Environmental stressors encompass a range of external factors that can impact the health and well-being of horses. These stressors include temperature extremes, humidity, air quality, noise, and changes in habitat or management practices. Horses may exhibit physiological and behavioral responses to these stressors, which can affect their overall health, performance, and welfare. Research in this area focuses on understanding how environmental variables influence equine physiology and behavior, as well as identifying management strategies to mitigate negative effects. This page compiles peer-reviewed research studies and scholarly articles that explore the effects of environmental stressors on horses, examining their impact on health, performance, and welfare.
Gunson DE, Kowalczyk DF, Shoop CR, Ramberg CF.Several suspect causes of chronic zinc/cadmium toxicosis in horses near a zinc smelter were investigated following observations of lameness, swollen joints, and unthriftiness, particularly in foals. Two foals born and raised near the smelter were lame and had joint swellings that were attributable to severe generalized osteochondrosis. Zinc and cadmium concentrations were markedly increased in the pancreas, liver, and kidney. The serum of 1 foal, zinc and potassium concentrations were high, whereas calcium and magnesium concentrations were low. Marked nephrocalcinosis and osteoporosis were obs...
Barton MD, Hughes KL.A total of 189 isolates of Rhodococcus equi and related organisms and 16 marker strains representing the genera Rhodococcus and Corynebacterium were screened for 160 unit characters in a numerical taxonomic study. Analysis of the data indicated that R. equi forms a relatively homogeneous cluster distinctly separated from the recognized species of Rhodococcus and Corynebacterium (sensu stricto). Other members of the genus Rhodococcus are soil organisms and R. equi appears to fit into the genus on ecological as well as taxonomic grounds. It seems unlikely that R. equi could be a gastrointestinal...
Bjorland J, Norheim G.Much of the recent interest in cadmium has been inspired by concern about the increasing levels of this element in the environment. Exposure to low levels of cadmium may cause chronic effects. The intake of cadmium takes place mostly via foods. Therefore it is of interest to determine the cadmium levels in domestic animals in order to evaluate possible hazards both to animals and man.
Hryhorczuk DO, Withrow WA, Hesse CS, Beasley VR.The authors investigated an outbreaks of unusual illnesses in humans and horses residing within 1.3 km of a wire reclamation incinerator. The study included site visits; medical and veterinary examinations; analyses of furnace ash, fly ash, soil, and biologic samples for air residues. Tetrachlorodibenzo-p-dioxins (TCDDs) and tetrachlorodibenzofurans (TCDFs) were discovered in furnace ash, fly ash, soil, horse fat, and horse liver samples.
Crichlow EC, Yoshida K, Wallace K.Over a period of 4 months, in winter, the mean concentration of airborne particles in the ambient air of a riding stable was 0.41 mg/m3. This value was significantly higher than that found outdoors (0.04 mg/m3). During the day, levels of airborne particles were highest when stalls were cleaned and soiled bedding from the previous night replenished, and lowest when all stable activities had ceased. Fine particles, capable of entering the pulmonary alveoli, constituted 30 to 40 per cent of the total mass concentration of airborne particles.
Elinder CG, Jonsson L, Sternström T, Piscator M, Linnman L.The hardness of drinking water (i.e., the sum of calcium and magnesium concentrations) has been related to cadmium concentration in kidney cortex and to microscopic signs of arteriosclerosis and focal myocardial fibrosis in 50 Swedish horses slaughtered for meat production. A significant negative correlation was found between water hardness and cadmium concentrations in kidney cortex. This indicates that horses living in soft water areas are more inclined to accumulate cadmium from the general environment. Microscopic changes in the aorta and myocardium were approximately 2 times as frequent i...
McPherson EA, Lawson GH, Murphy JR, Nicholson JM, Breeze RG, Pirie HM.Breed, age, weight, type of work performed, seasonal onset, poor ventilation and exposure to moulds in the habitat were investigated in relation to the occurrence of chronic obstructive pulmonary disease (COPD). COPD was most commonly detected in showjumping and hacking horses. The older a horse, the more likely it was to become affected although most were 6 to 10 years of age. Of the horses in this sample of the population, which was not a random one, thoroughbred horses were affected least and ponies most often. The high incidence in ponies was related to their more frequent exposure to poor...
Carlson GP, Rumbaugh GE, Harrold D.Eight normal horses were held without access to food or water for 72 hours during a period of high environmental temperatures. During this period, the horses had an average weight loss of 51.6 kg (10.7% of body weight). Highly significant (P less than 0.001) decreases in extracellular fluid volume (18.6 L) and plasma volume (5 L) were observed during this period as compared with base-line values. Plasma protein, sodium, chloride, and osmolality progressively increased in response to the dehydration, whereas packed cell volume, plasma potassium, calcium, magnesium, and phosphate were not signif...
Foote RH.Several inherited conditions associated with testicular defects, abnormal spermatogenesis and morphologically abnormal sperm have been found. These usually are controlled by single gene pairs. A notable exception is testicular size, with heritability in young bulls ranging from .42 to .88. Testicular size directly affects sperm output potential. The major contributor to variation in semen quality is the environment. Environmental effects may be temporary or permanent. Permanent effects occurring during prenatal and prepubertal periods and temporary or permanent factors acting after spermatogen...
Woollam DH.The history of teratology is reviewed. Methods available for causing malformations in mammals by subtle changes in the environment during pregnancy are discussed. A table is provided in which the commoner teratogens are listed. Methods are described by means of which the activity of some common teratogens may be opposed. The occurrence at Battle Creek, Michigan, USA, of a chemical agent dangerous to health, life and development of all mammals is described. This gives an indication that injury and death to all mammals, as in the Sevaso disaster, including teratogenesis may be expected to be a f...
Johnson HD, Vanjonack WJ.Recent data on various environmental stressors and blood hormone patterns are presented for lactating cattle. Known stressor effects of such factors as environmental temperature, air pollution, and noise on the plasma thyroxine, growth hormone, cortisol, prolactin, progesterone, luteinzing hormone, epinephrine, and norepinephrine of lactating cattle are discussed. Information on stressor effects is lacking on glucagon, insulin, vasopressin, calcitonin, oxytocin, thyrotrophic hormone, follicle stimulating hormone, melatonin, parathyroid hormone, and estrogens in the lactating cow. The importanc...
Science (New York, N.Y.)May 26, 1975
Volume 188, Issue 4189 738-740 doi: 10.1126/science.1168366
Carter CD, Kimbrough RD, Liddle JA, Cline RE, Zack MM, Barthel WF, Koehler RE, Phillips PE.Tetrachlorodibenzodioxin was identified as the apparent cause of an outbreak of poisoning in humans, horses, and other animals. Exposure was related to the spraying of contaminated waste oil on riding arenas for dust control. The contamination resulted from improper disposal of a toxic industrial waste. The pathologic effects and chemical identification of tetrachlorodibenzodioxin are described.
Marsella R.Information on skin barrier in horses is limited. A study on the epidermal ultrastructure of normal and allergic horses documented disorganized amorphous intercellular lipids in the stratum corneum of allergic samples. These findings are similar to atopic canine and human skin. Currently, there is no published study comparing skin barrier function parameters between normal and allergic horses; thus, the functional implications of the ultrastructural changes are unknown. In normal horses, body location, gender, breed, and ambient conditions affect skin barrier parameters, such as Transepidermal...
Pipereau K, Trably E, Santa-Catalina G, García-Bernet D, Carrere H.This study focuses on thermal and non-thermal effects of microwave pretreatment on horse dung as indigenous inoculum before xylose and wheat straw fermentation, emphasizing metabolite production and microbial community changes. Two horse dung microwave pretreatments (MW40°C and MW95°C) were compared with a conventional thermal pretreatment (Th95°C) and an unpretreated condition (Ctrl). Microwave heating pretreatment (MW95°C) leads to similar production as a conventional thermal pretreatment (Th95°C) for xylose and wheat straw fermentation while MW40°C treatment was similar to the control...
Kaštovská E, Mastný J, Choma M, Čapek P, Jirků M, Bitomský M, Konvička M.Based on a growing understanding of the role of wild megafauna in the functioning of natural ecosystems, trophic rewilding by large herbivores is increasingly used as a nature-based solution to mitigate biodiversity loss and climate change in Europe and beyond. Despite the growing interest in implementing nature-based approaches to restore key non-productive ecosystem services, there is relatively little data available to assess the benefits and risks of rewilding projects. We therefore investigated the effects of year-round grazing by large ungulates on plant biomass characteristics and their...
Marchi S, Amodeo D, Peccetti B, De Palma I, Messina G, Montomoli E, Trombetta CM.Influenza D virus (IDV) is a novel influenza virus, first isolated from swine with influenza-like symptoms in the USA in 2011. To date, IDV circulation has been reported in various animal species such as cattle, pigs, horses with the ability to expand its range of hosts. UV radiation has been widely used for the disinfection of various sources such as water, air, and surfaces, especially in places at greater risk of contamination by viruses and bacteria, such as hospitals and health facilities. The aim of this study was to evaluate the potential virucidal effect of a violet-blue light against ...
The potential of effective microorganisms in composting animal manure might be significant. This work aimed at isolating promising microbial strains for composting cattle and horse manure. A total of forty-five isolates have been isolated from soils of Northern Kazakhstan as well as cattle and horse manure. These microorganisms were extensively studied for their cellulose-degrading capacity, non-pathogenicity, protease, nitrogenase and catalase activities, as well as their growth stimulation, antagonistic ability, and growth rate. As a result, 21 potent strains were selected and genotyped for ...
Zhang X, Abdusuli N.The horse industry constitutes a vital economic sector in Xinjiang, China. This study quantitatively assesses the sector's sustainable development through eco-efficiency analysis across northern Xinjiang counties from 2001 to 2021. The research employs four analytical methods: the S-SBM model for efficiency measurement, kernel density estimation for distribution analysis, Moran's index for spatial autocorrelation examination, and convergence tests for long-term trend assessment. Results demonstrate a consistent decline in eco-efficiency, decreasing from 0.821 in 2001 to 0.444 in 2021, with an ...
Pipereau K, Trably E, Santa-Catalina G, García-Bernet D, Carrere H.Horse manure is a lignocellulosic biomass found in significant quantities with a vast indigenous flora, not yet fully valorized apart from anaerobic digestion. Its use in the fermentation process can lead to the production of higher-value metabolites. This study investigates three inoculation strategies coupled with five pretreatment conditions for horse manure fermentation. Two microwave pretreatments (200W and 1000W) were compared with a conventional thermal pretreatment, a thermo-acid pretreatment, and an unpretreated condition. The sole horse manure indigenous microorganisms were used in f...
Gobbo E, Maccario C, Zupan Šemrov M, Bovo M, Atallah E, Minero M, Dalla Costa E.Methods to assess the positive behavior of horses in relation to their environment can be used to provide information to enhance animal welfare. One of the most important experiences that can be observed in mammals is sleep, a universal behavior relevant for the welfare of all species. To achieve paradoxical sleep, horses must lie down in lateral recumbency for a sufficient time, but they only do so when feeling safe and comfortable. Recently, technological tools like accelerometers have opened the possibility of non-invasive continuous monitoring of lying behavior, thus implementing the way w...
Sanigavatee K, Wonghanchao T, Poochipakorn C, Pongnarudech P, Suchairat T, Jitsopin S, Wanichayanon B, Sripiboon S, Chanda M.Long-distance road transport is known to be stressful for horses, with most research conducted in temperate climates. This study investigated horses' stress responses during long-distance transport before and after a jumping competition in a tropical environment. Ten healthy horses (aged 7.9 ± 1.9 years) were studied. Blood cortisol concentrations, haematology, and heart rate variability (HRV) were monitored during outbound (OTJ) and inbound journeys (INJ). Cortisol concentrations increased five minutes after unloading and remained elevated for up to 180 minutes in the OTJ (P < 0.05-0.001)...
Mutillod C, Buisson E, Tatin L, Mahy G, Dufrêne M, Morvan N, Mesléard F, Dutoit T.The urgency of restoring ecosystems over vast areas has placed rewilding using wild herbivores at the forefront. However, few scientific studies address its effects on biodiversity and ecosystem functioning compared to more traditional conservation interventions with domestic herbivores. Equus ferus przewalskii horses introduced 30 years ago in the National Park of Cévennes, France - as a step of a conservation program of the species for its reintroduction in Mongolia - now occur as a semi-wild horse population, socially natural (i.e., management is based on natural selection). This introduct...
Andreas C.The virus that causes African horsesickness does not affect any indigenous species, but produces high mortality among horses, a species introduced by the Dutch East India Company in 1653. While the insect-borne disease did not occur in the immediate vicinity of the Cape Peninsula, horsesickness could have constituted an endemic disease barrier to the horse-based expansion of the colonial sphere into the hinterland, where it was seasonally prevalent. That it did so to only a limited extent is due to a substantial alteration of the ecology of the disease that largely resulted from inadvertent si...
Santana ML, Bignardi AB, Faria RAS, Silva JAIV.Thermal load is a major welfare and performance concern for athletic horses, as physical exertion increases internal heat production. Although several phenotypic strategies have been developed to mitigate its effects, the genetic basis of thermal tolerance in horses remains largely unexplored. This study aimed to (1) evaluate the influence of thermal indices on the racing performance of Brazilian Quarter Horses, and (2) investigate the genetic basis of thermal tolerance through the estimation of genetic parameters across temperature gradients. We analyzed 21,857 racing-time (RT) records from 5...
Takahashi K, Shirai T, Mukai K, Ebisuda Y, Sugiyama F, Yoshida T, Kitaoka Y.While exercise performance deteriorates in hot environments, heat stress may contribute to exercise-induced adaptations in skeletal muscle. In this study, we assessed transcriptional profiles of equine skeletal muscle following 3 min of high-intensity exercise (at the speed eliciting their maximal oxygen uptake) in cool [wet bulb globe temperature (WBGT) 15°C] or hot (WBGT 30°C) conditions. Differential gene expression was identified using DESeq2 (false discovery rate cutoff: 0.05, minimal fold change: 1.5). At 4 h after exercise, RNA-seq identified 176 and 156 genes that were differentially...
Sosa-Portugal S, Dale L, Devaney J, Sharp A, Malalana F, Timofte D.The "ESKAPE" bacteria include a group of organisms known for their multidrug resistance and potential association with nosocomial infections in human and veterinary hospitals. Objective: This study aimed to evaluate the effectiveness of steam cleaning in reducing the number of ESKAPE organisms on environmental surfaces from the stables of an equine veterinary referral hospital. Methods: Environmental sampling was performed at two timepoints (pre- and post-steam cleaning) on smooth metallic doors and rough rubber stable walls. Microbiological culture targeted ESKAPE organisms and Escherichia co...
Dos Santos Gomes V, Dos Santos Marques JV, da Silva GN, Marmett B, Dallegrave E.The inhalation of pollutants from fossil fuel combustion increases oxidative stress and may cause genotoxic damage, a risk heightened during physical exercise due to increased respiratory rates. This concern extends to equines engaged in intense activities like show jumping. Antioxidant supplementation with vitamin E and selenium may mitigate oxidative stress induced by exercise in polluted environments. This study evaluated the effects of oral supplementation on show jumping horses subjected to physical exertion in urban (n = 10) and peri-urban (n = 10) areas with varying pollution le...
Mukhanbetkaliyev Y, Yessembekova G, Mukhanbetkaliyeva A, Akmambayeva B, Kadyrov A, Uskenov R, Bostanova S, Ashirbek A, Korennoy F, Abdrakhmanov S.Equine herpesvirus 1 (EHV-1) is one of the most dangerous viral diseases affecting ungulates, and is characterized by a wide range of clinical manifestations in horses, including rhinopneumonia, abortion, neonatal death, and myeloencephalopathy. It is well known for causing mass abortions in mares and respiratory diseases in young animals. Once introduced into a horse breeding farm of any type, EHV-1 tends to establish as a persistent infection. The disease is reported on nearly all continents and causes substantial annual economic losses to horse breeding operations. In Kazakhstan, 34 EHV-1 o...
Poochipakorn C, Sanigavatee K, Leelehapongsathon K, Wonghanchao T, Chanda M.The impact of climate conditions and stable design on horses housed in individual stalls plays a significant role in their well-being, especially in tropical climates. Limited information exists regarding their conditions during the monsoon season. Objective: This study focused on the stable microclimate and autonomic regulation of horses kept in different stable architectures during the monsoon in a tropical setting. Methods: Twenty-two horses were assigned to one of three stable designs, each offering unique microclimates, including relative humidity, air temperature, and various levels of n...
Čebulj-Kadunc N, Frangež R, Kruljc P.The aim of the study was to determine the fluctuations of selected physiological parameters in young Lipizzan stallions ( = 10) during the initial phase of their training as indicators of adaptation to a graded exercise load and stress exposure. For this purpose, four exercise tests (ExT) with lunging were carried out over a period of one year. Physiological parameters (gait speed, heart and respiratory rate (HR and RR), rectal and body surface temperature (RT and BST), and cortisol and lactate concentration (CORT and LAC)) were measured before and after training. In all ExT, gait speeds incre...
Louro LF, Sinclair C, Hargreaves L, Coumbe K, Hajeeh Ali M, Percan V, Bacon B, Kukaswadia A, Mair T.The healthcare sector contributes significantly to global greenhouse gas (GHG) emissions, with anaesthetic gases being a notable contributor. Implementing sustainable practices in equine anaesthesia, such as low-flow anaesthesia, offers potential benefits. Objective: To audit oxygen and isoflurane usage in five equine hospitals, their associated GHG emissions, and the impact of anaesthesia training on mitigating these emissions. Methods: Multi-centre clinical audit. Methods: This audit covered two periods: study period one (1 June-30 September 2022) and study period two (1 June-30 September 20...
Brauns M, Ali A, Berger J, McLean A.Small stalls and regulated feedings restrict horses' natural foraging and locomotion, increasing risks to welfare. Environmental enrichment may promote more naturalistic behavioral time budgets, yet little is known about how enrichment type or timing affects physiology and behavior. This study examined nine stabled Quarter Horses provided with hay feeders, activity balls, or mirrors across randomized trials. Each trial included 30 min observations, four times per day, with enrichment removed between sessions and 5-day washouts between trials. Nightwatch Smart Halters™ recorded heart and resp...
Hanousek K, O'Hara V, Riddell DO, Piercy RJ.In Thoroughbred horses, a highly prevalent short interspersed nuclear element (SINE) mutation in the myostatin gene (MSTN) promoter influences circulating myostatin concentration and is associated with muscle morphology, fracture risk and optimal race distance. Our prior data reveal that within horses there is substantial variation in serum myostatin concentration, particularly in MSTN heterozygotes and wild type horses but it was unclear whether such variation relates to within-horse differences or to environmental or temporal effects. Here we report the intra-horse consistency of circulating...
Pereira GF, Blimbliem MCH, Machado ALPR, Abdala JBR, Nogueira GM, Toma HS, de Carvalho TF, Delfiol DJZ.Arsenic poisoning in horses is rarely reported in the literature. However, arsenic compounds can be present in rodenticides, pesticides, and herbicides, representing a potential source of accidental exposure for horses. Objective: To describe the epidemiological, clinical, and laboratory findings from a herd of 31 horses exposed to pasture treated with an overdose of sodium hydrogen methylarsonate, and to compare results in a group of horses exposed to the recommended dosage of the same product. Methods: Observational field study. Methods: Thirty-one horses were evaluated after grazing on a pa...
Ake AS, Akinniyi OO.Clinical assessment of parameters that give indications of the health status and fitness of horses are very important in equine practice. The study aimed to compare the resting body temperatures at different anatomical sites and resting pulse rates of athletic and non-athletic horses. Eighteen horses were used for the study, comprising ten athletic and eight non-athletic horses. Measurements of environmental parameters, rectal temperature (RT), body surface temperature (BST) and pulse rate were recorded between 9 and 11 am twice with one week interval at the Ibadan Polo Club, Eleyele, Ibadan, ...
Wickizer LF, Burk SV, Lehman JS.Red maple toxicosis arises when horses consume wilted maple leaves, resulting in methemoglobinemia and hemolytic anemia due to oxidative damage to erythrocytes. Objective: The objective of this study was to determine how maple species (red versus Freeman maple) and horse characteristics, management, and barn site contributed to in vitro methemoglobin production and hemolysis. Methods: Horse information was obtained through an owner questionnaire. Extracts from red and Freeman maple leaves were separately incubated with washed erythrocytes from each horse (n=120). The in vitro percentage methem...
Rinnovati R, Meistro F, Ralletti MV, D'Angelo P, Spadari A, Zingariello E, Pollera C, Stancampiano L.In horses, surgical site infections (SSIs) are multifactorial complications influenced by patient-related, procedural, and environmental factors. While perioperative contamination has been extensively studied in the operating theater, the anesthetic induction and recovery environment has received limited attention. The aim of this study was to characterize bacterial contamination within an equine anesthetic induction and recovery stall and to evaluate its spatial and temporal distribution. Environmental samples were collected from four predefined locations within the stall at three time points...
Tsytlishvili K.The pursuit of sustainable livestock farming and environmentally responsible agricultural practices has spurred the development of innovative and affordable wastewater treatment technologies. This study investigates new biological treatment approaches that integrate the complementary processes of filtration, biosorption, and biodegradation to enhance eco-friendly wastewater management. A novel treatment concept was developed, representing a modern modification of the biosorption method that combines the oxidation of organic pollutants with ammonium reduction by an immobilized biocenosis, achie...
Environmental contamination with heavy metals, resulting from industrialization, urbanization, and agricultural intensification, poses serious ecological and health risks. Horses, due to their grazing behavior and close association with human environments, serve as reliable sentinel species for assessing environmental pollution. This study aimed to evaluate the bioaccumulation of heavy metals and trace elements in different biological matrices of horses-blood, hair, hooves, and synovial fluid-and to investigate their relationship with hematological biomarkers as indicators of physiological str...
West Nile Virus (WNV) is a mosquito-borne zoonosis with recurrent equine and human cases in Romania. Horses, although dead-end hosts, act as sentinels for local viral circulation. Farm-level risk conditions remain under-characterized. This pilot, exploratory cross-sectional study assessed 42 equine facilities in western Romania (2024). A standardized 10-item checklist was applied and a Composite Environmental Risk Score (CERS) (0-10, unweighted) was computed per facility. Spatial analysis in QGIS included distances to nearby water bodies. No serological or entomological data were collected; th...
Dindo S, Tovar-Pascual L, Baldassarro VA, Bucci D, Mislei B, Spinaci M, Ortiz-Rodriguez JM.Nanoplastics (NP) accumulation in biological tissues and their adverse effects on fertility through inflammatory and oxidative stress responses have recently been described as consequences of global plastic pollution. However, little is known about the impact of NP on gametes. This study aimed to assess the internalization of NP and their effects on mature equine spermatozoa. Frozen-thawed ejaculates from five stallions were divided into untreated control (CTR) and samples supplemented with different concentrations (10, 50, 100 and 200 μg/mL) of 30 nm polystyrene NP. At baseline (T0), and a...
