J Histochem Cytochem 2005 Aug;53(8):1011-21.
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