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.
Ward NI, Savage JM.The elemental (Br, Cd, Cr, Cu, Mn, Ni, Pb, Se, V, and Zn) content of blood and wool or hair from animals (sheep, horses and alpacas) exposed to motor vehicle emissions alongside the London Orbital (M25) motorway is reported. Elemental values were determined by inductively coupled plasma mass spectrometry (ICP-MS) quality control assessment using flameless atomic absorption spectroscopy (for Pb, correlation coefficients of whole blood r = +0.87, and hair r = +0.82), and replicate (n = 10) analysis of the international reference material IAEA A13 Animal Blood. For Pb very good agreement was obta...
Lund RJ, Guthrie AJ, Killeen VM.Stables housing more than 20 horses in training were surveyed in the Pretoria, Witwatersrand, Vereeniging area of South Africa. Most racehorses were kept in loose boxes, bedded on straw or sawdust and remained indoors while the stables were cleaned. The average floor area was 13 m2 and airspace was 55 m3 per animal. The average predicted minimum air change rate by natural convection in calm winds was 7.0 air changes per hour, which was reduced to 2.2 when the doors and shutters were closed. The survey showed that many of the stables had been built without due consideration to factors that migh...
Letson GW, Bailey RE, Pearson J, Tsai TF.An Eastern equine encephalitis (EEE) outbreak in 1989 led to nine human and 196 equine cases, chiefly in coastal Atlantic and Gulf Coast counties. In the past two decades, EEE age-specific incidence and mortality rates have declined compared with earlier years. Analysis of rainfall patterns in areas where human EEE cases occurred between 1983 and 1989 revealed an association between occurrence of human cases and excess rainfall. The association was stronger with data from local weather stations than from statewide rainfall averages and the predictive models were best when applied to northern s...
Herd RP, Stinner BR, Purrington FF.Environmental consequences of treating horses with recommended dosages of ivermectin paste were studied in two controlled experiments with 29 horses in Ohio. In 1988, dung dispersal rates were measured by changes in dry weight over time of 48 copromes (300 g) formed from feces taken from four treatment and four control horses 3 days post ivermectin treatment. There was delayed dispersal of copromes from horses treated with ivermectin in June, resulting in significantly heavier ivermectin copromes compared with those of control horses by September. There was no difference in ivermectin or contr...
Woods PS, Robinson NE, Swanson MC, Reed CE, Broadstone RV, Derksen FJ.Airborne dust concentration (ADC) was measured in 2 different horse management systems using an Andersen cascade impactor in the box-stall, and a personal Marple cascade impactor attached to the halter to measure ADC in the breathing zone. The levels of aeroallergens implicated in chronic obstructive pulmonary disease were measured by radioallergosorbent-inhibition immunoassay. A conventional management system (System C) utilising hay feed and straw bedding, and a recommended environment (System R) utilising wood shaving bedding and a complete pelleted diet were studied. In the stall, total an...
Ullrey DE.Selenium was discovered 174 yr ago but, until 1957, was given little notice by biologists or was vilified as an agent that caused toxicity in grazing ruminants and horses in the northern Great Plains. After its status as an essential nutrient was established, Se received intense scrutiny, and hundreds of papers have been published dealing with its metabolic functions and the consequences of a Se deficiency. Because regions of Se deficiency are so extensive in the United States, great efforts have been made to gain Food and Drug Administration (FDA) approval for Se supplementation of animal die...
Rubes J, Borkovec L, Horínová Z, Urbanová J, Proroková I, Kulíková L.Cytogenetic examinations were carried out in 13 cattle farms, two herds of horses, one stag farm and 13 pig farms in areas with different levels of environmental contamination. The frequency of aberrant cells per 100 mitoses was 3.67 +/- 1.89 in pigs (n = 260) and 4.16 +/- 2.4 in herbivores (n = 497). This is a significant difference (p < 0.01). Ten times higher frequencies of chromatid exchanges were found in pigs. The examined herds were classified into three groups by the level of environmental contamination (satisfactory, impaired and severely impaired environment). Significant differen...
Sanada Y, Noda H, Nagahata H.Serological survey of Rhodococcus equi infection in horses in Hokkaido was performed using ELISA. Of 2,879 horse sera, 318 (11.0%) gave antibody-positive (OD greater than or equal to 0.3) reactions. The antibody-positive rate of female was significantly higher (p less than 0.01) than that of male, and no statistical difference between Anglo-Arab and thoroughbred was detected in the antibody-positive rate. The maximum antibody-positive rate (27.1%) was shown at 14 years of age. The antibody-positive rates on the 160 farms were found to vary widely from 0 to 78.9%. A significant difference (p le...
Kerkvliet NI, Wagner SL, Schmotzer WB, Hackett M, Schrader WK, Hultgren B.Investigations into the cause of health problems on a horse-breeding farm led to the discovery of high concentrations (630 to 9,810 mg/kg of bedding) of pentachlorophenol in wood shavings used as bedding for horses over a period of 2 to 4 years. Toxicologic signs in the horses were characteristic of toxic effects associated with exposure of polychlorinated dibenzo-p-dioxins and dibenzofurans. Tissue residue analysis confirmed presence of toxic polychlorinated dibenzo-p-dioxin and dibenzofuran isomers known to be in pentachlorophenol, substantiating the bioavailability of polychlorinated dibenz...
McClure SR, Chaffin MK, Beaver BV.Self-mutilative behavior, a form of stereotypic behavior, can be a serious problem in stallion management. An 11-year-old Quarter Horse stallion was referred for evaluation of repeated episodes of self-mutilation and aggressive behavior. Historically, this behavior worsened when the horse was isolated from other animals and confined to a stall for long periods. Observations of the stallion revealed episodes of self-mutilation and other forms of stereotypic behavior precipitated by stressful situations. Modification of this behavior was achieved by environmental and nutritional management and p...
Olenchock SA, Murphy SA, Mull JC, Lewis DM.Various work environments in agriculture naturally contain gram-negative bacteria and their endotoxins, which are heat stable, lipopolysaccharide-protein complexes that are integral parts of the outer membrane of gram-negative bacteria (1). Respiratory exposure to endotoxin-containing dusts has been associated with both an acute decline in pulmonary function (2) and chronic lung disease (3) in cotton dust-exposed subjects. Endotoxins can profoundly affect both humoral and cellular mediation systems in humans and experimental animals (4). One biologically active humoral system that is associate...
Doxey DL, Gilmour JS, Milne EM.Local weather patterns associated with 15 outbreaks of equine grass sickness in eastern Scotland were studied. The majority showed a trend toward cooler drier weather associated with irregular ground frosts. This would not preclude the hypothesis that fungi might be connected with the aetiology of grass sickness.
Rapp HJ, Weiss R, Bockisch FJ, Becker M, Stechele M.Using the direct sedimentation method, the air pollution with fungal spores was measured in indoor riding arenas and compared to horse stables, outside riding arenas and covered sport courts. Depending on the location of indoor arenas and stables, the presence of "dust-nests", the number of horses ridden, and the moisture of the tread layer, an air pollution was measured which was equivalent to that in stables except at times of feeding and straw-giving. Outside and in sport arenas a low air pollution was found. Recommendations are given, regarding optimum air hygiene especially for horses wit...
Pickrell J.Indoor atmospheres in swine or poultry confinement buildings, horse stalls or human dwellings contain gases, dusts and endotoxin in concentrations significantly in excess of those in outdoor environments. Although concentrations of such constituents differ appreciably between species, many of such differences may be related to differences in indoor mass loading and ventilation, or to the homogeneity of such ventilation. The high protein content of these indoor dust particles suggest they are of animal origin. Their ability to form bacterial colonies and to form or bind endotoxin suggest that t...
Flisińska-Bojanowska A, Gill J, Komosa M.1. The diurnal changes in the levels of lactic (LA) and pyruvic (PA) acids and values of pH were studied in standard-bred mares and their foals, for 13 weeks of foal life, throughout 2 years. 2. The studies began when a foal was 7 days old and were repeated every 2 weeks until foals reached 13 weeks of age. 3. Blood samples were taken every 4 hr for one day, each second week. 4. In the LA, PA levels and pH values no diurnal rhythm was stated in lactating mares during study periods. 5. In foals the diurnal rhythm in LA and PA occurred in the 3rd month of their life, with the acrophase at night ...
Cain PW, Jones JH, Smith BL.A remote data sampling cart has been designed and built for studying environmental factors that produce stress in horses during transportation. This dedicated sampling cart uses an XT-compatible mother board powered by a 12 V battery, with customized BIOS and ROM program. Sampling is performed using two digital and eight A/D (bipolar, differential) channels in burst mode at a frequency of 1 kHz. Digitized data are stored on magnetic tape for retrieval after the experiment. Configuration of sampling parameters is accomplished via a serial communications link to a host computer, and is stored in...
Floris B, Bini PP, Nuvole P, Di Meglio FG.The changes of some parameters in the blood serum of six Giara horses (3 males and 3 females) were checked weekly, in relation to the environmental temperature throughout a one winter and summer. T3, total lipids, triglycerides, urea nitrogen, creatinine, total protein, albumin, beta and gamma globulin showed significant difference between winter and summer and, with the exception of triglycerides, urea nitrogen and total protein were correlated to the environmental temperature. T4, glucose, uric acid and alpha globulin showed no difference between the two seasons and no correlation with the t...
Cymbaluk NF, Christison GI.Horses are reared in all types of weather. Temperatures as diverse as -40 degrees C to 40 degrees C are tolerated by horses. The nutrient requirement most influenced by cold weather is energy. In cold weather, feeding good quality hays free-choice is usually sufficient for mature horses in good body condition. Grain may have to be fed when poor quality hays are used. Hot weather (greater than 30 degrees C) necessitates heat loss to maintain body core temperature. Horses sweat to reduce body heat. Heat stress can be minimized by feeding diets that reduce the heat increment. Use of grain and fat...
Maylin GA, Bache CA, Lisk DJ.Effluents from a number of industries which are typically treated in municipal sewage plants result in cadmium-containing sludge. Disposal of such sewage sludge by application to agricultural land can result in uptake of cadmium by crops. In this study, oats were grown on soils which had been amended with sewage sludge from Syracuse, New York. The cadmium concentration in the sludge-grown oats was 1.79 ppm dry weight. Horses were fed the sludge-grown oats for 6 weeks during which time blood samples were taken for the determination of cadmium. No significant differences (p greater than 0.05) we...
Ripatti T, Koskela P, Kotimaa M, Koskinen E, Mäenpää PH.Over periods of 22 and 14 months, IgG antibody concentrations in serum samples obtained monthly from 14 mares and 19 foals, respectively, were measured by use of ELISA against antigens of the following environmental microbes: Aspergillus umbrosus, Penicillium brevicompactum, Rhodotorula glutinis, Absidia corymbifera, Aspergillus fumigatus, Humicola grisea, Micropolyspora faeni, and Thermoactinomyces vulgaris. The mares and foals were on pasture from early June until early October, then were stabled during the winter season until the following June. In the mares, increased antibody concentratio...
Ostrowski SR, Gunter EW, Matte TD.During the course of an investigation into community lead poisoning near a secondary lead smelter in Jamaica, blood lead and zinc protoporphyrin levels were measured in 8 exposed and 6 (3 Jamaican, 3 US) unexposed donkeys and mules. The blood lead levels of 6 animals in the contaminated area ranged from 7.5 to 33 micrograms/dl (mean = 17.6 micrograms/dl), compared to 1.8 and 2.4 in unexposed Jamaican animals. More striking was the difference in zinc protoporphyrin levels; all 8 exposed donkeys and mules had values between 900 and 1890 micrograms/dl, compared with a range of 34-46 micrograms/dl...
Dixon PM, McGorum B.Two horses on separate farms developed severe obstructive pulmonary disease in successive years during the early summer months. In both cases clinical remission of the respiratory distress was achieved by moving the animals to different environments. The suggested aetiology for this outdoor chronic respiratory disease is a pulmonary allergy to pollen. Both animals were also shown to suffer from classical chronic obstructive pulmonary disease, i.e., obstructive pulmonary disease in the presence of hay and, or, straw.
Hutchinson GW, Abba SA, Mfitilodze MW.Longevity in faeces, migration to and survival on herbage of mixed strongyle infective larvae (approximately 70% cyathostomes: 30% large strongyles) from experimentally deposited horse faeces was studied in the dry tropical region of North Queensland for up to 2 years. Larvae were recovered from faeces deposited during hot dry weather for a maximum of 12 weeks, up to 32 weeks in cool conditions, but less than 8 weeks in hot wet summer. Translation to herbage was mainly limited to the hot wet season (December-March), except when unseasonal winter rainfall of 40-50 mm per month in July and Augus...
Anke M, Kośla T, Groppel B.The Cd status of animals is best reflected by kidneys and much worse by liver and hair. Breed (heavy- and warm-blooded horses) only took an insignificant effect on the Cd content of kidneys and liver. On the average, however, warm-blooded horses stored more Cd than heavy ones. Geldings from Cd-exposed living areas accumulated insignificantly more Cd in liver, kidneys and hair than mares. The influence of age on the Cd content of kidneys and liver of Cd-exposed horses was significant. The Cd exposure of a living area was very well reflected by kidneys and liver. On the average, horses from two ...
Kośla T, Anke M, Grün M.The breed of horses took a significant effect on the Pb content of animals with a normal Pb supply. Warm-blooded horses stored more Pb in skeleton, kidneys, liver and cerebrum than heavy horses. The sex only had the trend of influencing the Pb status. Mares with a normal Pb supply incorporated more Pb than geldings. Age only took a slight effect on the skeleton. Older horses stored more Pb in the metatarsal bone than younger ones. The Pb content of horse meat was not influenced by Pb exposure. Pb was not additionally deposited in the musculature. The Pb offer of the living area took a signific...
Hartung J, Klinckmann G, Adrian U.Dust in horse barns is assumed to contribute to pulmonary disease, it is attempted to reduce the airborne dust by soaking or sprinkling the hay before feeding. Both means cause considerable efforts and increase the relative humidity of the air. This is why a commercial dust-binding agent (Revesto pur) was used in a pilot investigation which was carried out during 2 weeks - one week for control and one week using the agent - in a private horse barn where three horses were regularly stable. The airborne dust was measured by a continuously working instrument. Once a day (7.00 a.m.) the number of ...
Sambraus HH, Radtke K.Studies were made on 27 horses which were known to weave. They were stallions, mares and geldings between the ages of 3 and 22 years. The horses were individually observed for several days in their habitual surroundings. A period, in which a horse makes pauses of not more than ten minutes, is considered a weaving phase. Shorter pauses subdivide the weaving phase into weaving series. The basic unit of weaving is the weaving displacement, i.e. the head movement between the turning points. The number of daily weaving displacements of the horses examined varied from less than 400 up to almost 18,0...
Hartung J, Klinckmann G, Adrian U.Dust in horse barns is assumed to contribute to pulmonary disease, it is attempted to reduce the airborne dust by soaking or sprinkling the hay before feeding. Both means cause considerable efforts and increase the relative humidity of the air. This is why a commercial dust-binding agent (Revesto pur) was used in a pilot investigation which was carried out during 2 weeks - one week for control and one week using the agent - in a private horse barn where three horses were regularly stable. The airborne dust was measured by a continuously working instrument. Once a day (7.00 a.m.) the number of ...
Geburek F, Deegen E, Hewicker-Trautwein M, Ohnesorge B.Verrucous pastern dermatitis is a chronic hyperplastic dermatopathy of the feet of horses which is characterized by a greasy, odorous coating of the skin and, in advanced stages, by clearly demarcated calluses and wart-like proliferations. The disease occurs almost exclusively in cold-blooded and other heavy horses, with certain breeds affected most frequently. It is considered a distinct disease entity within the framework of pastern dermatitis syndrome. There is no consensus in the literature about relationship of the disease to the sex and age of the horse. Horses with a high cannon circumf...
de Jesús Tello-Pasos A, González-Pech PG, Blanco-Molina JM.The aim of this observational study was to describe the characteristics of circuits performed by horses used in carriage tourism in a tropical city and discuss their implications as a challenge for animal welfare. The tourism circuit of 33 Criollo horses (400 ± 50 kg) was followed by using the GPS from August 31 to December 2nd, 2018, in the rainfall summer season. The environmental temperature, humidity, and accumulated rainfall were obtained from a local meteorological station. The distance and number of trips, the number of people transported, and the time taken for working and resting ac...
Inácio CT, Magalhães AMT, Souza PO, Chalk PM, Urquiaga S.Variations in the relative isotopic abundance of C and N (δC and δN) were measured during the composting of different agricultural wastes using bench-scale bioreactors. Different mixtures of agricultural wastes (horse bedding manure + legume residues; dairy manure + jatropha mill cake; dairy manure + sugarcane residues; dairy manure alone) were used for aerobic-thermophilic composting. No significant differences were found between the δC values of the feedstock and the final compost, except for dairy manure + sugarcane residues (from initial ratio of -13.6 ± 0.2 ‰ t...
van Grevenhof EM, Gezelle Meerburg ARD, van Dierendonck MC, van den Belt AJM, van Schaik B, Meeus P, Back W.Osteochondrosis (OC) is a common, clinically important joint disorder in which endochondral ossification is focally disturbed. Reduced blood supply to growing cartilage is considered an important cause of the condition, which has both genetic and environmental origins. Housing conditions can influence cartilage injury through peak-pressure changes during limb sliding. Additionally, circulatory perturbation can cause the avascular necrosis of cartilage. In this study, we evaluated the type and frequency of limb sliding during standing up and the occurrence of OC in foals aged up to 12 months o...
Delvescovo B, Mullen KR, Eicker SW, Ivanek R, Ainsworth DM.Previously we described a clustering of dysphagic foal cases on a Pennsylvania (PA) Standardbred farm which was associated with exposure of pregnant mares to high concentrations of polycyclic aromatic hydrocarbons (PAHs) in the well water. The effect of dysphagia on future athleticism was uncertain. Objective: To determine if, as adults, dysphagic foals were less likely to race and if athleticism (age of first race, Speed Index and Earnings Per Start Index) differed from that of healthy foals that raced as adults. Methods: Prospective cohort study. Methods: All foals born during the study peri...
Anna C, Martyna P, Marcin S, Dawid W.Free-ranging grazers are increasingly being introduced to areas of high natural value, such as wetlands. There is also growing attention that has been paid to the historical role of herbivores in shaping ecosystems and landscapes. Even though studies on the grazing of free-range horses were carried out in different regions and climates, still little is known about their habitat selection on heterogeneous marshy areas in the temperate region of Europe. The aim of this study was to investigate the habitat use by contemporary Konik horses during the growing season on the basis of three-year GPS d...
Kagan IA.Temperate grasses contain both water- and ethanol-soluble carbohydrates. Water-soluble carbohydrates (WSCs) of temperate grasses include glucose, fructose, sucrose, and fructans (fructose-based polymers) of varying lengths. Ethanol-soluble carbohydrates (ESCs) consist of glucose, fructose, sucrose, and shorter fructans. WSCs and ESCs have been implicated in equine pasture-associated laminitis and other metabolic disorders. In this paper, the peer-reviewed literature of the past decade was summarized for selected factors influencing concentrations and composition of WSCs and ESCs in temperate g...
Kampmann S, Hampson BA, Pollitt CC.Recent record rainfall in much of semi-arid Central Australia is the most likely reason for a feral horse population increase in excess of normal. Uncontrolled numbers of feral horses have habitat degradation and animal welfare implications. Objective: The aims of this study were to investigate the social structure of feral horses and assess their population growth rate following unseasonably high rainfall. Methods: The study area was 4000 km(2) of unmanaged, semi-arid country in Central Australia (latitude 24.50°S, longitude 132.10°E). Horses were identified by descriptive features from g...
Daly AE, Deible CG, Lamb CE, Santacaterina SM, Marzolf NL, Page AE, Horohov DW, Wood PL, Werre SR, Chapman SE, Christmann U.To evaluate surfactant protein D (SP-D) concentrations in serum and bronchoalveolar lavage fluid (BALF) from young healthy horses on pasture or housed in a typical barn. Methods: 20 young healthy horses. Methods: Horses were randomly assigned to 1 of 2 groups (pasture, n = 10; barn, 10), and serum and BALF samples were collected for SP-D determination at baseline (all horses on pasture) and 2 weeks and 4 weeks after the barn group of horses was relocated from the pasture to the barn. Other evaluations included physical and tracheoscopic examinations. Findings were compared within and between g...
Thomson JR, McPherson EA.The effects of environmental control on horses affected with chronic obstructive pulmonary disease was assessed by clinical examination and pulmonary function tests, ie, maximum change in intrathoracic pressure, tidal volume, minute volume, non-elastic work of breathing, dynamic compliance, inspiratory and expiratory flow rates and arterial blood gas analysis. A controlled environment (ie, bedding horses on shredded paper and feeding a complete cubed diet) caused symptomatic COPD affected horses to become asymptomatic within four to 24 days (mean +/- sd 8.4 +/- 4.8 days). When asymptomatic, th...
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...
Maylin GA, Bache CA, Lisk DJ.Effluents from a number of industries which are typically treated in municipal sewage plants result in cadmium-containing sludge. Disposal of such sewage sludge by application to agricultural land can result in uptake of cadmium by crops. In this study, oats were grown on soils which had been amended with sewage sludge from Syracuse, New York. The cadmium concentration in the sludge-grown oats was 1.79 ppm dry weight. Horses were fed the sludge-grown oats for 6 weeks during which time blood samples were taken for the determination of cadmium. No significant differences (p greater than 0.05) we...
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...
Weese JS, Yu AA.Bacterial, dermatophilosis, and superficial ringworm infections are common skin diseases noted in equine dermatology. The ability to recognize and accurately diagnose the skin condition is key to selecting an appropriate and successful treatment regimen. Addressing underlying etiology, environmental management, and infection control play a crucial role in preventing relapse of clinical signs.
Beythien E, Aurich C, Wulf M, Aurich J.Seasonal changes in metabolic rate have been shown in horses and we hypothesized that this leads to the birth of smaller foals early in the year. Mares and their foals were assigned to three groups by day of foaling within the year (e.g. 1 January = day 1): Group 1 (n = 10) day 40-65, group 2 (n = 8) day 67-92, group 3 (n = 9) day 94-121. Groups did not differ with regard to parity. In foals, height at withers and body weight were determined on days 1-5 and weekly until 12 weeks of age. Chest circumference, distances fetlock to carpus, carpus to elbow, poll to nose and crown-rump lengt...
Floris B, Bini PP, Nuvole P, Di Meglio FG.The changes of some parameters in the blood serum of six Giara horses (3 males and 3 females) were checked weekly, in relation to the environmental temperature throughout a one winter and summer. T3, total lipids, triglycerides, urea nitrogen, creatinine, total protein, albumin, beta and gamma globulin showed significant difference between winter and summer and, with the exception of triglycerides, urea nitrogen and total protein were correlated to the environmental temperature. T4, glucose, uric acid and alpha globulin showed no difference between the two seasons and no correlation with the t...
Tyler CR, Filby AL, Bickley LK, Cumming RI, Gibson R, Labadie P, Katsu Y, Liney KE, Shears JA, Silva-Castro V, Urushitani H, Lange A, Winter MJ....Many factors have been considered in evaluations of the risk-benefit balance of hormone replacement therapy (HRT), used for treating menopausal symptoms in women, but not its potential risks for the environment We investigated the possible environmental health implications of conjugated equine estrogens (CEEs), the most common components of HRT, including their discharge into the environment, their uptake, potency, and ability to induce biological effects in wildlife. Influents and effluents from four U.K. sewage treatment works (STWs), and bile of effluent-exposed fish, were screened for six ...
BOYD WL, BOYD JW.Boyd, William L. (Ohio State University, Columbus) and Josephine W. Boyd. Viability of coliform bacteria in antarctic soil. J. Bacteriol. 85:1121-1123. 1963.-The distribution of coliform bacteria in soils of Ross Island and the nearby mainland was studied. None was found in almost all of the samples collected, including some from the Adelie penguin rookeries at Cape Royds and Cape Crozier and in soil at the McMurdo Base which had been recently contaminated by human sewage. Samples of pony manure left from previous expeditions were also negative, with one exception where Escherichia coli were p...
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...
Boysen C, Davis EG, Beard LA, Lubbers BV, Raghavan RK.Kansas witnessed an unprecedented outbreak in Corynebacterium pseudotuberculosis infection among horses, a disease commonly referred to as pigeon fever during fall 2012. Bayesian geostatistical models were developed to identify key environmental and climatic risk factors associated with C. pseudotuberculosis infection in horses. Positive infection status among horses (cases) was determined by positive test results for characteristic abscess formation, positive bacterial culture on purulent material obtained from a lanced abscess (n = 82), or positive serologic evidence of exposure to organism ...
Brinkmann L, Riek A, Gerken M.Domesticated horses are increasingly kept under semi-natural housing conditions, whereas their adaptation capacity is not fully investigated. In all, 10 Shetland pony mares were held under semi-extensive conditions for 1 year. In winter animals were allocated into two feeding groups (60% and 100% of maintenance energy requirement, respectively). Triiodothyronine, thyroxine, non-esterified fatty acids (NEFA), total bilirubin, total protein, triglyceride, glucose, insulin and hair length were measured at monthly intervals, whereas BW, body condition score, cresty neck score and resting heart rat...
Evans-Clay M, Porch N, Maguire G, Weston MA.Beaches are under increasing pressure from a wide range of anthropogenic threats, including human trampling, vehicular crushing, and horse riding/training. The impacts of horses on beaches are unknown. We index the relative abundance, diversity and assemblage composition of beach invertebrates at paired sites with and without horses at nine beaches (locations) across Victoria, Australia. Horses were more common at sites where they were allowed and sites (horse versus no horse) within beaches were well matched, having similar slope, seaweed coverage, human and dog activity-attributes which vari...
Flisińska-Bojanowska A, Gill J, Komosa M.1. The diurnal changes in the levels of lactic (LA) and pyruvic (PA) acids and values of pH were studied in standard-bred mares and their foals, for 13 weeks of foal life, throughout 2 years. 2. The studies began when a foal was 7 days old and were repeated every 2 weeks until foals reached 13 weeks of age. 3. Blood samples were taken every 4 hr for one day, each second week. 4. In the LA, PA levels and pH values no diurnal rhythm was stated in lactating mares during study periods. 5. In foals the diurnal rhythm in LA and PA occurred in the 3rd month of their life, with the acrophase at night ...
Alinovi CA, Ward MP, Couëtil LL, Wu CC.To assess methods of detecting environmental contamination with Salmonella organisms and evaluate a cleaning and disinfection protocol for horse stalls in a veterinary teaching hospital. Methods: Original study. Methods: 37 horses with diarrhea likely to be caused by Salmonella infection and their stall environments. Methods: Fecal samples were collected from horses daily during hospitalization; samples were obtained from stall sites after cleaning and application of disinfectants. Fecal and environmental samples were cultured for Salmonella spp and tested via polymerase chain reaction (PCR) a...
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...
Vaziri GJ, Jones MM, Carr HA, Nuñez CMV.The disruption of animals' symbiotic bacterial communities (their microbiota) has been associated with myriad factors including changes to the diet, hormone levels, and various stressors. The maintenance of healthy bacterial communities may be especially challenging for social species as their microbiotas are also affected by group membership, social relationships, microbial transfer between individuals, and social stressors such as increased competition and rank maintenance. We investigated the effects of increased social instability, as determined by the number of group changes made by femal...
Reeves WK, Miller MM.Organic insect repellents are of interest to many agricultural producers and animal owners. Geraniol, a plant-derived alcohol, is naturally produced by a wide range of plants and is a US Environmental Protection Agency minimum risk pesticide. Previous studies have shown various concentrations of geraniol repel or kill mosquitoes; however, geraniol might cause allergic contact dermatitis in humans or animals. We tested a commercially available 2% aqueous solution of geraniol on ponies as a mosquito repellent. Five trials were conducted on ponies treated with a 60-ml aerosol mist (30 ml per side...
Weaver RW, Entry JA, Graves A.Livestock are known contributors to stream pollution. Numbers of fecal streptococci and Escherichia coli in manure naturally deposited by livestock in the field are needed for activities related to bacterial source tracking and determining maximum daily bacterial loading of streams. We measured populations of fecal streptococci and E. coli in fresh and dry manure from cattle (Bos taurus L.), horses (Equus caballus L.), and sheep (Ovis aires L.) on farms in southern Idaho. Populations of indicator bacteria in dry manure were often as high as that in fresh manure from horse and sheep. There was ...
