1
|
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 2022; 37:338-348. [PMID: 36478588 PMCID: PMC9889630 DOI: 10.1111/jvim.16598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Racehorses commonly develop evidence of mild asthma in response to dust exposure. Diets deficient in omega-3 polyunsaturated fatty acids (Ω-3) might exacerbate this response. HYPOTHESIS To compare dust exposure, bronchoalveolar lavage fluid (BALF) cytology, and plasma Ω-3 and specialized pro-resolving mediators (SPM) concentrations amongst racehorses fed dry hay, steamed hay, and haylage. ANIMALS Forty-three Thoroughbred racehorses. METHODS Prospective clinical trial. Horses were randomly assigned to be fed dry hay, steamed hay, or haylage for 6 weeks. Measures of exposure to dust in the breathing zone were obtained twice. At baseline, week-3, and week-6, BALF cytology was examined. Plasma lipid profiles and plasma SPM concentrations were examined at baseline and week 6. Generalized linear mixed models examined the effect of forage upon dust exposure, BALF cytology, Ω-3, and SPM concentrations. RESULTS Respirable dust was significantly higher for horses fed hay (least-square mean ± s.e.m. 0.081 ± 0.007 mg/m3 ) when compared with steamed hay (0.056 ± 0.005 mg/m3 , P = .01) or haylage (0.053 ± 0.005 mg/m3 , P < .01). At week 6, BALF neutrophil proportions in horses eating haylage (3.0% ± 0.6%) were significantly lower compared with baseline (5.1 ± 0.7, P = .04) and horses eating hay (6.3% ± 0.8%, P < .01). Plasma eicosapentaenoic acid to arachidonic acid ratios were higher in horses eating haylage for 6 weeks (0.51 ± 0.07) when compared with baseline (0.34 ± 0.05, P < .01) and horses eating steamed (0.24 ± 0.02, P < .01) or dry hay (0.25 ± 0.03, P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE Steamed hay and haylage reduce dust exposure compared with dry hay, but only haylage increased the ratio of anti-inflammatory to pro-inflammatory lipids while reducing BAL neutrophil proportions within 6 weeks.
Collapse
Affiliation(s)
- Carla J. Olave
- Department of Veterinary Clinical Sciences, College of Veterinary MedicinePurdue UniversityWest LafayetteIndianaUSA
| | - Kathleen M. Ivester
- Department of Veterinary Clinical Sciences, College of Veterinary MedicinePurdue UniversityWest LafayetteIndianaUSA
| | - Laurent L. Couetil
- Department of Veterinary Clinical Sciences, College of Veterinary MedicinePurdue UniversityWest LafayetteIndianaUSA
| | - John Burgess
- Department of Nutrition Science, College of Health and Human SciencesPurdue UniversityWest LafayetteIndianaUSA
| | - Jae Hong Park
- School of Health Sciences, College of Health and Human SciencesPurdue UniversityWest LafayetteIndianaUSA
| | - Abhijit Mukhopadhyay
- Department of Veterinary Clinical Sciences, College of Veterinary MedicinePurdue UniversityWest LafayetteIndianaUSA
| |
Collapse
|
2
|
Olave CJ, Ivester KM, Couëtil LL, Franco-Marmolejo J, Mukhopadhyay A, Robinson JP, Park JH. Effects of forages, dust exposure and proresolving lipids on airway inflammation in horses. Am J Vet Res 2021; 83:153-161. [PMID: 34843444 DOI: 10.2460/ajvr.21.08.0126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the role of omega-3 polyunsaturated fatty acids (Ω-3)-derived proresolving lipid mediators (PRLM) in the resolution of mild airway inflammation in horses. ANIMALS 20 horses with mild airway inflammation. PROCEDURES Horses previously eating hay were fed hay pellets (low Ω-3 content; n = 10) or haylage (high Ω-3 content; 9) for 6 weeks. Dust exposure was measured in the breathing zone with a real-time particulate monitor. Bronchoalveolar lavage (BAL) was performed at baseline, week 3, and week 6. The effect of PRLM on neutrophil apoptosis and efferocytosis was examined in vitro. BAL fluid inflammatory cell proportions, apoptosis of circulating neutrophils, efferocytosis displayed by alveolar macrophages, and plasma lipid concentrations were compared between groups fed low and high amounts of Ω-3 by use of repeated measures of generalized linear models. RESULTS Dust exposure was significantly higher with hay feeding, compared to haylage and pellets, and equivalent between haylage and pellets. BAL fluid neutrophil proportions decreased significantly in horses fed haylage (baseline, 11.8 ± 2.4%; week 6, 2.5 ± 1.1%) but not pellets (baseline, 12.1 ± 2.3%; week 6, 8.5% ± 1.7%). At week 6, horses eating haylage had significantly lower BAL neutrophil proportions than those eating pellets, and a significantly lower concentration of stearic acid than at baseline. PRLM treatments did not affect neutrophil apoptosis or efferocytosis. CLINICAL RELEVANCE Despite similar reduction in dust exposure, horses fed haylage displayed greater resolution of airway inflammation than those fed pellets. This improvement was not associated with increased plasma Ω-3 concentrations. Feeding haylage improves airway inflammation beyond that due to reduced dust exposure, though the mechanism remains unclear.
Collapse
Affiliation(s)
- Carla J Olave
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | - Kathleen M Ivester
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | - Laurent L Couëtil
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | | | - Abhijit Mukhopadhyay
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | - J Paul Robinson
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN.,Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN
| | - Jae H Park
- School of Health Sciences, College of Health and Human Sciences, Purdue University, West Lafayette, IN
| |
Collapse
|
3
|
Taylor SD, Ivester KM, Stewart C, Page AE, Horohov DW, Couetil LL. The effect of lower airway inflammation on inflammatory cytokine gene expression in bronchoalveolar lavage fluid and whole blood in racing Thoroughbreds. Vet Immunol Immunopathol 2021; 237:110266. [PMID: 33991760 DOI: 10.1016/j.vetimm.2021.110266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Immunological mechanisms involved in the pathogenesis of mild to moderate equine asthma (MEA) are not completely understood. There are limited data on bronchoalveolar lavage fluid (BALF) and blood inflammatory cytokine profiles in racehorses with MEA, and the effect of racing on inflammatory cytokines is unknown. HYPOTHESIS/OBJECTIVES We hypothesized that inflammatory cytokine gene expression in BALF and resting blood would be higher in racehorses with lower airway inflammation compared to healthy controls, and that gene expression in blood collected immediately post-race would be increased compared to resting blood in racehorses with lower airway inflammation. ANIMALS 38 racing Thoroughbreds (samples: 30 resting blood, 22 post-race BALF, 41 post-race blood). METHODS Prospective observational study. Inflammatory cytokine gene expression was determined in resting blood, post-race BALF and post-race blood from racehorses with lower airway inflammation and controls. RESULTS Lower airway inflammation was diagnosed in 79 % of racehorses (23 % neutrophilic, 67 % mastocytic, and 10 % mixed). There was no difference in gene expression in BALF or resting blood between racehorses with lower airway inflammation and controls. IL-8 gene expression was higher in post-race blood compared to resting peripheral blood, regardless of disease (p = 0052). BALF neutrophil proportions increased with increasing IL-1β gene expression in all sample types (p = 0.0025). BALF mast cell proportions increased with increasing TNF-α gene expression in post-race blood (p = 0.015). CONCLUSIONS AND CLINICAL IMPORTANCE Lower airway inflammation was common in a population of racehorses without respiratory signs or exercise intolerance. Exercise alone increased peripheral blood IL-8 gene expression. Inflammatory cytokine gene expression was not increased in BALF or resting blood in horses with subclinical lower airway inflammation, precluding its diagnostic utility in clinical practice.
Collapse
Affiliation(s)
- Sandra D Taylor
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA.
| | - Kathleen M Ivester
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
| | - Craig Stewart
- Gluck Equine Research Center, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA
| | - Allen E Page
- Gluck Equine Research Center, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA
| | - David W Horohov
- Gluck Equine Research Center, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA
| | - Laurent L Couetil
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
| |
Collapse
|
4
|
Olave CJ, Ivester KM, Couetil LL, Kritchevsky JE, Tinkler SH, Mukhopadhyay A. Dust exposure and pulmonary inflammation in Standardbred racehorses fed dry hay or haylage: A pilot study. Vet J 2021; 271:105654. [PMID: 33840486 DOI: 10.1016/j.tvjl.2021.105654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 02/22/2021] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
Respirable dust exposure is linked to airway inflammation in racehorses. Feeding haylage may reduce dust exposure by 60-70%. The objective of this study was to compare dust exposure, airway cytology, and inflammatory cytokine concentrations between horses fed haylage or hay over 6 weeks while in training. Seven healthy Standardbred horses were randomly assigned to be fed alfalfa hay (n = 3) or grass-alfalfa mix haylage (n = 4) for six weeks while training on a treadmill. Dust exposure was measured gravimetrically at the breathing zone. Endotoxin and β-glucan concentrations in respirable dust were measured. Bronchoalveolar lavage fluid (BALF) cytology was determined at baseline and after 2, 4, and 6 weeks. Cytokine concentrations (interferon-γ, tumor necrosis factor-α, and interleukin-4) were measured in BALF at baseline and week 6. The effect of forage on exposure, airway cytology and cytokines were evaluated using generalized linear mixed models. Respirable dust and β-glucan exposures were lower in horses fed haylage than hay (0.02 ± 0.001 mg/m3 vs. 0.06 ± 0.01 mg/m3; P = 0.03, and 69 ± 18 pg/m3 vs. 160 ± 21 pg/m3; P = 0.02, respectively). In horses eating haylage, BALF neutrophil proportion decreased between baseline (2.2 ± 0.5%), week 2 (0.8 ± 0.3%; P = 0.01) and week 6 (0.7 ± 0.2%; P = 0.03). By week 6, horses fed haylage had lower BALF neutrophilia than horses fed hay (4.0 ± 0.7 %; P = 0.0004). Interleukin-4 concentration in BALF was higher at week 6 (14.4 ± 4.6 pg/mL) in horses fed hay compared to baseline (2.9 ± 4.6 pg/mL; P = 0.007). In conclusion, feeding haylage instead of hay to horses in training can reduce exposure to respirable irritants and mitigate airway neutrophilia.
Collapse
Affiliation(s)
- C J Olave
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison St., West Lafayette, IN 47907, USA
| | - K M Ivester
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison St., West Lafayette, IN 47907, USA
| | - L L Couetil
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison St., West Lafayette, IN 47907, USA.
| | - J E Kritchevsky
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison St., West Lafayette, IN 47907, USA
| | - S H Tinkler
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison St., West Lafayette, IN 47907, USA
| | - A Mukhopadhyay
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison St., West Lafayette, IN 47907, USA
| |
Collapse
|
5
|
Ivester KM, Couëtil LL, Moore GE. An observational study of environmental exposures, airway cytology, and performance in racing thoroughbreds. J Vet Intern Med 2018; 32:1754-1762. [PMID: 30222207 PMCID: PMC6189343 DOI: 10.1111/jvim.15226] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 03/27/2018] [Accepted: 05/03/2018] [Indexed: 12/05/2022] Open
Abstract
Background Mild equine asthma is presumed to arise in response to environmental exposures but the relative impact of differing inflammatory phenotypes upon performance are largely unexplored. Hypotheses: Airway inflammation negatively affects performance and cytological phenotype varies with environmental exposure. Animals Thoroughbred racehorses in active training and racing. Methods Thoroughbreds were recruited 24‐48 hours before racing. Each horse was eligible for re‐enrollment with each race entry. Within one hour of race completion, physical examination, respiratory endoscopy, and BAL were performed. Respirable and inhalable dust, respirable endotoxin, and respirable β‐glucan exposures were measured at the breathing zone within one week after racing. Controlling for age, trainer, and pulmonary hemorrhage, the relationship between performance, bronchoalveolar lavage fluid (BALF) cytology, and measures of exposure were modeled. Results Performance and BALF data were collected on 64 individual horses from 8 stables for a total of 98 race performances and 79 dust exposure assessments. Evidence of mild equine asthma was found in 80% (78/98) of BALF samples from 52/64 horses. For each percent increase in BALF mast cell and neutrophil proportions, speed figures were reduced by 2.9 (P = .012) and 1.4 (P = .046) points, respectively. Respirable dust concentration was associated with BALF neutrophil proportions (P = .015). Bronchoalveolar lavage fluid mast cell proportions were only associated with respirable β‐glucan exposures (P = .030). Conclusions and Clinical Importance: Mild equine asthma is common in racing horses and negatively impacts performance. The data support that respirable, rather than inhalable, dust exposure measures are pertinent to equine airway health.
Collapse
Affiliation(s)
- Kathleen M Ivester
- Department of Veterinary Clinical Sciences, Purdue College of Veterinary Medicine, 625 Harrison Street, West Lafayette, Indiana
| | - Laurent L Couëtil
- Department of Veterinary Clinical Sciences, Purdue College of Veterinary Medicine, 625 Harrison Street, West Lafayette, Indiana
| | - George E Moore
- Department of Veterinary Clinical Sciences, Purdue College of Veterinary Medicine, 625 Harrison Street, West Lafayette, Indiana
| |
Collapse
|
6
|
Arroyo MG, Couëtil LL, Nogradi N, Kamarudin MM, Ivester KM. Efficacy of Inhaled Levalbuterol Compared to Albuterol in Horses with Recurrent Airway Obstruction. J Vet Intern Med 2016; 30:1333-7. [PMID: 27282625 PMCID: PMC5089594 DOI: 10.1111/jvim.14320] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 04/25/2016] [Accepted: 05/10/2016] [Indexed: 11/30/2022] Open
Abstract
Background The (R)‐enantiomer of racemic albuterol (levalbuterol) has bronchodilatory properties whereas the (S)‐enantiomer causes adverse effects in human airways, animal models, and isolated equine bronchi. Levalbuterol is commercially available and improves pulmonary function of asthmatic patients with a longer duration of effect than albuterol. Objective To determine the dose at which inhaled levalbuterol produces maximal bronchodilatory effect (EDmax) and determine its duration of action in recurrent airway obstruction (RAO)‐affected horses in comparison to racemic albuterol. Animals Nine horses with inducible and reversible RAO. Methods Randomized, crossover trial. Horses were challenged with moldy hay to induce airway obstruction. Horses were treated with nebulized albuterol or levalbuterol chosen randomly. Pulmonary function testing (PFT) was measured before and for up to 3 hours after bronchodilatation challenge. Maximum change in transpulmonary pressure (DPmax) was measured to assess the dose effect and duration of action of each drug. After a 24 hours washout period, the bronchodilatation challenge was repeated with the second bronchodilator. Results The duration of effect was 60 minutes for albuterol and 120 minutes for levalbuterol. The dose of bronchodilator EDmax was not significantly different between albuterol and levalbuterol (EDmax = 125.0 [125–125 μg] and EDmax = 188 [125–188 μg] respectively; P = .068). The magnitude of bronchodilatation was not significantly different between the 2 treatments (61.1 and 59.9% decrease in DPmax for albuterol and levalbuterol respectively; P = .86). Conclusions and clinical importance Levalbuterol is as effective a bronchodilator as albuterol; although levalbuterol lasts twice as long as albuterol, its duration of action is still too short to make it practical for RAO treatment.
Collapse
Affiliation(s)
- M G Arroyo
- Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN
| | - L L Couëtil
- Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN
| | - N Nogradi
- Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN
| | - M M Kamarudin
- Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN
| | - K M Ivester
- Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN
| |
Collapse
|
7
|
Ivester KM, Couëtil LL, Zimmerman NJ. Investigating the link between particulate exposure and airway inflammation in the horse. J Vet Intern Med 2014; 28:1653-65. [PMID: 25273818 PMCID: PMC4895611 DOI: 10.1111/jvim.12458] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/25/2014] [Accepted: 08/20/2014] [Indexed: 01/30/2023] Open
Abstract
Inhalant exposure to airborne irritants commonly encountered in horse stables is implicated in the pathogenesis of inflammatory airway disease (IAD) and recurrent airway obstruction (RAO), non‐infectious, inflammatory pulmonary disorders that impact the health and performance of horses across all equine disciplines. IAD and RAO have overlapping clinical, cytological, and functional manifestations of the pulmonary response to organic dust and noxious gases encountered in the barn environment. Study of these diseases has provided important but incomplete understanding of the effect of air quality upon the respiratory health of horses. In this review, the principles of particulate exposure assessment, including health‐related aerosol size fractions and size‐selective sampling, the factors influencing air quality in equine environments, and the effect of air quality on the equine respiratory tract are discussed. The objective of this review is to provide the reader with a summary of the most common chronic inflammatory airway diseases in the horse and the principles of air sampling that are essential to the planning, interpretation, and assessment of equine respiratory health‐related exposure studies.
Collapse
Affiliation(s)
- K M Ivester
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN
| | | | | |
Collapse
|
8
|
Ivester KM, Couëtil LL, Moore GE, Zimmerman NJ, Raskin RE. Environmental exposures and airway inflammation in young thoroughbred horses. J Vet Intern Med 2014; 28:918-24. [PMID: 24773603 PMCID: PMC4895475 DOI: 10.1111/jvim.12333] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 12/06/2013] [Accepted: 01/21/2014] [Indexed: 01/13/2023] Open
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 rs = 0.37, P = .012, 28 days in training, rs = 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.
Collapse
Affiliation(s)
- K M Ivester
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN
| | | | | | | | | |
Collapse
|
9
|
Abstract
REASONS FOR PERFORMING STUDY Exposure of horses to airborne particulates during stable confinement has been linked with airway inflammation in these animals. Understanding that link requires accurate measures of exposures and greater understanding of the sources of variability in these exposures. OBJECTIVES Area and breathing zone particulate concentrations were measured over time in order to determine the relative variability introduced by daily, monthly or between horse variations. Additionally, the relationship between area and breathing zone respirable particulate concentrations was examined. METHODS The study was conducted in a Thoroughbred training stable. Breathing zone and area respirable particulate concentrations were measured over a 30-month period. Mixed-model analysis of variance was used to determine effect of month and year at the time of sampling and the daily variance upon area particulate concentrations. The effects of hay feeding method and horse variance on breathing zone measures were included in the model. Real-time concentrations of particulate matter with an aerodynamic diameter of 10 microm or smaller (PM10) were measured to determine the effect of barn door position. Significance was set at P < 0.05. RESULTS Average area particulate concentration varied with month and year of sampling but daily variation was not significant. Maximum area respirable particulate concentrations were significantly affected by daily variation. Opening barn doors resulted in lower PM10 levels. Horses fed from hay nets were exposed to significantly higher concentrations of respirable particulates in their breathing zone than when fed hay on the ground. Horse-to-horse variability was significant. Breathing zone concentrations were significantly greater than area concentrations and the 2 measurements were not correlated. CONCLUSIONS While area respirable particulate concentrations reflected seasonal changes, these measures are poor predictors of individual horse exposure. Instead, methods of feeding and individual horse behaviour are important determinants of exposure. POTENTIAL RELEVANCE Studies investigating the effect of natural exposures on lung health in horses should consider the effects of individual behaviour and management practices on breathing zone exposure.
Collapse
Affiliation(s)
- K M Ivester
- Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | | | | | | | | |
Collapse
|
10
|
Bertin FR, Ivester KM, Couëtil LL. Comparative efficacy of inhaled albuterol between two hand-held delivery devices in horses with recurrent airway obstruction. Equine Vet J 2011; 43:393-8. [PMID: 21496081 DOI: 10.1111/j.2042-3306.2010.00313.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
REASONS FOR PERFORMING STUDY Studies investigating the clinical efficacy of albuterol administered with the same propellant and commercially available delivery devices in horses with recurrent airway obstruction (RAO) are not currently available. OBJECTIVES To determine the efficacy of aerosolised albuterol administered to horses with RAO by means of 2 commercially available, hand-held delivery devices. METHODS Ten horses with RAO were kept in a dusty environment and fed mouldy hay to induce airway obstruction. Lung mechanics were measured before and after the procedure. ΔP(max) was measured 5 min after administration of 180 µg of albuterol from a pressurised metered dose inhaler, using an aerosol delivery device chosen randomly. This process was repeated every 5 min until maximal bronchodilation was achieved. After a 24 h washout period, lung mechanics data were again collected using the other aerosol delivery device. RESULTS Aerosolised albuterol induced a significant and rapid bronchodilation in the horses using both aerosol delivery devices. No statistically significant difference in pulmonary function was observed in response to albuterol therapy between the 2 devices. The dose required to achieve 50% of maximal bronchodilation was not statistically different between the 2 devices (173.35 ± 78.35 µg with Device 1 and 228.49 ± 144.99 µg with Device 2, P = 0.26). The decrease in lung resistance tended to be more pronounced after albuterol administration with Device 1 (P = 0.066). CONCLUSIONS Aerosolised albuterol is an effective bronchodilator in horses with recurrent airway obstruction. There is no statistically significant difference between the 2 commercially available aerosol delivery devices in terms of efficacy. POTENTIAL RELEVANCE Aerosolised albuterol is effectively delivered using currently available devices leading to maximal bronchodilation in horses with RAO at an average dose of 540 µg.
Collapse
Affiliation(s)
- F R Bertin
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, Indiana, USA
| | | | | |
Collapse
|
11
|
Ivester KM, Adams SB, Moore GE, Van Sickle DC, Lescun TB. Gentamicin concentrations in synovial fluid obtained from the tarsocrural joints of horses after implantation of gentamicin-impregnated collagen sponges. Am J Vet Res 2006; 67:1519-26. [PMID: 16948595 DOI: 10.2460/ajvr.67.9.1519] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine synovial fluid gentamicin concentrations and evaluate adverse effects on the synovial membrane and articular cartilage of tarsocrural joints after implantation of a gentamicin-impregnated collagen sponge. ANIMALS 6 healthy adult mares. PROCEDURES A purified bovine type I collagen sponge impregnated with 130 mg of gentamicin was implanted in the plantarolateral pouch of 1 tarsocrural joint of each horse, with the contralateral joint used as a sham-operated control joint. Gentamicin concentrations in synovial fluid and serum were determined for 120 hours after implantation by use of a fluorescence polarization immunoassay. Synovial membrane and cartilage specimens were collected 120 hours after implantation and evaluated histologically. RESULTS Median peak synovial fluid gentamicin concentration of 168.9 microg/mL (range, 115.6 to 332 microg/mL) was achieved 3 hours after implantation. Synovial fluid gentamicin concentrations were < 4 microg/mL by 48 hours. Major histologic differences were not observed in the synovial membrane between control joints and joints implanted with gentamicin-impregnated sponges. Safranin-O fast green stain was not reduced in cartilage specimens obtained from treated joints, compared with those from control joints. CONCLUSIONS AND CLINICAL RELEVANCE Implantation of a gentamicin-impregnated collagen sponge in the tarsocrural joint of horses resulted in rapid release of gentamicin, with peak concentrations > 20 times the minimum inhibitory concentration reported for common pathogens that infect horses. A rapid decrease in synovial fluid gentamicin concentrations was detected. The purified bovine type I collagen sponges did not elicit substantial inflammation in the synovial membrane or cause mechanical trauma to the articular cartilage.
Collapse
Affiliation(s)
- Kathleen M Ivester
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | | | | | | | | |
Collapse
|
12
|
Affiliation(s)
- Kathleen M Ivester
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | | | | | | |
Collapse
|