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Home / Equine Research Bank / J Vet Intern Med / Environmental exposures and airway inflammation in young tho...
Journal of veterinary internal medicine2014; 28(3); 918-924; doi: 10.1111/jvim.12333

Environmental exposures and airway inflammation in young thoroughbred horses.

Abstract: Inflammatory airway disease (IAD) in horses is a widespread, performance-limiting syndrome believed to develop in response to inhaled irritants in the barn environment. Objective: To evaluate changes in bronchoalveolar lavage fluid (BALF) cytology and exposure to particulates, endotoxin, and ammonia during horses' first month in training. Methods: Forty-nine client-owned 12- to 36-month-old Thoroughbred horses entering race training. Methods: In this prospective cohort study, a convenience sample of horses was assigned to be fed hay from a net (n = 16), whereas the remaining horses were fed hay from the ground (n = 33). BALF was collected at enrollment and after 14 and 28 days in training. Respirable particulate, inhalable particulate, respirable endotoxin, and ammonia concentrations were measured at the breathing zone of each horse weekly. Results: Median respirable particulates were significantly higher when horses were fed from hay nets than when fed hay from the ground (hay net 0.28 mg/m(3) , no hay net 0.055 mg/m(3) , P < .001). Likewise, inhalable particulate (hay net 8.3 mg/m(3) , no hay net 3.3 mg/m(3) , P = .0064) and respirable endotoxin (hay net 173.4 EU/m(3) , no hay net 59.2 EU/m(3) , P = .018) exposures were significantly higher when horses were fed from hay nets. Feeding hay from a net resulted in significantly higher BALF eosinophil proportions over time (P < .001). BALF eosinophils were significantly related to respirable particulate exposure (14 days in training rs = 0.37, P = .012, 28 days in training, rs = 0.38, P = .017). Conclusions: Pulmonary eosinophilic inflammation develops in response to respirable particulate exposure in young Thoroughbreds, indicating a potential hypersensitivity to inhaled particulate allergens.
Copyright © 2014 by the American College of Veterinary Internal Medicine.
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Publication Date: 2014-03-12 PubMed ID: 24773603PubMed Central: PMC4895475DOI: 10.1111/jvim.12333Google Scholar: Lookup
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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.

The research explores the relationship between barn environmental factors such as particulates, endotoxin, and ammonia on the development of Inflammatory Airway Disease (IAD) in young thoroughbred horses. The study found that feeding horses from hay nets resulted in significantly higher bronchoalveolar lavage fluid (BALF) eosinophil proportions over time, pointing to increased airway inflammation due to increased inhalation of particles and endotoxins.

Objective of the Study

  • The primary objective of the study was to assess how the horses’ feeding method (from the ground versus from a hay net) and environmental conditions (particle, endotoxin, and ammonia concentrations) affected the concentration of eosinophils in the bronchoalveolar lavage fluid (BALF) during their first month in training. Eosinophils are white blood cells indicative of inflammation or allergic reactions.

Methodology of the Study

  • The researchers recruited 49 thoroughbred horses, aged between 12 to 36 months, who were entering race training. Of this group, 16 horses were randomly fed hay from a net while the remaining 33 were fed from the ground.
  • The bronchoalveolar lavage fluid (BALF) of these horses was collected at the beginning of the study and then after 14 and 28 days of training. This fluid was tested to determine the concentration of eosinophils, a key marker of airway inflammation.
  • Simultaneously, the researchers measured the concentration of inhalable particulates, respirable particulates, endotoxins and ammonia in the horses’ breathing space every week.

Results of the Study

  • The study revealed that horses fed from a hay net had a significantly higher concentration of inhalable and respirable particulates in their breathing area compared to those fed from the ground. Additionally, the concentration of respirable endotoxin was also significantly higher in horses fed from hay nets.
  • Notably, feeding horses from hay nets resulted in a significant increase in the proportion of eosinophils in the BALF over time, indicating that this method of feeding promotes airway inflammation in young Thoroughbreds.
  • The results also pointed to a significant correlation between the exposure to respirable particulates and the concentration of BALF eosinophils after 14 and 28 days of training.

Conclusion

  • The results of the study suggest that horses fed from hay nets experience increased exposure to respirable particulates, which leads to an increased likelihood of airway inflammation, indicative of a hypersensitivity to inhaled particulate allergens. The findings provide important insights into ways barn management practices can influence horse health and performance, particularly for young Thoroughbreds in their early training days.

Cite This Article

APA
Ivester KM, Couëtil LL, Moore GE, Zimmerman NJ, Raskin RE. (2014). Environmental exposures and airway inflammation in young thoroughbred horses. J Vet Intern Med, 28(3), 918-924. https://doi.org/10.1111/jvim.12333

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English
Volume: 28
Issue: 3
Pages: 918-924

Researcher Affiliations

Ivester, K M
  • Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN.
Couëtil, L L
    Moore, G E
      Zimmerman, N J
        Raskin, R E

          MeSH Terms

          • Ammonia / adverse effects
          • Animals
          • Bronchoalveolar Lavage Fluid / cytology
          • Endotoxins / adverse effects
          • Environmental Exposure / adverse effects
          • Eosinophils
          • Horse Diseases / etiology
          • Horses
          • Inflammation / etiology
          • Inflammation / veterinary
          • Neutrophils
          • Particulate Matter / adverse effects
          • Respiratory Tract Diseases / etiology
          • Respiratory Tract Diseases / veterinary

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          This article has been cited 33 times.
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