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.
Tarazona AM, Ceballos MC, Broom DM.Excessive human population growth, uncontrolled use of natural resources, including deforestation, mining, wasteful systems, biodiversity reduction by agriculture, and damaging climate change affect the existence of all animals, including humans. This discussion is now urgent and people are rethinking their links with the animals we use for clothing, food, work, companionship, entertainment, and research. The concepts of one health, one welfare, and one biology are discussed as a background to driving global change. Nothing should be exploited without considering the ethics of the action and t...
López-Sánchez A, Perea R, Roig S, Isselstein J, Schmitz A.Traditional orchard meadows are among the most valuable cultural and agricultural systems for nature conservation in Europe. They comprise scattered fruit trees over a highly diverse herbaceous layer and provide a wide range of ecosystem services. However, they are strongly endangered due to farmland intensification and abandonment. Livestock grazing is known to promote grassland diversity but it may also cause tree damage through debarking. In this study, we evaluated the effect of different grazers (cattle, horse and sheep) on fruit trees in 42 traditional orchards of the Rhenish uplands (Ge...
Fowden AL, Giussani DA, Forhead AJ.In many species, the pattern of growth and physiological development in utero has an important role in determining not only neonatal viability but also adult phenotype and disease susceptibility. Changes in fetal development induced by a range of environmental factors including maternal nutrition, disease, placental insufficiency and social stresses have all been shown to induce adult cardiovascular and metabolic dysfunction that often lead to ill health in later life. Compared to other precocious animals, much less is known about the physiological development of the fetal horse or the longer-...
Hannant D.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. […]
Rodrigues JA, Gonçalves AR, Antunes L, Bettencourt EV, Gama LT.Breeding and parturition records collected over a period of 35 years in the Alter Real stud of Lusitano horses were used to calculate gestation length (GL). The 1027 gestations by 209 mares mated to 60 stallions had a mean GL of 338.1 ± 9.26 days. The mixed model analysis of variance indicated that the sex of the foal and inbreeding of the dam and foal had no significant effect on GL (P > .05). On the other hand, GL increased linearly with mare age, with an estimated regression coefficient of 0.155 ± 0.069 days/year (P < .05). Year and conception month affected GL (P < .05), with longer g...
Fazio F, Cicero N, Piccione G, Giannetto C, Licata P.Mercury (Hg) exists in various chemical forms, and it is different to health effects. The most toxic effects occur in the central nervous system during fetal development with irreversible alterations of the nerve cells of the cerebral cortex and, it is essential to monitor the tissue residues of Hg to protect the animal's health. The present investigation was carried out during May 2019 in 20 horses located in equine sport center near the area of Milazzo, Messina, that is a part of Sicilian territory heavily polluted by many toxic substances. The purpose of this study was to determine the conc...
Denham J.Telomeres are genetically conserved nucleoprotein complexes located at the ends of chromosomes that preserve genomic stability. In large mammals, somatic cell telomeres shorten with age, owing to the end replication problem and lack of telomere-lengthening events (e.g. telomerase and ALT activity). Therefore, telomere length reflects cellular replicative reserve and mitotic potential. Environmental insults can accelerate telomere attrition in response to cell division and DNA damage. As such, telomere shortening is considered one of the major hallmarks of ageing. Much effort has been dedicate...
Sheats MK, Davis KU, Poole JA.Farmers are routinely exposed to organic dusts and aeroallergens that can have adverse respiratory health effects including asthma. Horses are farm-reared large animals with similar exposures and can develop equine asthma syndrome (EAS). This review aims to compare the etiology, pathophysiology, and immunology of asthma in horses compared to farmers and highlights the horse as a potential translational animal model for organic dust-induced asthma in humans. Severe EAS shares many clinical and pathological features with various phenotypes of human asthma including allergic, non-allergic, late o...
Forsyth J, Halliwell RE, Harrand R.Identification of environmental allergens in horses with allergic disease facilitates allergen avoidance and targeted immunotherapy. Objective: To evaluate allergenic co-reactivity between 44 environmental allergens. Methods: Horses with suspected allergic disease (n = 344) whose sera were submitted for environmental allergen testing. Methods: Allergen-specific IgE serological assays were performed using 44 allergens divided into six taxonomically related groups: house dust/storage mites, moulds, insects, grass, tree and weed pollens. Using pairwise comparisons, odds ratios (ORs) were calcul...
Li Y, Zhang K, Liu Y, Li K, Hu D, Wronski T.Large and complex intestinal microbiota communities in hosts have profound effects on digestion and metabolism. To better understand the community structure of intestinal microbiota in Przewalski's horse () under different feeding regimes, we compared bacterial diversity and composition between captive and reintroduced Przewalski's horses, using high-throughput 16S-rRNA gene sequencing for identification. Reintroduced Przewalski's horses were sampled in two Chinese nature reserves, i.e., Dunhuang Xihu Nature Reserve (DXNR; = 8) in Gansu Province and Kalamaili Nature Reserve (KNR; = 12) in Xi...
Ringmark S, Skarin A, Jansson A.Horse grazing may benefit biodiversity, but the impact of year-round grazing on nutrient dynamics has not been evaluated previously. This study compared pasture quality in a forest-grassland landscape grazed year-round by horses with that in exclosed mown areas. Twelve Gotlandsruss stallions were kept without supplementary feeding in three enclosures (~0.35 horse/ha) outside Uppsala, Sweden, from May 2014 to September 2016. Each enclosure contained three mown exclosures, where grass sward samples were collected monthly and analyzed for chemical composition and vegetation density. Fecal grab sa...
Nomura M, Shiose T, Ishikawa Y, Mizobe F, Sakai S, Kusano K.Despite growing recognition of post-race exertional heat illness (EHI) in the horse racing industry, reports on its prevalence are limited. The purpose of this study was to investigate the prevalence of post-race EHI and climate conditions at racecourses in Japan. The overall prevalence of EHI from 1999 to 2018 was 0.04% (387 cases for 975,247 starters) in races operated by the Japan Racing Association (JRA). The yearly prevalence has been increasing, exceeding 0.07% in the last four years of the studied period. The overall prevalence in summer (May-September) was 0.086% (352 cases for 409,908...
Claußen G, Grau D, Hessel EF.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 ...
GarcÃa EDA, Khusro A, Pacheco EBF, Adegbeye MJ, Barbabosa-Pliego A, Lagunas BC, Salas JMC, Mateos RG, Aarti C, Elghandour MMMY.The present context was designed to investigate the efficacy of devil fish (DF; Plecostomus sp.) silage and Staphylococcus saprophyticus on fermentation characteristics as well as greenhouse gases production mitigation attributes in horses. Four levels of ensiled DF at 0 (control DF0), 6 (DF6), 12 (DF12), and 18 (DF18) % were added into the diet. Moreover, three doses of S. saprophyticus (0, 1, and 3 mL/g dry matter [DM]) were used for in vitro fecal fermentation. The use of ensiled DF resulted in increased (P < .0001) pH during fermentation. The asymptotic gas production was the highest (P...
Catalano DN, Heins BJ, Missaghi S, Hathaway MR, Martinson KL.Goldfish (Carassius auratus) have been reported as a method to keep water tanks clean; however, little information exists on this approach. The objectives were to evaluate the efficacy of goldfish on maintaining water quality in tanks and to evaluate the frequency that this method is used. The first objective was completed during June through October 2017 in St. Paul, MN, using plastic and metal 379Â L stock tanks, each with and without goldfish in a drylot that housed six adult horses. The stocking rate was 5 goldfish per tank. Daily readings of total dissolved solids (TDS) and water turbidit...
Stojiljkovic N, Leroux F, Bubanj S, Popot MA, Paris A, Tabet JC, Junot C.There is an urgent need to implement holistic and untargeted doping control protocols with improved discriminatory power, compared to conventional methods that only target doping agents. Metabolomics, which aims to characterize all metabolites present in biological matrices, could fulfill this need. In this context, the aim of this study was to evaluate the impact of environmental factors on the ability to obtain a metabolic signature of stanozolol administration in horse doping situation. Urine samples from 16 horses breeded in two different places were collected over a one-year period, befor...
Davison JA, Wylie CE, McGladdery CE, Fettes C, Haggett EF, Ramzan PHL.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...
Gold S, Regan CE, McLoughlin PD, Gilleard JS, Wilson AJ, Poissant J.Variability in host resistance or tolerance to parasites is nearly ubiquitous, and is of key significance in understanding the evolutionary processes shaping host-parasite interactions. While ample research has been conducted on the genetics of parasite burden in livestock, relatively little has been done in free-living populations. Here, we investigate the sources of (co)variation in strongyle nematode faecal egg count (FEC) and body condition in Sable Island horses, a feral population in which parasite burden has previously been shown to negatively correlate with body condition. We used the ...
Huber L, Giguère S, Cohen ND, Slovis NM, Berghaus L, Greiter M, Hart KA.Rhodococcus equi causes severe pneumonia in foals and is most often recognized in people as an opportunistic pathogen. Longitudinal studies examining antimicrobial-resistant R. equi from environmental samples are lacking. We hypothesized that antimicrobial-resistant R. equi would be detectable in the ground (pasture soil or stall bedding) and air at breeding farms with previous documentation of foals infected with resistant isolates, and that concentrations of resistant isolates would increase over time during the foaling season. In this prospective cohort study, ground and air samples were co...
Adegbeye MJ, Elghandour MMMY, Barbabosa-Pliego A, Monroy JC, Mellado M, Ravi Kanth Reddy P, Salem AZM.Several concerns exist regarding horse rearing such as environmental pollution, antibiotics resistance, digestive disorders, mycotoxins contamination of animal feed, gut health management, and improvement of feed efficiency. Nanoparticles have the potential to address these issues and thus could be used as feed additive. Citrate reduces and stabilizes gold nanoparticles, alongside biosynthesized silver nanoparticles have the potential to prolong and improve digestive enzyme activity, which would enhance starch digestibility in the stomach. Zinc oxide and selenium nanoparticles could be used to...
Van Cleemput J, Poelaert KCK, Laval K, Impens F, Van den Broeck W, Gevaert K, Nauwynck HJ.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...
Melchert M, Aurich C, Aurich J, Gautier C, Nagel C.Mares usually give birth when they perceive their environment as safe and therefore disturbance at foaling may inhibit labor. In this study, foaling mares were transferred to an unfamiliar environment at rupture of the allantochorion (stress, n = 6) or were left undisturbed (control, n = 5). The progress of foaling, heart rate, heart rate variability (HRV) and plasma catecholamine, oxytocin and cortisol concentration were determined. In stressed mares, time from rupture of the allantochorion to appearance of the fetal feet (5.3 ± 1.1 vs. 1.6 ± 0.4 min) and total length of f...
Yamada K, Araki M, Tokushige H, Fujiki R, Sakai S, Tateno O, Mashita S, Kusano K.Equine scintigraphy has been legally permitted in Japan since 2009; however, it has not yet been a routine modality for horses. One reason is the legal regulations concerning the disposal of contaminated bedding. However, overseas, the bedding after scintigraphy can be disposed following radioactivity decay, but this is not allowed in Japan. Therefore, beddings are required to stored permanently in a controlled area, implying that large amounts of beddings such as straw would be kept untreated, which is quite unpractical. This may cause a hospital owner to hesitate to construct an equine scint...
Durward-Akhurst SA, Schultz NE, Norton EM, Rendahl AK, Besselink H, Behnisch PA, Brouwer A, Geor RJ, Mickelson JR, McCue ME.Equine Metabolic Syndrome (EMS) is characterized by abnormalities in insulin regulation, increased adiposity and laminitis, and has several similarities to human metabolic syndrome. A large amount of environmental variability in the EMS phenotype is not explained by commonly measured factors (diet, exercise, and season), suggesting that other environmental factors play a role in EMS development. Endocrine disrupting chemicals (EDCs) are associated with metabolic syndrome and other endocrine abnormalities in humans. This led us to hypothesize that EDCs are detectable in horse plasma and play a ...
Elghandour MMMY, Adegbeye MJ, Barbabosa-Pilego A, Perez NR, Hernández SR, Zaragoza-Bastida A, Salem AZM.Greenhouses gas emission mitigation is a very important aspect of earth sustainability with greenhouse gasses reduction, a focus of agricultural and petrochemical industries. Methane is produced in nonruminant herbivores such as horses because they undergo hindgut fermentation. Although equine produce less methane than ruminant, increasing population of horses might increase their contribution to the present 1.2 to 1.7 Tg, estimate. Diet, feeding frequency, season, genome, and protozoa population influence methane production equine. In population, Methanomicrobiales, Methanosarcinales, Methan...
Huber L, Giguère S, Berghaus LJ, Hanafi A, Ryan C.Rhodococcus equi, a soil saprophyte, is a common cause of pneumonia in foals and a frequent opportunistic pathogen in immunosuppressed people. Because it is widespread in the environment, R. equi can be detected in the feces of most horses. However, the exact timing and rate of shedding relative to infection is unknown. The objectives of this study were to quantify shedding of R. equi in mares and foals after experimental infection of foals with 2 different inocula and to determine the effect of composting on concentrations of R. equi in contaminated bedding. Foals were infected intratracheall...
Rua MAS, Quirino CR, Rodrigues ACC, Christo MM, Barreto MAP.The objective of this study was to evaluate the environmental effects on embryo recovery rate and pregnancy rate of Mangalarga Marchador mares. The reproductive characteristics of donor and recipient mares were evaluated during five years in Brazilian tropical environment. The mares were used throughout the year and seasons were classified as: October to April (breeding season - BS); May (autumn transition out of the breeding season - ATBS); June to August (non-breeding season - nBS); and September (vernal transition into the breeding season - VTBS). Daily temperature rainfall and hours of day...
Du G, Feng W, Cai H, Ma Z, Liu X, Yuan C, Shi J, Zhang B.Composting has been a rational method to dispose of horse or wildlife animal manures, especially in the developed cities with horse clubs and wildlife parks. However, few studies have focused on the mechanism and improvement methods for composting the horse or wildlife animal manures. In this study, we investigated the effect of exogenous compound enzymes on thermophilic composting, which could potentially support the management of horse and wildlife animal manures. With the presence of exogenous enzymes, the duration of high temperature (> 60 °C) was significantly prolonged (p <â€...
Goehring LS, van Maanen C, Sloet van Oldruitenborgh-Oosterbaan MM.The presence of toxins or infectious agents combined with environmental factors in combination with a susceptible host can be the cause for neurological disease in groups of horses. During a 5 year observational period outbreaks of neurological diseases among horses were evaluated. Causes of occurring neurological diseases were equine botulism, lolitrem intoxications, equine herpesvirus type 1-associated myelo(encephalo)pathy, and encephalitis caused by (disseminated) Streptococcus equi subspecies equi infection. This article focuses on the first three syndromes because of their predominant in...
Weideman H, Schoeman SJ, Jordaan GF, Kidd M.This study investigated if environmental factors had an effect on the incidence of epistaxis related to exercise-induced pulmonary haemorrhage (EIPH) among racehorses in southern Africa. Data covering the period 1986-2001 and involving 778 532 race runs were analysed. This included the following information: date of race, age, sex, name of breeder, trainer, distance, jockey, state of going, weight carried, racing centre and altitude. Veterinarians employed by the Jockey Club suspended officially entered horses that presented with epistaxis (frank bleeding from the nostrils) after racing. On-co...
Nanda S, Dalai AK, Gökalp I, Kozinski JA.The organic wastes such as lignocellulosic biomass, municipal solid waste, sewage sludge and livestock manure have attracted attention as alternative sources of energy. Cattle manure, a waste generated in surplus amounts from the feedlot, has always been a chief environmental concern. This study is focused on identifying the candidacy of horse manure as a next generation feedstock for biofuel production through supercritical water gasification. The horse manure was gasified in supercritical water to examine the effects of temperature (400-600°C), biomass-to-water ratio (1:5 and 1:10) and reac...
Stachurska A, Robovský J, Bocian K, Janczarek I.Changes in the coat cover are important for mammalian thermoregulation. This is especially true where variable environmental conditions exist throughout the seasons. Coat cover shedding is the replacement of old coat hair with new hair. The process differs in various equids. The aim of the study was to examine the changes in the coat of primitive Polish Konik horses living on a reserve in southeast Poland (50.6319° N). The reserve is located in a temperate climate. The mean temperature is below 0°C in winter (December 8 to March 9) and over 15°C in summer (June 8 to September 8). Five adult...
Marsella R.Allergies are common in horses. It is important to identify and correct as many factors as possible to control pruritus and make the patient comfortable. Culicoides hypersensitivity is a common component in allergic horses. The main treatment continues to be rigorous fly control and avoidance of insect bites. Environmental allergies are best addressed by early identification of the offending allergens and formulation of allergen-specific immunotherapy to decrease the need for rescue medications. Food allergy is best managed with food avoidance. Urticaria is one of the manifestations of allergi...
Nomura M, Shiose T, Ishikawa Y, Mizobe F, Sakai S, Kusano K.Despite growing recognition of post-race exertional heat illness (EHI) in the horse racing industry, reports on its prevalence are limited. The purpose of this study was to investigate the prevalence of post-race EHI and climate conditions at racecourses in Japan. The overall prevalence of EHI from 1999 to 2018 was 0.04% (387 cases for 975,247 starters) in races operated by the Japan Racing Association (JRA). The yearly prevalence has been increasing, exceeding 0.07% in the last four years of the studied period. The overall prevalence in summer (May-September) was 0.086% (352 cases for 409,908...
Thomson JR, McPherson EA.The therapy of equine chronic obstructive pulmonary disease (COPD) essentially entails minimising the horse's exposure to the aetiological antigens which are predominantly thermophilic actinomycetes and moulds occurring in hay and straw. This can be achieved, for example, by keeping affected horses permanently out of doors, or when stabled, using shredded paper, wood shavings or peat moss as bedding and feeding a complete cubed diet. There should be no supplementary hay feeding apart from dust-free vacuum-packed hay. Applying such measures generally allows horses to become asymptomatic in seve...
Bernátková A, Oyunsaikhan G, Šimek J, Komárková M, Bobek M, Ceacero F.Reintroduction is a common technique for re-establishing threatened species. However, the adaptation to novel habitats with distinct conditions poses a risk of failure. Weather conditions affect the behaviour of animals, and thus, their adaptation to new conditions and survival. Reintroduced Przewalski's horses living in Mongolia's continental arid climate with extreme temperature and precipitation variability, serve as an ideal model species for studying the behavioural response of selected groups to these harsh conditions. Methods: The research was conducted in The Great Gobi B Strictly Prot...
Wyse CA, Skeldon K, Hotchkiss JW, Gibson G, Yam PS, Christley RM, Preston T, Cumming DR, Padgett M, Cooper JC, Love S.The aim of this study was to assess the effects of changes to the stable environment on exhaled markers of respiratory inflammation in six horses with clinical histories of recurrent airway obstruction. The horses were maintained for two weeks under conventional stable management (straw bedding and hay) and for two weeks on a reduced-dust regimen (paper bedding and ensiled grass), in a crossover study design. Exhaled ethane and carbon monoxide (CO) and exhaled breath condensate hydrogen peroxide (H(2)O(2)) were measured every three days under each regimen. The presence of clinical signs of air...
Walsh ML, Meason-Smith C, Arnold C, Suchodolski JS, Scott EM.The eye is host to myriad bacterial, fungal, and viral organisms that likely influence ocular surface physiology in normal and diseased states. The ocular surface mycobiota of horses has not yet been described using NGS techniques. This study aimed to characterize the ocular surface fungal microbiota (mycobiota) in healthy horses in 2 environmental conditions (stalled versus pasture). Conjunctival swabs of both eyes were obtained from 7 adult stallions stabled in an open-air pavilion and 5 adult mares living on pasture. Genomic DNA was extracted from ocular surface swabs and sequenced using pr...
Böske J, Wirth B, Garlipp F, Mumme J, Van den Weghe H.Energetic use of complex lignocellulosic wastes has gained global interest. Thermophilic digestion of horse manure based on straw was investigated using the upflow anaerobic solid-state (UASS) process. Increasing the organic loading rate from 2.5 to 5.5gvsL(-)(1)d(-)(1) enhanced the average methane production rate from 0.387 to 0.687LCH4L(-)(1)d(-)(1), whereas the yield decreased from 154.8 to 124.8LCH4kgvs(-)(1). A single-stage and two-stage process design showed almost the same performance. Compared to prior experiments at mesophilic conditions, thermophilic conditions showed a significantly...
Jay-Russell MT, Madigan JE, Bengson Y, Madigan S, Hake AF, Foley JE, Byrne BA.In July 2010, a horse from a rural farm (Farm A) in coastal Northern California was diagnosed with Salmonella Oranienburg infection following referral to a veterinary hospital for colic surgery. Environmental sampling to identify potential sources and persistence of Salmonella on the farm was conducted from August 2010 to March 2011. Salmonella was cultured using standard enrichment and selective plating. Pure colonies were confirmed by biochemical analysis, serotyped and compared by pulsed-field gel electrophoresis (PFGE) analysis. A total of 204 clinical and environmental samples at Farm A w...
Airaksinen S, Heiskanen ML, Heinonen-Tanski H.Increased stabling of horses near to cities has led to interest in the environmental effects of paddocks. In this study, the contamination of horse paddocks was examined by determining the nutrient and micro-organism contents in the surface run-off waters and the electrical conductivity, pH and phosphorus, potassium and nitrate contents of top soils. Two open-stable paddocks were studied, one cleaned and the other left uncleaned, with a stocking density of 37.5 animalsha(-1) in both. The feeding and drinking places were the most contaminated areas of both paddocks. In spring, after seven month...
Ferlazzo A, Cravana C, Fazio E, Medica P.In order to acquire a pattern of thyroid involvement in welfare maintenance in Ruminants and Equines, this review summarizes data concerning the reference values of total and free iodothyronines and their modifications in physiological conditions and in different management conditions (pregnancy, lactation, weaning, growth, isolation, restraint, shearing, confinement and transportation). Thyroidal and extrathyroidal tissues efficiently respond to management practices, giving a differentiated contribution to circulating iodothyronine changes. The hormonal response could be mainly attributed to ...
Vandenput S, Duvivier DH, Votion D, Art T, Lekeux P.The objective of this study was to test the hypothesis that stabled COPD horses can be maintained in clinical remission by replacing hay by grass silage and bedding made of wood shavings (Period B) and of wheat straw (Period C) during 6 weeks, respectively. At the end of these different periods, the pulmonary function of the horses was assessed by mechanics of breathing and arterial blood analyses. These results were compared to those measured in clinical remission obtained after 2 months in pasture (Period A). No significant difference was observed between these 3 periods neither to values ob...
Johnson E, Atwill ER, Filkins ME, Kalush J.Cryptosporidium parvum and Giardia duodenalis are now recognized as primary enteric pathogens in animals and humans. Regulatory agencies, such as the Environmental Protection Agency are under increasing pressure to reduce the concentration of these protozoa in surface waters. Given the popularity of recreational riding of horses on public land in California backcountry, concerns have been raised by various regulatory agencies as to whether horses used for backcountry recreation are a significant source of C. parvum and G. duodenalis for the environment. The prevalence of fecal shedding of Cryp...
Eronen JT, Evans AR, Fortelius M, Jernvall J.One of the classic examples of faunal turnover in the fossil record is the Miocene transition from faunas dominated by anchitheriine horses with low-crowned molar teeth to faunas with hipparionine horses characterized by high-crowned teeth. The spread of hipparionine horses is associated with increased seasonality and the expansion of open habitats. It is generally accepted that anchitheriine horses did not display an evolutionary increase in tooth crown height prior to their extinction. Nevertheless, to test whether anchitheriines showed any changes interpretable as adaptation to local condit...
Flegal AR, Gallon C, Hibdon S, Kuspa ZE, Laporte LF.Analyses of lead concentration and isotopic composition of recent and archived samples of the lace lichen (Ramalina menziesii) chronicle more than a century of atmospheric lead contamination in central California. The contamination extends back to our oldest sample from 1892, when lead levels in lichen from the northern reach of the San Francisco Bay estuary were 9-12 microg/g and their isotopic composition corresponded to those of high lead emissions from the Selby smelter (e.g., (206)Pb/(207)Pb = 1.165) that were killing horses in adjacent fields at that time. By the mid-1950s lead isotopic ...
Savill MG, Murray SR, Scholes P, Maas EW, McCormick RE, Moore EB, Gilpin BJ.Rhodococcus coprophilus, a natural inhabitant of herbivore faeces, has been suggested as a good indicator of animal (as opposed to human) faecal contamination of aquatic environments. However, conventional detection methods limit its use for this as they require up to 21 days to obtain a result. In this paper an optimised method for extracting R. coprophilus DNA from faecal samples is described. PCR and 5'-nuclease (TaqMan) PCR methods were developed to allow the detection and enumeration of R. coprophilus in faecal samples within 2-3 days. Both PCR methods targeted the 16S rRNA gene, producin...
Millerick-May ML, Karmaus W, Derksen FJ, Berthold B, Holcombe SJ, Robinson NE.Airway inflammation and mucus in the trachea are common in racehorses. Fine airborne particles can initiate and coarse particles can worsen airway inflammation in man and in animal models of airway disease. The regional and seasonal distribution of particles of different sizes has never been investigated in American racing stables. Objective: To determine the regional and seasonal concentration and number of airborne particles of different sizes in racing stables. Methods: Direct reading instruments were used to determine the mass concentration and numbers of particles 3 times daily (early mor...
Khan IU, Khairullah AR, Khan AY, Rehman AU, Mustofa I.This review explores advanced strategies for enhancing fertility and optimizing reproductive outcomes in equine breeding programs. Horses, being seasonal breeders, present unique reproductive challenges influenced by environmental and physiological factors such as photoperiods, hormone cycles, and aging. Key approaches discussed include hormonal therapies, artificial light manipulation, and nutritional supplementation to improve ovulation and conception rates during the breeding season. Specific hormones such as gonadotropin-releasing hormone analogs, equine follicle-stimulating hormone, and p...
Yarnell K, Le Bon M, Turton N, Savova M, McGlennon A, Forsythe S.To compare the rate of growth of four microbial strains that cause disease in the horse, on four commonly used types of bedding. The moisture-holding capacity of each bedding type was also tested. Results: Microbial strains included Streptococcus equi, Streptococcus zooepidemicus, Fusobacterium necrophorum, Dichelobacter nodosus and Dermatophilus congolensis. The bedding types tested were Pinus sylvestris (Scots pine shavings), Pinus nigra (Corsican pine shavings), Picea sitchensis (Sitka spruce shavings), Cannabis sativa (hemp) and chopped wheat straw. A suspension of each microbial strain wa...
Woodie B, Johnson AL, Grant B.Cervical vertebral stenotic myelopathy is a common cause of ataxia in horses secondary to spinal cord compression. Early articles describing this problem indicate genetic predisposition as a known risk factor. Further studies have shown the problem is a developmental abnormality which might have genetic predisposition and environmental influences.
Wolny-Koładka K.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...
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...
Wójcik E, Smalec E.The SCE test is often used as a sensitive and reliable technique in the biomonitoring of genotoxicity of mutagenic and carcinogenic agents. This study analysed the frequency of sister chromatid exchange in domestic horse chromosomes depending on the habitat and age of the analysed horses. The chromosome preparations were obtained from an in vitro culture of peripheral blood lymphocytes stained using the FPG technique. Both the habitat and the age significantly influence SCE frequency. A higher SCE incidence was observed in horses that lived in a large urban agglomeration than in those from the...
Stephen JO, Baptiste KE, Townsend HG.To describe clinical signs and clinicopathologic findings in donkeys with hypothermia. Methods: Retrospective study. Methods: 10 hypothermic donkeys. Methods: Information on signalment, history, physical examination findings, results of diagnostic tests, treatments, and necropsy findings was extracted from medical records of all donkeys with hypothermia between 1988 and 1998 and compared with information from medical records of all normothermic donkeys and hypothermic horses admitted to the hospital during the same period. Results: Donkeys were more likely to be hypothermic than horses. The me...
Clarke AF, Madelin TM, Allpress RG.The relationship between air hygiene within two types of identically managed horse housing and the incidence of covert respiratory disease (as revealed by endoscopic examination) of their inhabitants was assessed. The horses were all under the supervision of the same trainer. In one yard the design ensured the boxes were well ventilated in still air conditions. In the other yard the boxes were insulated and there was little provision for natural ventilation in still air conditions. There was heavy fungal and actinomycete contamination of wood shavings in the heavily insulated, poorly ventilate...
