Environmental Exposures and Airway Inflammation in Young Thoroughbred Horses

Journal of Veterinary Internal Medicine

K.M. Ivester²  L.L. Couëtil²  G.E. Moore¹  N.J. Zimmerman³ 

[1] Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine, West Lafayette, IN;Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN;School of Health Sciences (Zimmerman), Purdue University, West Lafayette, IN

关键词: Bronchoalveolar lavage;    Cytology;    Endotoxin;    Eosinophils;    Particulates;   

DOI  :  10.1111/jvim.12333

来源: Wiley

【 摘 要 】

Abstract

Background

Inflammatory airway disease (IAD) in horses is a widespread, performance-limiting syndrome believed to develop in response to inhaled irritants in the barn environment.

Objectives

To evaluate changes in bronchoalveolar lavage fluid (BALF) cytology and exposure to particulates, endotoxin, and ammonia during horses' first month in training.

Animals

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/m³, no hay net 0.055 mg/m³, P < .001). Likewise, inhalable particulate (hay net 8.3 mg/m³, no hay net 3.3 mg/m³, P = .0064) and respirable endotoxin (hay net 173.4 EU/m³, no hay net 59.2 EU/m³, 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 r_s = 0.37, P = .012, 28 days in training, r_s = 0.38, P = .017).

Conclusions and Clinical Importance

Pulmonary eosinophilic inflammation develops in response to respirable particulate exposure in young Thoroughbreds, indicating a potential hypersensitivity to inhaled particulate allergens.

【 授权许可】

Unknown   
Copyright © 2014 by the American College of Veterinary Internal Medicine