"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Hoff RB, Molognoni L, Deolindo CTP, de Oliveira T, Mattos JLS, Oliveira LVA, Daguer H.Sugarcane yeast and brewer's yeast from ethanol production are widely used as ingredients of animal feed formulations in Brazil. To avoid the contamination of the must in ethanol production refineries, the use of antibiotics is one of the main preventive treatments. Thus, there is a risk of antibiotic residues carry over from yeast to animal feed. This unintentional addition of antibiotics can produce non-compliant feed products, due to regulatory aspects and their toxicity for animals. The results of an exploratory program to assess the occurrence of over 60 antibiotics and other pharmaceutic...
Clayton HM, Hobbs SJ.The piaffe is an artificial, diagonally coordinated movement performed in the highest levels of dressage competition. The ground reaction forces (GRFs) of horses performing the piaffe do not appear to have been reported. Therefore, the objective of this study was to describe three-dimensional GRFs in ridden dressage horses performing the piaffe. In-ground force plates were used to capture fore and hindlimb GRF data from seven well-trained dressage horses. Peak vertical GRF was significantly higher in forelimbs than in the hindlimbs (7.39 ± 0.99 N/kg vs. 6.41 ± 0.64 N/kg; < 0.001) with ve...
Fikes KK, Coverdale JA, Leatherwood JL, Campbell JM, Welsh TH, Hartz CJ, Goehring M, Millican AA, Bradbery AN, Wickersham TA.Twenty-seven mature Quarter horses were used in a randomized design to determine the effects of bioactive protein supplementation on gait kinematics and systemic inflammatory markers in a 34-d trial. Treatments consisted of oral doses of 230 g/d of pelleted supplements containing 0 g (CON; = 9), 40 g of bioactive protein (40BP; = 9; LIFELINE, APC, LLC, Ankeny, IA), and 80 g of bioactive protein (80BP; = 9) daily. Horses were fed a commercial concentrate at 0.5% BW (as-fed) and received coastal bermudagrass () hay daily. On day 33, horses consistent in exercise (CON, = 6; 40BP, = 8; 80BP,...
Nowacka-Woszuk J, Mackowski M, Stefaniuk-Szmukier M, Cieslak J.The equine graying with age causative mutation in the syntaxin-17 gene (STX17) has been known for over a decade, but proper genotyping of this variant remains challenging due to its molecular character (4.6-kb tandem duplication). Precise information on gray mutation status is important for horse breeders and veterinarians, since gray homozygous horses are more prone to developing aggressive melanoma tumors than heterozygotes. Since recent studies have confirmed that droplet digital PCR is a valuable technique for copy number analysis, we decided to investigate whether this method can be used ...
Story MR, Haussler KK, Nout-Lomas YS, Aboellail TA, Kawcak CE, Barrett MF, Frisbie DD, McIlwraith CW.Interest in the cervical spine as a cause of pain or dysfunction is increasingly becoming the focus of many equine practitioners. Many affected horses are presented for poor performance, while others will present with dramatic, sometimes dangerous behavior. Understanding and distinguishing the different types of neck pain is a starting point to comprehending how the clinical presentations can vary so greatly. There are many steps needed to systematically evaluate the various tissues of the cervical spine to determine which components are contributing to cervical pain and dysfunction. Osseous s...
Cooper CJ, Arroyo LG, Pearl DL, Hewson J, Lillie BN.A survey of Ontario horse breeders was conducted in 2016 and retrospectively asked farm-level management questions regarding herd sizes, vaccination, respiratory disease, and abortion over the years 2014 to 2015. A total of 88 farm owners completed the survey, reporting 857 broodmares. Using logistic regression modelling, management influences on vaccine use, and the reporting of respiratory disease or abortion was investigated. Having veterinary records and the reasons for breeding were significantly associated with the odds of an abortion even after controlling for broodmare herd size. The o...
Ribeiro RM, Ribeiro DS, Cota LO, Leme FO, M Carvalho A, Faleiros RR.This study aimed to characterize and correlate physiological and metabolic changes in horses fed a hypercaloric diet (HD). Nine mature horses with a mean initial body condition score of 2.9 ± 1 (scale, 1-9) were fed a high-calorie diet for 5 months. Fasting blood samples were collected before the study and biweekly for the duration of the project to determine the concentrations of cholesterol (CHOL), very low (VLDL), low (LDL) and high-density (HDL) lipoproteins, triglycerides, non-esterified fatty acids, and fructosamine. A low-dose oral glucose tolerance test (LGTT) was conducted before, 75...
Mrugala D, Leatherwood JL, Morris EF, Dickson EC, Latham CM, Owen RN, Beverly MM, Kelley SF, White-Springer SH.Conjugated linoleic acid (CLA) improves oxidative stress and mitochondrial biogenesis in various species but has not been thoroughly investigated in horses. We collected blood and muscle samples from lightly exercising horses before and 6 and 12 wk after receiving either soybean oil (CON; n = 5) or CLA (CLA; n = 5) supplementation. Samples were analyzed for markers of mitochondrial characteristics, antioxidant status, oxidative stress, and muscle damage. Data were analyzed using a linear model with repeated measures. In the triceps brachii (TB), citrate synthase (CS) activity was higher in CON...
Giusto G, Cerullo A, Labate F, Gandini M.Incomplete ileocecal bypass can be performed in cases in which an ileal disfunction is suspected but resection of the diseased ileum is not necessary. Objective: To describe the clinical findings, the surgical technique, and the outcome of 21 cases of colic with ileal pathologies that underwent an incomplete ileocecal bypass. Methods: Historical, clinical, and surgical features of cases diagnosed with pathologies involving the ileum or the ileocecal valve that underwent ileocecal anastomosis without ileal resection were retrieved. Clinical (heart rate, duration of symptoms, presence of reflux,...
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...
Shnaiderman-Torban A, Marchaim D, Navon-Venezia S, Lubrani O, Paitan Y, Arielly H, Steinman A.In human medicine, infections caused by third-generation cephalosporin-resistant (3GCRE) are associated with detrimental outcomes. In veterinary medicine, controlled epidemiological analyses are lacking. A matched case-case-control investigation (1:1:1 ratio) was conducted in a large veterinary hospital (2017-2019). In total, 29 infected horses and donkeys were matched to 29 animals with third-generation cephalosporin-susceptible (3GCSE) infections, and 29 uninfected controls (overall = 87). Despite multiple significant associations per bivariable analyses, the only independent predictor fo...
Jackson K, Kelty E, Tennant M.Equine peripheral caries can cause significant morbidity and can have considerable welfare implications. Recent research suggests that diets with high water soluble carbohydrate (WSC) content are associated with high risk of peripheral caries. Previous work has indicated that the condition may be treatable if the inciting cause is removed and the damaged tooth allowed to erupt out, being replaced by the unaffected tooth previously under the gingival margin. Objective: To see whether the peripheral caries process can be ceased if oaten hay (typically high WSC) is removed from the diet and repla...
Bannai H, Tominari M, Kambayashi Y, Nemoto M, Tsujimura K, Ohta M.Antibody response in horses after accelerated-schedule Getah virus vaccination was evaluated for its potential adoption during outbreaks. One-year-old Thoroughbred horses received two doses of priming vaccinations following an accelerated schedule (accelerated group: 14-day interval, n = 30) or the conventional schedule (control group: 28-day interval, n = 30). At Day 14, both groups showed similar seropositive rates (66.7% in control group and 73.3% in accelerated group) and geometric mean (GM) virus-neutralizing titers (5.2 [95% confidence interval (CI), 3.0-8.8] in control group and 5.3...
Al-Majhali SH, Khairuddin NH, Abdul Razak IS, Radzi Z, Rahman MT, Sapalo JT, Mayaki AM, Czernuszka JT.The use of a self-inflating tissue expander is a technique to stretch cutaneous tissues for potential use in reconstructive skin surgeries. This study investigates the mechanical properties of horse skin stretched by the subcutaneous implantation of anisotropic tissue expanders at the forehead, right shoulder, and dorsomedial part of the cannon region of the right forelimb in six (n = 6) horses. After 14 days of skin expansion, expanded and normal (control) skin samples were harvested and their mechanical properties of elastic modulus (EM), maximum force (MF), maximum stress (MSs) and maximu...
Oláh T, Cai X, Michaelis JC, Madry H.The human knee is a complex joint, and affected by a variety of articular cartilage disorders. Large animal models are critical to model the complex disease mechanisms affecting a functional joint. Species-dependent differences highly affect the results of a pre-clinical study and need to be considered, necessitating specific knowledge not only of macroscopic and microscopic anatomical and pathological aspects, but also characteristics of their individual gait and joint movements. Methods: Literature search in Pubmed. Conclusions: This narrative review summarizes the most relevant anatomical s...
Pomorska-Zniszczyńska A, Szczepanik M, Kalisz G.Videodermoscopy is a novel, noninvasive technique used to examine the appearance of skin and its adnexa. The aim of this study was to assess specific dermoscopic parameters in Arabian purebred mares in particular areas of the body during the winter season. The study was performed in the winter season. Videodermoscopic evaluations of the hair and skin were performed over seven areas of the body: the forehead, mane, neck, chest, flank, croup, and tail. Twenty-one healthy, non-breeding Arabian mares aged 3 to 21 years were selected for the study. The Video-Dermatoscope Vidix 7 (Medici Medical SRL...
Bustos CP, Dominguez JE, Garda D, Moroni M, Pallarols Molinari N, Herrera M, Chacana PA, Mesplet M.Salmonella spp. causes digestive clinical signs in horses. Foals and hospitalized animals are more susceptible to the disease. Nowadays, the report of multidrug-resistant Salmonella spp. producer of extended-spectrum β-lactamases, is more frequent. The aim of this work was to study the clonal relationship and antimicrobial susceptibility profiles among Salmonella ser. Typhimurium isolates, obtained during a salmonellosis outbreak in an Argentinian equine hospital. Thus, in 2017, we studied the genotypic profiles and the susceptibility to antimicrobials of the strains isolated from three anima...
Thompson AC, Mochal-King C.Hypoparathyroidism is an uncommon endocrine disorder in the horse characterized by a transient or permanent parathyroid hormone insufficiency. Hypoparathyroidism is associated with hypocalcemia and hyperphosphatemia, primarily presenting with clinical signs consistent with hypocalcemia. This case report describes clinical presentation and treatment of a horse with severe hypocalcemia due to primary hypoparathyroidism. A 17-year-old, 542 kg Quarter Horse gelding presented for shaking and tremors. Significant findings include generalized muscle fasciculations, synchronous diaphragmatic flutter, ...
Fedorka CE, Ball BA, Wynn MAA, McCormick ME, Scoggin KE, Esteller-Vico A, Curry TE, Kennedy LA, Squires EL, Troedsson MHT.Preterm labor and/or abortion causes considerable economic impact on the equine industry. Unfortunately, few experimental models exist for the induction of various pregnancy-related complications, and therefore extrapolations are made from the experimental model for ascending placentits, although inferences may be minimal. Certain steroid hormones (progestogens, estrogens) and fetal proteins (alpha-fetoprotein; AFP) might improve the diagnostics for abnormal pregnancy, but the utility of these markers in the field is unknown. To assess this, thoroughbred mares (n = 702) were bled weekly begi...
Narciso MHPM, da Luz MPF, Maia CM, Filho JNPP.Little is known about the dominance and leadership behaviors in the social structure of mules (Equus caballus × Equus asinus). Based on the frequency of threat and aggressive behaviors, we compared the social structure, dominance, and leadership of independent groups of mules and horses (n = 11 per group), and filmed the frequency of these behaviors over a period of four days. In both groups, aggressions were uncommon and, when based on threats, the social structure was linear and consistent with males ranking higher in dominance. When compared to horses, mules exhibited some agonistic so...
Studer N, Bernal SD, Thormann W, Levionnois O, Spadavecchia C.To evaluate the antinociceptive effect of a bolus of intravenous levomethadone administered to horses during romifidine constant rate infusion (CRI). Methods: Prospective, randomized, masked, crossover experimental study. Methods: A group of eight adult Warmblood horses (seven geldings, one mare) aged 6.6 ± 4.4 years, weighing 548 ± 52 kg [mean ± standard deviation (SD)]. Methods: Levomethadone 0.1 mg kg or an equivalent volume of saline (control) was administered intravenously to standing horses 60 minutes after starting a romifidine CRI. Blood samples to quantify romifidine and levomethad...
Thorsteinsdóttir L, Guðmundsson GÖ, Jensson H, Torsteinsdóttir S, Svansson V.Equine coital exanthema (ECE) caused by equid alphaherpesvirus 3 (EHV-3) is a contagious venereal disease. It is characterized by the formation of papules, vesicles, pustules and ulcers on the external genitals of both mares and stallions. The Icelandic horse is the only breed in Iceland and has lived isolated in the country for over 1000 years. Three types of equine herpesviruses (EHV) have been found in Iceland, EHV-4, EHV-2 and EHV-5, while EHV-1 has never been detected. Symptoms resembling ECE have previous been observed in horses in Iceland, arousing suspicion of EHV-3 infection, but thi...
Weatherall KM, Boone LH, Munsterman A, Hanson RR.To determine the compressive effect of abdominal bandages after ventral midline celiotomy closure in horses. Methods: Ex vivo, experimental study. Methods: Equine cadavers (n = 18), six per group. Methods: A 20-cm ventral midline celiotomy was created in each of 18 equine cadavers. A 200-L inflatable bladder was placed in the abdomen, and the linea alba was apposed. Horses were randomly assigned to no bandage (C), elastic (E), or Velcro inelastic (I) bandage groups for testing. Circumferential bandages were placed with a subbandage pressure monitoring system over the incision. The bladder was ...
Dalla Costa E, Dai F, Lecchi C, Ambrogi F, Lebelt D, Stucke D, Ravasio G, Ceciliani F, Minero M.Pain in horses is an emergent welfare concern, and its assessment represents a challenge for equine clinicians. This study aimed at improving pain assessment in horses through a convergent validation of existing tools: we investigated whether an effective analgesic treatment influences the horse grimace scale (HGS) and the concentration of specific circulating microRNAs (miRNAs). Eleven stallions underwent routine surgical castration under general anaesthesia. They were divided into two analgesic treatment groups: castration with the administration of preoperative flunixin and castration with ...
Kareskoski M, Vakkamäki J, Laukkanen K, Palviainen M, Johannisson A, Katila T.Matrix metalloproteinase (MMP)-2 and MMP-9 are gelatinases that take part in several reproductive processes. The aim of this study was to measure levels of MMP-2 and MMP-9 in fractionated stallion ejaculates, and to evaluate the association between these components and semen quality, and sperm longevity during cooled storage. Semen quality were assessed separately for sperm-rich fractions (HIGH), sperm-poor fractions (LOW), and whole ejaculate samples (WE) from 33 stallions. After cooled storage with SP either present or removed, sperm motility and DFI were determined. The relative activity of...
Dalla Costa E, Dai F, Lecchi C, Ambrogi F, Lebelt D, Stucke D, Ravasio G, Ceciliani F, Minero M.Pain in horses is an emergent welfare concern, and its assessment represents a challenge for equine clinicians. This study aimed at improving pain assessment in horses through a convergent validation of existing tools: we investigated whether an effective analgesic treatment influences the horse grimace scale (HGS) and the concentration of specific circulating microRNAs (miRNAs). Eleven stallions underwent routine surgical castration under general anaesthesia. They were divided into two analgesic treatment groups: castration with the administration of preoperative flunixin and castration with ...
Poyato-Bonilla J, Sánchez-Guerrero MJ, Cervantes I, Gutiérrez JP, Valera M.Measurements from 13 different morphological traits of importance in the Pura Raza Español (PRE) horse were used to estimate genetic and environmental parameters following a heteroscedastic model in which data were assigned to stallions. Data sets used ranged from 20,610 (height at withers) to 48,486 measurements (length of shoulder), and the number of animals analysed in the pedigrees varied from 17,662 (height at withers) to 23,962 (dorsal-sternal diameter). Results of heritabilities of the traits varied from 0.09 (width of chest and upper neck line) to 0.30 (muscular development). Further,...
Broberg MN, Knych H, Bondesson U, Pettersson C, Stanley S, Thevis M, Hedeland M.Selective Androgen Receptor Modulators (SARMs) have anabolic properties but less adverse effects than anabolic androgenic steroids. They are prohibited in both equine and human sports and there have been several cases of SARMs findings reported over the last few years. The aim of this study was to investigate the metabolite profile of the SARM ACP-105 (2-chloro-4-[(3-endo)-3-hydroxy-3-methyl-8-azabicyclo[3.2.1]oct-8-yl]-3-methylbenzonitrile) in order to find analytical targets for doping control. Oral administration of ACP-105 was performed in horses, where blood and urine samples were collect...
Moreira F, Carmo H, Guedes de Pinho P, Bastos ML.Despite the impressive innate physical abilities of horses, camels, greyhounds, or pigeons, doping agents might be administered to these animals to improve their performance. To control these illegal practices, anti-doping analytical methodologies have been developed. This review compiles the analytical methods that have been published for the detection of prohibited substances administered to animals involved in sports over 30 years. Relevant papers meeting the search criteria that discussed analytical methods aiming to detect and/or quantify doping substances in animal biological matrices pu...
D'Fonseca NMM, Gibson CME, Hummel I, van Doorn DA, Roelfsema E, Stout TAE, van den Broek J, de Ruijter-Villani M.Obesity has been associated with altered reproductive activity in mares, and may negatively affect fertility. To examine the influence of long-term high-energy (HE) feeding on fertility, Shetland pony mares were fed a diet containing 200% of net energy (NE) requirements during a three-year study. The incidence of hemorrhagic anovulatory follicles (HAF) and annual duration of cyclicity were compared to those in control mares receiving a maintenance diet. Day-7 embryos were flushed and transferred between donor and recipient mares from both groups; the resulting conceptuses were collected 21 day...
de Ruijter-Villani M, van Boxtel PR, Stout TA.Uterine-derived growth factors and cytokines play essential roles in regulating preimplantation conceptus development. In several species, fibroblast growth factor-2 (FGF2) promotes embryogenesis, trophoblast cell migration, and adhesion. This study investigated mRNA expression for FGF2, its receptors (FGFR1-4), the activating factor FGF binding protein (FGF-BP) in equine endometrium and trophectoderm during early pregnancy and the estrous cycle, and localized FGF2 protein in both endometrium and conceptus tissues. FGF2, FGFRs1-4, and FGFBP mRNAs were expressed in endometrium throughout the es...
Hinchcliff KW, Rush BR, Farris JW.To evaluate plasma epinephrine and norepinephrine concentrations and serum cortisol concentration in horses with colic and assess the relationship of these variables with clinical signs, routinely measured clinicopathologic variables, and outcome in affected horses. Methods: Prospective observational study. Methods: 35 horses with colic. Methods: Blood samples were collected within 30 minutes of arrival at the veterinary hospital from horses referred because of colic. Plasma and serum samples were analyzed for cortisol, epinephrine, norepinephrine, lactate, and electrolyte concentrations and a...
Morris DD, Moore JN, Crowe N.Over a 24-month period, serum tumor necrosis factor (TNF) activity was determined in 289 horses with colic attributable to gastrointestinal tract disease. Serum TNF activity was quantitated by use of a modified in vitro cytotoxicity bioassay, using WEHI 164 clone-13 murine fibrosarcoma cells. Causes for colic, determined by clinical and laboratory evaluation, exploratory celiotomy, or necropsy included: gastrointestinal tract rupture (GTR); ileal impaction; small intestinal strangulating obstruction (SIO); proximal enteritis (PE); transient small intestinal distention; large-colon displacement...
Cho HC, Hwang S, Kim EM, Park YJ, Shin SU, Jang DH, Chae JS, Choi KS. is an obligate intracellular zoonotic bacterium with a global distribution. This study was conducted to investigate the prevalence of in different animals and to assess the potential role of these species as reservoirs of infection and transmission to humans. A total of 592 blood samples (105 beef cattle, 61 dairy cattle, 110 Korean native goats, 83 Boer goats, and 233 horses) were collected in the Republic of Korea (ROK). The DNA was detected from blood samples using the transposon-like repetitive region () by PCR method. The results showed that 22.7% of the Korean-native goats, 16.4% of t...
Mack M, Kowalski E, Grahn R, Bras D, Penedo MCT, Bellone R.A unique eye color, called tiger-eye, segregates in the Puerto Rican Paso Fino (PRPF) horse breed and is characterized by a bright yellow, amber, or orange iris. Pedigree analysis identified a simple autosomal recessive mode of inheritance for this trait. A genome-wide association study (GWAS) with 24 individuals identified a locus on ECA 1 reaching genome-wide significance ( = 1.32 × 10). This ECA1 locus harbors the candidate gene, (), (), with known roles in pigmentation in humans, mice, and zebrafish. Humans with compound heterozygous mutations in have oculocutaneous albinism (OCA) type...
Gerlach T, Aurich JE.This review considers seasonal reproduction in male animals with emphasis on the stallion, ram and hamster. The pineal hormone melatonin is the common link between photoperiod and reproduction. An increase in the daily diurnal period of melatonin secretion is associated with a decrease in GnRH release in long-day breeders, but an increase in GnRH release in short-day breeders. Melatonin influences GnRH release within or close to the mediobasal hypothalamus in rams; whereas melatonin receptors have not been found in the hypothalamus of horses. Prolactin release is positively correlated with day...
Elia G, Lanave G, Lorusso E, Parisi A, Trotta A, Buono R, Martella V, Decaro N, Buonavoglia C.Equine hepacivirus is the closest homologue of hepatitis C virus. Limited data on the clinical features of this infection are available. We report the identification of a horse with high-titre viremia by equine hepacivirus. Over a 15-month follow-up, the clinical signs and the viremic status persisted, suggesting a chronic evolution.
van Duijkeren E, Wannet WJ, Heck ME, van Pelt W, Sloet van Oldruitenborgh-Oosterbaan MM, Smit JA, Houwers DJ.We studied 232 Salmonella strains from horses with salmonellosis in The Netherlands, isolated in the period from 1993 to 2000 in order to provide insight in the dynamics of sero-, phage types (pt) and antibiotic susceptibilities over time. The strains were tested for susceptibility to seven antimicrobial agents using the agar diffusion method. In addition, the isolates were sero typed and Salmonella enterica subspecies enterica Typhimurium and Enteritidis strains were further phage typed. S. Typhimurium strains of phage type 506 and 401 (both classified as DT 104 in the English phage typing sy...
Koterba AM, Kosch PC, Beech J, Whitlock T.To investigate the mechanism underlying the polyphasic airflow pattern of the equine species, we recorded airflow, tidal volum, rib cage and abdominal motion, and the sequence of activation of the diaphragm, intercostal, and abdominal muscles during quiet breathing in nine adult horses standing at rest. In addition, esophageal, abdominal, and transdiaphragmatic pressures were simultaneously recorded using balloon-tipped catheters. Analysis of tidal flow-volume loops showed that, unlike humans, the horse at rest breathes around, rather than from, the relaxed volume of the respiratory system (Vr...
Mellor PS.1. 903 horses were examined at 3 abattoirs in South East England. 10(22–7%) of the horses at the London Colney abattoir, 23(13–9%) of those at the Braintree abattoir, Essex, and 90(12–9%) of those at the Islington abattoir, London, were infected with O. cervicalis. All 105 horses examined in Southern Ireland were found to be negative.
2. The adult worms of O. cervicalis were found without exception, in the ligamentum nuchae of infected horses. The suspensory ligaments of the fetlock and flexor tendons were always negative.
3. The microfilariae of O. cervicalis concentrate along the...
Parry BW, Anderson GA, Gay CC.The individual merit of the use of 43 variables to assess the prognosis of equine colic cases was examined. The following variables revealed highly significant (P less than 0.001) differences between cases which survived and those which died: blood pressure; heart rate; oral mucosal capillary refill time; degree of mental depression; venous haemoglobin concentration, haematocrit, erythrocyte count, urea concentration and lactate concentration; peritoneal fluid lactate concentration; and haematocrit/plasma protein and serum protein concentration ratios. Thus, in general, variables which assesse...
Paillot R, Ellis SA, Daly JM, Audonnet JC, Minke JM, Davis-Poynter N, Hannant D, Kydd JH.Equine herpesvirus-1 (EHV-1) is a ubiquitous pathogen of horses, which continues to cause respiratory and neurological disease and abortion, despite the widespread use of vaccines. Cell mediated immunity (CMI) is thought to play a major role in protection against infection with EHV-1. The aim of this study was to characterise the virus-specific CMI response in ponies vaccinated with vP1014, a vaccinia-based construct (NYVAC) coding for the immediate early gene (gene 64) of EHV-1. This gene product is a CTL target protein for an equine MHC class I allele expressed on the A3 haplotype. EHV-prime...
Zarski LM, Giessler KS, Jacob SI, Weber PSD, McCauley AG, Lee Y, Soboll Hussey G.Equine herpesvirus-1 is the cause of respiratory disease, abortion, and equine herpesvirus myeloencephalopathy (EHM) in horses worldwide. EHM affects as many as 14% of infected horses and a cell-associated viremia is thought to be central for EHM pathogenesis. While EHM is infrequent in younger horses, up to 70% of aged horses develop EHM. The aging immune system likely contributes to EHM pathogenesis; however, little is known about the host factors associated with clinical EHM. Here, we used the "old mare model" to induce EHM following EHV-1 infection. Peripheral blood mononuclear cells (PBMC...
Cursino AE, Vilela APP, Franco-Luiz APM, de Oliveira JG, Nogueira MF, Júnior JPA, de Aguiar DM, Kroon EG.Equine infectious anemia (EIA) has a worldwide distribution, and is widespread in Brazil. The Brazilian Pantanal presents with high prevalence comprising equine performance and indirectly the livestock industry, since the horses are used for cattle management. Although EIA is routinely diagnosed by the agar gel immunodiffusion test (AGID), this serological assay has some limitations, so PCR-based detection methods have the potential to overcome these limitations and act as complementary tests to those currently used. Considering the limited number of equine infectious anemia virus (EIAV) seque...
Costa LR, Johnson JR, Baur ME, Beadle RE.To describe the seasonal pattern of clinical exacerbation of summer pasture-associated recurrent airway obstruction (SPA-RAO) in relation to climate and aeroallergens in horses. Methods: 19 horses with SPA-RAO and 10 nonaffected horses. Methods: Daily examinations were performed on all horses while they were kept on pasture for 3 years. Onset and progression of clinical exacerbation based on a clinical score of respiratory effort were evaluated in relation to changes in maximum temperature, minimum temperature, mean temperature, maximum dew-point temperature, minimum dew-point temperature, and...
Ogbourne CP.Observations have been made on the development and survival of the free-living stages in faeces deposited out of doors at different times of year, and on the migration of infective larvae to the surrounding herbage. Laboratory experiments were performed to assist in the interpretation of the field observations. Studies were made on the rate of development to the infective stage in faeces kept at different temperatures. The rates at which eggs and larvae of Strongylus vulgaris, S edentatus, S. equinus and Trichonema nassatum developed on faecal-agar cultures at different temperatures were compa...
Halpin K, Graham K, Durr PA.Hendra virus (HeV) is a high consequence zoonotic pathogen found in Australia. The HeV vaccine was developed for use in horses and provides a One Health solution to the prevention of human disease. By protecting horses from infection, the vaccine indirectly protects humans as well, as horses are the only known source of infection for humans. The sub-unit-based vaccine, containing recombinant HeV soluble G (sG) glycoprotein, was released by Pfizer Animal Health (now Zoetis) for use in Australia at the end of 2012. The purpose of this study was to collate post-vaccination serum neutralising anti...
Morotomi M, Yuki N, Kado Y, Kushiro A, Shimazaki T, Watanabe K, Yuyama T.Lactobacillus equi sp. nov. is described on the basis of 18 strains isolated as one of the predominant intestinal lactobacilli from horse faecal specimens. These 18 strains were isolated from 10 horses of 6 different farms out of 20 horses of 10 farms examined. They were gram-positive, facultatively anaerobic, catalase-negative, non-spore-forming, non-motile, lactic-acid-homofermentative rods. The DNA G+C content was 38.9+/-0.8 mol %. DNA-DNA hybridization failed to associate these strains closely with any of the validly described type strains used. Analysis of the 16S rRNA gene sequence of re...
Boyle AG, Rankin SC, D￮ L, Boston RC, Wheeler-Aceto H.Bacterial culture and polymerase chain reaction (PCR) assays for the detection of Streptococcus equi in nasopharyngeal washes (NPW) and guttural pouch lavage (GPL) samples have low sensitivity. In human diagnostics, processing of samples with flocked swabs has improved recovery rates of bacterial agents because of improved surface area and elution factors. Objective: For S. equi subsp. equi (S. equi) detection in NPW and GPL samples we hypothesized that: direct-PCR would be more reliable than flocked swab culture (FS culture); flocked swab PCR (FS-PCR) would be equivalent to direct-PCR; and FS...
Rogers CW, Firth EC, McIlwraith CW, Barneveld A, Goodship AE, Kawcak CE, Smith RK, van Weeren PR.No data exist on the intensity of exercise required or on possible harmful effects of increasing exercise in foals over the natural level when free at pasture. Objective: To investigate whether an increase in workload over free pasture exercise in the period from directly after birth to the start of training is tolerated by Thoroughbred (TB) foals without increasing injury rate or producing other undesired side effects. Methods: Thirty-three TB foals were allocated to one of 2 exercise groups directly after birth. One group (PASTEX) was raised on pasture and the other (CONDEX) kept under ident...
Zapf F, Schein E.The development of the piroplasm Babesia equi was studied by light microscopy in the gut and the haemolymph of three different Hyalomma species during and after the nymphs had engorged on parasitaemic horses. The stock of B. equi used was isolated from a horse imported from Turkmenistan (CIS) in 1991. The existence of gamogony was identified by the occurrence of gamonts and gametes in the gut contents of the nymphs at between 3 and 4 days after infestation of the nymphs, before the ticks dropped off the experimentally infected horses. Zygotes and kinetes were observed in the intestinal cells f...
Howerth EW, Mead DG, Mueller PO, Duncan L, Murphy MD, Stallknecht DE.Horses were inoculated with Vesicular stomatitis New Jersey and Indiana viruses by routes simulating contact and vector transmission. Clinical signs, lesions, antibody development, viral shedding and persistence, and viremia were monitored. Horses were infected with both viruses by all routes as confirmed by seroconversion. Salivation, primary lesions at inoculation sites, and secondary oral lesions were the most common clinical findings. Viral shedding was most often from the oral cavity, followed by the nasal cavity; titers were highest from oral cavity samples. Virus was rarely isolated fro...
Tomonaga M, Kumazaki K, Camus F, Nicod S, Pereira C, Matsuzawa T.Mammals have adapted to a variety of natural environments from underwater to aerial and these different adaptations have affected their specific perceptive and cognitive abilities. This study used a computer-controlled touchscreen system to examine the visual discrimination abilities of horses, particularly regarding size and shape, and compared the results with those from chimpanzee, human and dolphin studies. Horses were able to discriminate a difference of 14% in circle size but showed worse discrimination thresholds than chimpanzees and humans; these differences cannot be explained by visu...
Depuydt E, Broeckx SY, Van Hecke L, Chiers K, Van Brantegem L, van Schie H, Beerts C, Spaas JH, Pille F, Martens A. Tendon injuries are very common in horses and jeopardize the athletic performance, and due to the high risk of reinjury may lead to early retirement. The use of mesenchymal stem cells for the treatment of equine tendon disease is widely investigated because of their regenerative potential. The objective of this study is to investigate the safety and efficacy of equine allogeneic tenogenic primed mesenchymal stem cells (tpMSCs) for the management of tendinitis in horses. A core lesion was surgically induced in the superficial digital flexor tendon of both forelimbs of eight horses. After 7 da...
Crouch CF, Daly J, Henley W, Hannant D, Wilkins J, Francis MJ.In horses, natural infection confers long lasting protective immunity characterised by mucosal IgA and humoral IgGa and IgGb responses. In order to investigate the potential of locally administered vaccine to induce a protective IgA response, responses generated by vaccination with an immunostimulating complex (ISCOM)-based vaccine for equine influenza (EQUIP F) containing A/eq/Newmarket/77 (H7N7), A/eq/Borlänge/91 (H3N8) and A/eq/Kentucky/98 (H3N8) using a systemic prime/mucosal boost strategy were studied. Seven ponies in the vaccine group received EQUIP F vaccine intranasally 6 weeks after...
Peiró JR, Barnabé PA, Cadioli FA, Cunha FQ, Lima VM, Mendonça VH, Santana AE, Malheiros EB, Perri SH, Valadão CA.The clinical efficacy of IV infusion of lidocaine for treatment of equine endotoxemia has not been studied. Objective: Lidocaine infusion after exposure to lipopolysaccharide (LPS) will inhibit the inflammatory response and have inhibitory effects on the hemodynamic and cytokine responses to endotoxemia. Methods: Twelve horses. Methods: Two equal groups (n=6): saline (GI) and lidocaine (GII). In all animals, endotoxin (500 ng/kg body weight [BW]) was injected intraperitoneally over 5 minutes. Twenty minutes later, animals received a bolus of GI or GII (1.3 mg/kg BW) over 5 minutes, followed by...
Votion DM, Linden A, Delguste C, Amory H, Thiry E, Engels P, van Galen G, Navet R, Sluse F, Serteyn D, Saegerman C.Over the last decade, atypical myopathy (AM) in grazing horses has emerged in several European countries. An exploratory analysis was conducted to determine horse- and pasture-level indicators or factors associated with AM in Belgium. Belgian cases of AM confirmed by histology (n=57) were compared to their healthy co-grazing horses (n=77) and to pastured horses not involved with AM as controls (n=386). The pastures where confirmed cases were grazing (42 pastures; 38 sites; 44 incidences of AM) were compared with those of the controls (216 pastures; 96 sites; no incidence of AM). Statistically ...
Meiswinkel R.During the 1996 summer season (January-April) in South Africa an estimated 500 horses died of African horse sickness (AHS); 80% of deaths were due to AHS virus serotypes 2 and 4. Nearly all cases occurred in the northern, north-eastern and central parts of South Africa. This study reports the first attempt to verify the involvement of the biting midge Culicoides imicola in a field outbreak of AHS in southern Africa. In light-trap collections made at 47 sites over 12 weeks, C. imicola comprised 94.2% of 4.78 million Culicoides. Culicoides imicola was the most prevalent of 34 species captured an...
Dickey EJ, Long SN, Hunt RW.Hypoxic ischemic encephalopathy (HIE) is a condition that occurs in both human newborns and foals. The condition is the subject of extensive current research in human infants, but there have been no direct studies of HIE in foals, and hence, knowledge of the condition has been extrapolated from studies in humans and other animal models. The purpose of this review article is to highlight the most up-to-date and relevant research in the human field, and discuss how this potentially might have an impact in the management of foals with HIE.
