Topic:Air Quality
Air quality refers to the presence and concentration of pollutants and particulates in the air that horses breathe. It encompasses a range of environmental factors, including dust, ammonia, mold spores, and other airborne contaminants commonly found in equine environments such as stables and arenas. Poor air quality can impact respiratory health in horses, leading to conditions such as recurrent airway obstruction (RAO) and inflammatory airway disease (IAD). This topic explores the sources and effects of air pollutants on equine respiratory systems and examines management practices aimed at improving air quality in equine facilities. This page compiles peer-reviewed research studies and scholarly articles that investigate the impact of air quality on horse health and performance.
Exposure to chemical pollutants and biological aerosol in indoor facilities for recreational and sport horses. Due to the increasing prevalence of equine non-infectious respiratory disease, the air contamination in equine housing (Stables A-C) and training facilities (indoor riding arenas A - C) was investigated. The aim of the study was to monitor gaseous pollutants, bioaerosols, and dust concentrations at three different sites (stables and riding halls), where different floor materials were used in the riding halls. Methods: Air quality was monitored in housing for horses and in riding halls in terms of dust concentration, the presence of gaseous chemical pollutants, and concentrations of biological ...
Nebulized glycosylated caffeic acid phenylether ester attenuation of environmental particulate-induced airway inflammation in horses. The objective of this study was to determine the extent that nebulized glycosylated caffeic acid phenylether ester-4-O-alpha-D-glucopyranoside (G-CAPE) attenuates particulate-induced airway inflammation in healthy horses. Our hypothesis was that nebulization with G-CAPE would result in improved respiratory scores, higher arterial oxygen partial pressure, and less inflammatory airway infiltrates in horses with induced airway inflammation, compared with untreated controls. Five healthy adult horses were housed inside a climate controlled, closed barn on straw bedding and fed moldy grass hay for...
Characterization of fungal exposure and dectin-1 expression in healthy horses and horses with severe asthma. To quantify dectin-1 expression in bronchoalveolar lavage fluid (BALF), create polyclonal antibodies against equine dectin-1 and localize it in tissues, and quantify fungal exposure in pastured and stabled asthmatic and nonasthmatic horses. Methods: BALF samples from 6 controls and 6 horses with severe asthma. Stored lung and nasal wash samples. Methods: Dectin-1 expression was quantified by quantitative PCR (qPCR). Purified peptide from equine dectin-1 was used to generate polyclonal antibodies and was confirmed with immunological testing. Fungal exposure was quantified in BALF samples by cou...
Bacterial aerosol, particulate matter, and microclimatic parameters in the horse stables in Poland. Keeping horses in good condition requires providing them with living conditions that meet welfare requirements. These animals should be accommodated with suitable space, access to high nutritional fodder and water, and a suitable microclimate in their shelters. When it comes to the environment in the stables, a serious problem is created by particulate matter (PM), which consists of bacteria. PM concentration may be responsible for developing multiple lower respiratory tract diseases in horses, including allergies and recurrent airway obstruction (RAO). In turn, these ailments may lead to decr...
Effects of Bedding Material on Equine Lower Airway Inflammation: A Comparison of Two Peat Beddings, Wood Pellet, and Straw Pellet. The effects of bedding material on air quality are important amongst horses worldwide. Respiratory diseases, especially equine asthma, are highly prevalent with air hygiene playing a major role on the pathophysiology of these diseases. The objective of our study was to investigate the effects of four bedding materials on the respiratory signs, tracheal mucus score, and tracheal wash (TW) and bronchoalveolar lavage fluid (BALF) cytology in healthy adult horses. The study design was a prospective controlled cross-over study, and the subjects were healthy adult riding school horses ( = 32) from a...
Effects of forages, dust exposure and proresolving lipids on airway inflammation in horses. 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. Methods: 20 horses with mild airway inflammation. Methods: 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....
Characterization of indoor arenas through an anonymous survey. Equine farms are building both stables for the horses to live in and additional facilities to train and work horses (Kidd et al., 1997). For many of these farms, an outdoor arena that has an all-weather footing is the first working facility built. During inclement weather the ability to train in the outdoor arenas is inhibited, which in turn means the trainers, riders, and farms lose income as money is only made when horses are working, training, and competing. Indoor arenas allow for horses to continue to be worked no matter the weather conditions. The equine industry contributes a total of $...
Framing Future of Work Considerations through Climate and Built Environment Assessment of Volunteer Work Practices in the United States Equine Assisted Services. The foundation of healthy workplace design is an understanding of work practices. Volunteers comprise the majority of the workforce in care centers using horses to address human health issues. Documentation is lacking on protections for worker well-being in equestrian microenvironments which are known to have the potential for dust exposures. Climate acts as a master variable in equestrian facility design and ventilation usage to address dust and temperature concerns. Using climate as an independent variable, our objective was to characterize space usage, safety, environmental control, and org...
Can bronchoconstriction and bronchodilatation in horses be detected using electrical impedance tomography? Electrical impedance tomography (EIT) generates images of the lungs based on impedance change and was able to detect changes in airflow after histamine challenge in horses. Objective: To confirm that EIT can detect histamine-provoked changes in airflow and subsequent drug-induced bronchodilatation. Novel EIT flow variables were developed and examined for changes in airflow. Methods: Bronchoconstriction was induced using stepwise histamine bronchoprovocation in 17 healthy sedated horses. The EIT variables were recorded at baseline, after saline nebulization (control), at the histamine concentra...
Equine respiratory viruses, airway inflammation and performance in thoroughbred racehorses. Equine asthma is a common cause of poor performance in racehorses but it is unclear if respiratory viruses contribute to its etiology. The objective of the study was to determine if respiratory viruses were associated with clinical signs and bronchoalveolar lavage fluid (BALF) cytology in Thoroughbred racehorses. Equine herpesviruses (EHV-1, 2, 4, 5) and equine rhinitis A and B viruses (ERBV, ERAV) genomes were quantified by qPCR in nasopharyngeal, tracheal, and BALF samples collected after racing. The relationships between virus detection and load and clinical signs, performance, BALF cytolog...
Effects of Bedding Material on Equine Lower Airway Inflammation: A Crossover Study Comparing Peat and Wood Shavings. Bedding materials affect stable air hygiene, and thus the development and exacerbation of equine asthma. There is limited knowledge concerning the effects of different types of bedding material on equine lower airway inflammation. The objective of our study was to investigate the effects of bedding materials on respiratory signs, tracheal mucus score, and lower airway cytology in healthy adult horses. The study design was a prospective controlled study, and the subjects were healthy adult riding school horses (n = 32) from a single stable. Wood shavings were compared to peat, which was used as...
Dust exposure and pulmonary inflammation in Standardbred racehorses fed dry hay or haylage: A pilot study. 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 ...
Ex vivo modeling of the airflow dynamics and two-and three-dimensional biomechanical effects of suture placements for prosthetic laryngoplasty in horses. To identify the degree of left arytenoid cartilage (LAC) abduction that allows laryngeal airflow similar to that in galloping horses, assess 2-D and 3-D biomechanical effects of prosthetic laryngoplasty on LAC movement and airflow, and determine the influence of suture position through the muscular process of the arytenoid cartilage (MPA) on these variables. Methods: 7 equine cadaver larynges. Methods: With the right arytenoid cartilage maximally abducted and inspiratory airflow simulated by vacuum, laryngeal airflow and translaryngeal pressure and impedance were measured at 12 incremental LAC...
Increased Weekly Mean PM2.5, and NO2 Are Associated With Increased Proportions of Lower Airway Granulocytes in Ontario Horses. Ambient pollution is associated with the development and exacerbation of human asthma, but whether air pollution exposure is associated with lower airway inflammation in horses has not been fully evaluated. The Air Quality Health Index (AQHI) is an online tool used by asthmatic Ontarians to modify their outdoor activity when ambient pollution is high. A single AQHI value, falling on a scale from 1 to 10, is calculated from measurements of fine particulate matter (PM), nitrogen dioxide (NO), and ozone (O). Increased AQHI values predict an increased risk for presenting to a health care provider ...
Environmental surveillance and adverse neonatal health outcomes in foals born near unconventional natural gas development activity. Studies of neonatal health risks of unconventional natural gas development (UNGD) have not included comprehensive assessments of environmental chemical exposures. We investigated a clustering of dysphagic cases in neonatal foals born between 2014 and 2016 in an area of active UNGD in Pennsylvania (PA),USA. We evaluated equine biological data and environmental exposures on the affected PA farm and an unaffected New York (NY) farm owned by the same proprietor. Dams either spent their entire gestation on one farm or moved to the other farm in late gestation. Over the 21-month study period, physic...
Owner Compliance to an Environmental Management Protocol for Severe Equine Asthma Syndrome. Severe equine asthma (SEA) syndrome is a chronic recurrent respiratory disease, common among adult horses. The disease occurs in genetically susceptible individuals after their exposure to organic dust. Thus, environmental management has proved essential in controlling airway challenge and disease exacerbation. This is a demanding process that can only be achieved through the horse owners' cooperation. One year after initial diagnosis of SEA in a group of 39 horses, owner compliance to an environmental management protocol was evaluated. The overall compliance to the protocol was poor and the h...
Efficacy of dexamethasone, salbutamol, and reduced respirable particulate concentration on aerobic capacity in horses with smoke-induced mild asthma. Mild asthma in horses decreases racing performance and impairs gas exchange. The efficacy of treatment on performance is unknown. Objective: Treatment targeting lung inflammation improves V ˙ O2 peak in horses with mild asthma. Methods: Thoroughbred polo horses (n = 12) with smoke-induced mild asthma. Horses were exposed to increased ambient particulate matter (35.51 μg/m3 [PM2.5 ]; day mean, centrally measured) from day -33 to 0, from bushfire smoke (natural model). Methods: Prospective, randomized, placebo-controlled, double-blinded clinical trial. All horses completed 3 V ˙ O2 peak t...
Science-in-brief: Latex in riding arenas and racetracks identified as a risk factor for equine respiratory health. This study investigates severe equine asthma (sEA), a significant health risk in horses similar to human asthma, identifying latex found in riding arenas and racetracks as a potential risk factor. […]
Inhalable and Respirable Particulate and Endotoxin Exposures in Kentucky Equine Farms. Adverse respiratory health effects in the agricultural industry have been linked to particulate endotoxin exposure. However, whether the endotoxin concentration is significantly correlated to the size of the particle remains an open question. To date, limited research has been conducted to assess particulate endotoxin exposures in the agricultural industry in general or the equine industry in particular. A task-based exposure assessment was conducted to characterize the endotoxin levels of inhalable and respirable particles on four Kentucky farms during the summer season. We conducted personal...
Determination of the Moisture Content and the Generation of Airborne Particulate Matter From Various Types of Footing From Indoor Riding Arenas Considered to Have Optimal Rideability. It has been known for some years now that the occurrence of lameness in horses is closely related to the characteristics of the riding surface and that respiratory tract diseases can be induced by airborne particles. To ensure both optimal rideability (e.g., grip, elasticity, etc.) and low dust production, riding surfaces have to be regularly attended to, which also includes watering the floor. However, at present, it is not known what the individual moisture content of the various types of riding surface should be to ensure optimal rideability or what their potential for releasing dust is at ...
Deoxynivalenol, but not fumonisin B1, aflatoxin B1 or diesel exhaust particles disrupt integrity of the horse’s respiratory epithelium and predispose it for equine herpesvirus type 1 infection. The horse's respiratory tract daily encounters a plethora of respirable hazards including air pollutants, mycotoxins and airborne pathogens. To date, the precise effect of air pollution and mycotoxins on respiratory epithelial integrity and subsequent pathogen invasion in the horse has not been studied. Here, diesel exhaust particles (DEP) and three major mycotoxins (deoxynivalenol [DON], aflatoxin B1 [AFB1] and fumonisin B1 [FB1]) were applied to the apical surfaces of both ex vivo respiratory mucosal explants and in vitro primary equine respiratory epithelial cells (EREC) cultivated at the a...
Airborne particulate size and concentrations in five Thoroughbred training yards in Newmarket (UK). Despite their implication in the pathogenesis of lower airway inflammation, limited baseline data exists for airborne particulates in Thoroughbred racehorse stalls in the United Kingdom. This study documents airborne particulate size and concentrations in Newmarket training yards using a nephelometer (DustTrak DRX 8534, TSI). Each stall was sampled on a summer and winter day at three time points (morning, midday and evening). Minimum, mean and maximum/min ranges were calculated for the fraction of particulates with an aerodynamic diameter smaller than 2.5 μm (particulate matter (PM) 2.5) an...
Pollens destroy respiratory epithelial cell anchors and drive alphaherpesvirus infection. Pollens are well-known triggers of respiratory allergies and asthma. The pollen burden in today's ambient air is constantly increasing due to rising climate change and air pollution. How pollens interact with the respiratory mucosa remains largely unknown due to a lack of representative model systems. We here demonstrate how pollen proteases of Kentucky bluegrass, white birch and hazel selectively destroy integrity and anchorage of columnar respiratory epithelial cells, but not of basal cells, in both ex vivo respiratory mucosal explants and in vitro primary equine respiratory epithelial cells...
Fungi in respiratory samples of horses with inflammatory airway disease. Fungi contribute to the inflammatory response of lungs in horses with recurrent airway obstruction and in some forms of asthma in humans. The role of fungi in inflammatory airway disease (IAD) has not been assessed. Objective: Evaluate the prevalence of fungi in the respiratory samples of horses diagnosed with IAD, describe clinical signs associated with the presence of fungi in respiratory samples, and assess the risk factors associated with IAD and with the presence of fungi in the airways. Methods: Seven-hundred thirty-one active horses referred to a specialized ambulatory practice for sign...
Evaluation of a prototype dynamic laryngoplasty system in vitro with an equine vacuum airflow system. To evaluate a prototype dynamic laryngoplasty system (DLPS) in a static airflow model. Methods: Experimental. Methods: Ten equine larynges. Methods: The right arytenoid was fixed in abduction in all specimens. A left-sided laryngoplasty was performed with No. 2 Fiberwire and a FASTakII anchor. Each larynx was tested in a static airflow model. The system was adjusted to a flow rate of 55 L/s and prelaryngeal pressure of 12 mm Hg prior to testing in maximal arytenoid abduction. In phase 1, the left suture was loosened, shortened, and tested in 3-mm steps from 0 to 30 mm. In phase 2, the su...
Lower allergen levels in hypoallergenic Curly Horses? A comparison among breeds by measurements of horse allergens in hair and air samples. Exposure to horses can cause severe allergic reactions in sensitized individuals. The breed, American Bashkir Curly Horse is categorized as hypoallergenic, primarily due to reports of allergic patients experiencing fewer symptoms while handling this special breed. The possible reasons for this phenomenon could be lower allergen production and/or reduced allergen release into the air because of increased sebum content in their skin and hair compared to other breeds. Therefore, the aim of the current study was to compare different horse breeds in relation to allergen content in hair and airborne...
An observational study of environmental exposures, airway cytology, and performance in racing thoroughbreds. 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. Objective: Airway inflammation negatively affects performance and cytological phenotype varies with environmental exposure. Methods: 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 performe...
Microbiological quality of air in free-range and box-stall stable horse keeping systems. The aim of this study was to assess the microbiological quality of air in three horse riding centers differing in the horse keeping systems. The air samples were collected in one facility with free-range horse keeping system and two with box stalls of different sizes. The samples were collected over a period of 3 years (2015-2017), four times per year (spring, summer, autumn, winter) to assess the effect of seasonal changes. The prevalence of aerobic mesophilic bacteria, mold fungi, actinomycetes, Staphylococcus spp., and Escherichia coli was determined by the air collision method on Petri di...
Effect of ionization, bedding, and feeding on air quality in a horse stable. Organic dust is associated with Equine asthma. Ionization should reduce airborne dust levels. Objective: To determine the effect of ionization of air, type of bedding, and feed on the levels of airborne dust, endotoxin, and fungal colonies in horse stables. Methods: 24 healthy University-owned horses occupied the stables. Methods: A randomized controlled cross-over study. Four units with 6 stables were equipped with an ionization installation (25 VA, 5000 Volt Direct Current). Horses were kept either on wood shavings and fed haylage (2 units), or on straw and fed dry hay (2 units). Measurement...
The effect of stable bedding materials on dust levels, microbial air contamination and equine respiratory health. The choice of bedding material affects the quality of air in a stable and, consequently, the respiratory health of horses and humans. The risk of respiratory problems can be mitigated by improving the quality of air in the stable. The choice of bedding material is particularly important in cold climate conditions where horses are kept indoors throughout the year. This study examined the impact of three bedding materials: straw (S), peat with shavings (PS), and crushed wood pellets (CWP). The investigated factors were air contamination, including dust contamination and microbial (bacterial and ...