"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.
Ledbetter EC, Knickelbein KE, Irby NL, Schmidt C.To describe the clinical and in vivo confocal microscopy (IVCM) characteristics of horses with corneal stromal invasive squamous cell carcinoma (CSI-SCC). Methods: Retrospective study of 7 horses with histopathologically confirmed unilateral CSI-SCC. Methods: Horses with corneal CSI-SCC were examined by laser scanning IVCM. Signalment, clinical findings, and histopathology results were compared with IVCM findings. Results: Clinical ocular lesions in all horses included a heavily vascularized, opaque, gray or tan, anterior or midstromal opacity invading the cornea from the limbus. The corneal ...
Çortu A, Çınar H.Rectal examination is routine in equine reproduction but may trigger acute stress affecting welfare and safety. Intraocular pressure (IOP) responds rapidly to autonomic changes and may capture short-lived stress responses. Objective: To evaluate whether rectal examination acutely affects IOP and behavioral responses in mares, and whether reactions differ by reproductive status. Methods: Twenty Rahvan mares (10 pregnant, 30-40 days' gestation; 10 non-pregnant; 4-7 years) underwent transrectal examination without sedation. IOP was measured bilaterally at six time points: 2 min pre-exam (T1), dur...
Hendrikx AL, Vendrig JC, Gehring R, van den Boom R, van Alphen J, Vernooij JCM, Teske E, Roelfsema E.To determine the effect of repeated IV administration of dexamethasone (0.06 mg/kg, q 24 h, twice) on WBC parameters in healthy adult horses. Unassigned: This prospective, longitudinal study was conducted from October 7 through November 5, 2024. Five warmblood mares received an IV dexamethasone sodium phosphate injection (DMI) at 0 and 24 hours and an IV injection with 0.9% sodium chloride solution at 48 and 72 hours. Blood samples were collected at 0, 6, 12, 24, 30, 36, 48, 72, 96, and 168 hours, and WBC parameters were evaluated using linear mixed-effects models. Unassigned: Leukocyte count,...
Armangau M, Lurier T, Josson A.Offspring Sex Ratio (OSR) at birth in mammals is generally assumed to follow a 1:1 male-to-female distribution, yet deviations in OSR have been observed and may be influenced by maternal and paternal factors. In this study we have focused on the effect of paternal factors (stallion age and breed) and breeding methods on the OSR. Using a retrospective dataset of 251,783 foal births recorded in France between 2015 and 2024, we applied generalized linear mixed models to evaluate the effects of these variables on the likelihood of producing a female foal. Stallion identity was included as a random...
Watson W, MacKay JRD, Dwyer C.This study aims to improve the welfare and management of recreational horses by identifying how different management styles affect horse health and behaviour. We examined the management styles of recreational horse owners in the UK and Ireland, focusing on social interaction (friends), access to suitable forage (forage), and unrestricted movement (freedom). We collected 1,501 survey responses, distributed via social media, and summarised the characteristics and management choices of the respondents. Using the Divisive ANAlysis cluster package in R, three distinct management styles were identif...
Andrade AC, Fonseca SMC, Silva Filho GB, Melo ET, Santos JRP, Frota MLSL, Duarte JMBS, Evêncio-Neto J, Brito LB, Lima TS, Wicpolt NS, Riet-Correa F....We report an outbreak of Crotalaria juncea intoxication in horses exhibiting progressive weight loss and respiratory distress in northeastern Brazil. Necropsy revealed firm, non-collapsed lungs with extensive interstitial fibrosis, bronchiolar epithelial hyperplasia with club cells proliferation, and marked pulmonary arterial remodeling. Hepatic lesions consisted primarily of centrilobular necrosis, probably resulting from hypoxic injury related to anemia and prolonged agonic death. Pasture inspection identified significant invasion by shrubs of C. juncea in various phenological stages.
Granello ME, Young JM, Cleff DB, Banks EBM, Trumble TN.To describe characteristics of postoperative peritoneal fluid following exploratory laparotomy for naturally-occurring gastrointestinal lesions in horses. Methods: Prospective, observational cohort study. Methods: A total of 26 client-owned horses that underwent exploratory laparotomy for naturally-occurring gastrointestinal lesions. Methods: Abdominocentesis was performed pre- or intraoperatively, and at three time points postoperatively (24, 72, and 168 h). Peritoneal lactate, total protein (TP), total nucleated cell count (TNCC), cytology, and systemic lactate were performed at each time ...
Gartland KL, Leśniak K, Twigg-Flesner A.Scientific interest in relation to Fragile Foal Syndrome (FFS) has proliferated in the last decade, but before this, many clinical cases were attributed to other similarly presenting equine neonatal disorders. It was thought that FFS-affected foals were mainly miscarried throughout gestation, but recent study results suggest that often, foals are born alive and die shortly after birth. FFS is proposed to have originated as long ago as the Godolphin Arabian, but the definite derivation of the mutant allele is unconfirmed. The discovery that FFS is present in 11-30% of Warmbloods and 2-3% of Tho...
DeBel NA, Yalavarthi G, Johnson JR, Simoneau AT, Sweeney B, Stearns G, Saliceti A, Rutstein H, Amalaradjou MA, Govoni KE, McBride ZG, Moore TE....Strongyles are nematode parasites that affect the large intestine and cecum of the horse, with symptoms ranging from poor hair coat to colic. This can influence gut health, nutrient absorption, and overall body condition. Objective: Determine the effects of parasitic load, breed, age, housing, and season on skin and hair coat conditions. We hypothesized that horses with low fecal egg counts would have better hair and skin coat condition compared with those with high fecal egg counts. Methods: A total of forty-five Morgan and 11 Thoroughbred horses were included in this study. We tested the eff...
Dundjerovic I, Sneddon LU.Animal welfare concerns both the physical and mental wellbeing of animals so the assessment of animals kept in captivity, for example zoos, is important and necessary both legally and ethically. Good welfare is especially vital when breeding endangered species as stress impairs reproductive investment. As zoos often have high numbers of visitors, it is important to know if humans and the associated noise might influence the animals' welfare. The aim of this study was to investigate whether the presence of visitors and activities offered to the visitors caused a stress response in horses housed...
Nixon W, Buckley P, Butler R.There is a lack of information on horse parasite management practices currently used by individual horse owners in Australia. A voluntary, anonymous online survey was developed for and distributed by Pony Club Australia to its members seeking information on horse population; housing; paddock, manure and parasite management; and owner attitudes. From a total of 98 completed responses, 95/98 of participants indicated their horses spent time in paddocks, 91/98 administered anthelmintics, 42/98 guessed their horse's body weight for dosing, 78/98 recalled the dewormer brand or active ingredient las...
Valera M, Encina A, Sánchez-Guerrero MJ, Rodríguez-Sainz de Los Terreros A, Bartolomé E.Behavioral and emotional reactivity assessment in sport horses is essential for optimizing their management and sports performance, particularly in equestrian disciplines such as Dressage. This study investigates, in Pura Raza Española (PRE) horses, the association between facial hair whorl (FHW) patterns, behavioral traits, and physiological stress responses using ocular temperature (OT) assessed with infrared thermography as, an objective, non-invasive physiological stress indicator. Unassigned: A total of 98 male PRE horses, aged 4-6 years old and all gray coated, were evaluated during the...
O'Reilly K, Aldworth-Yang S, Catalano DN.There are many different concentrate feeders available to horse owners, but little data exists on feeder effect of equine intake rate. Rapid consumption ("bolting") is associated with issues such as esophageal obstruction. Objective: The objective of this study was to evaluate three common concentrate feeders on intake rate. We hypothesized horses would have the slowest intake rate when fed from the trough. Methods: Four geldings were fed 0.454 kg of concentrate from a pan on the ground (P), shallow trough (T), or hanging feeder (H). Horses were randomly assigned a first feeder and then rotate...
Byrne J, Guedes AG, Hickey C, Hatschbach E, Walters B, Rendahl A, Tearney C.To evaluate the utility of the dynamic indices, systolic pressure variation (SPV%), pulse pressure variation (PPV%) and plethysmographic variability index (PVI%) during induced hypovolemia, and to determine their correlation with cardiac output (CO) in anesthetized horses. Methods: Prospective experimental study. Methods: A group of eight healthy adult research horses. Methods: After sedation with intravenous (IV) xylazine, anesthesia was induced with IV ketamine and diazepam and maintained with constant-dose isoflurane delivered in 100% oxygen. Horses were positioned in dorsal recumbency, par...
Strugava L, Serighelli-Júnior G, Stadler LM, Flores LADS, Minozzo GA, Dornbusch LPTC, Moreno JCD, Dornbusch PT.Rectal amputation is a surgical approach indicated for the management of severe rectal lacerations or extensive rectal prolapse when transmural compromise or primary repair is unfeasible. These conditions, although uncommon, present substantial challenges in equine practice due to the anatomical complexity of the pelvic region and the potential for life-threatening complications if not adequately addressed. This study aimed to describe and standardize a reproducible surgical technique for rectal amputation in horse cadavers. Six equine cadavers (mean body mass, 441.83± 66.84 kg) were position...
Campos Schweitzer A, Mespoulhes-Rivière C, Perkins JD, Ducharme NG, Piercy RJ, Lynch N, Rossignol F.To evaluate functional and histopathologic outcomes of standing selective laryngeal reinnervation using the spinal accessory nerve (SAN) in horses with experimentally induced recurrent laryngeal neuropathy (RLN). Methods: Five Thoroughbred mares. Methods: Prospective cohort study. Methods: The horses underwent left recurrent laryngeal neurectomy followed 8 weeks later by selective laryngeal reinnervation using the SAN. Follow-up evaluations at 4.5, 6, 8, and 12 months included treadmill exercising endoscopy, ultrasonography of intrinsic laryngeal muscles, and percutaneous electrical stimul...
Mählmann K, Lischer CJ.This technical note describes the use of a manual graphic roadmap (MGR) to assist fluoroscopic guidance during transarterial coil embolization (TACE) for guttural pouch (GP) arterial hemorrhage. Horses underwent MGR-assisted TACE at the Equine Clinic, Free University of Berlin, between 2012 and 2024. Surgery was performed under general anesthesia with fluoroscopic guidance. Following the initial angiogram, a transparent foil was secured to the fluoroscopy monitor, and an assistant traced the vascular anatomy with a waterproof marker to create the MGR, which then served as a guide for catheter ...
Mukai K, Takahashi Y, Ebisuda Y, Sugiyama F, Yoshida T, Miyata H.This study tested the hypothesis that 6 weeks of high-intensity interval training (HIIT) would induce greater physiological adaptations than moderate-intensity continuous training (MICT) in Thoroughbred horses. Seven untrained horses completed two distance-matched treadmill training protocols (three sessions per week) in a randomized crossover design, separated by a three-month washout: MICT (6 min at 70% ) and HIIT (6 × [30 s at 100% with 30 s at 30% ]). Incremental exercise tests were conducted at weeks 0, 3, and 6 to assess exercise performance and physiological responses. M...
Zimmerman-Cameron SR, Colbath AC, Caruso MA, Hoffman RM, Logan AA.Navicular syndrome is characterized by palmar foot pain and is a common cause of lameness in horses. Palmar digital neurectomy (nerving) removes sensation to the heel region of the hoof and may serve as a treatment for navicular-afflicted horses, while analgesia (blocking) results in temporary loss of sensation. Objective: The purpose of this pilot study was to examine the effect of loss of sensation in the heel on the forelimb area and force while tracking on soft and hard ground at the walk and trot. Methods: Three horses that scored a 0 or 1 on the AAEP lameness scale were fitted to Tekscan...
Häussling MPP, Steinberg T, Büttner K, Hannig C, Hannig M, Lemke L, Zierau O, Staszyk C.Destructive lesions of the peripheral and infundibular cementum are increasingly recognized in equine dentistry. While similarities to human caries have been noted, current evidence does not conclusively support this classification. This study aims to assess the prevalence, distribution, and potential risk factors associated with these lesions in a defined horse population. Unassigned: A total of 114 horses from northern Germany underwent standardized oral examination between 2021 and 2023. Clinical data on peripheral and infundibular lesions, diastemata, and influencing factors such as age an...
Cerullo A, Scilimati N, Di Nicola MR, Colla L, Mazza S, Bertoletti A, Nannarone S, Gialletti R.Left dorsal displacement of the large colon (LDDLC) is a common cause of colic in horses and it is frequently associated with recurrent episodes, with significant implications for horse management, athletic performance, and owner satisfaction. Laparoscopic nephrosplenic space (NSS) ablation is a preventive surgical technique aimed at reducing recurrence in horses with a history of medically or surgically treated LDDLC. This retrospective study evaluated 48 horses that underwent laparoscopic NSS ablation in two Italian Veterinary Teaching Hospitals between 2016 and 2024. Short-term outcomes, in...
Amaral A, Cerveira-Pinto M, Santos C, Kordowitzki P, Skarzynski D, Ferreira-Dias G, Szóstek-Mioduchowska A.Transforming growth factor (TGF)-β1 is a pro-fibrotic cytokine that affects extracellular matrix (ECM) deposition and fibroblast activity. 17β-Estradiol (E), the dominant ovarian steroid during the follicular phase (FLP) of the estrous cycle, can also influence ECM remodeling and fibrosis, through prostaglandin (PG) synthesis. PGs have opposing roles in fibrosis, with PGE₂ showing anti-fibrotic effects and PGF₂α promoting fibrosis. Equine endometrosis, whose main pathological feature is fibrosis, is marked by chronic inflammation and ECM accumulation, and may involve mediators like TGF-...
Kamr A, Fortin-Trahan R, Arroyo LG, Hostnik LD, Gomez DE, Toribio RE.Hypocalcemia is frequent in horses with colitis. Information on serum parathyroid hormone (PTH) concentrations and its association with bone turnover biomarkers in horses with colitis is lacking. We aimed to determine the association between serum bone resorption biomarkers (C-terminal telopeptide of type I collagen [CTX-I]) and bone formation (osteocalcin [OCN]) with blood PTH, total calcium (tCa), ionized calcium (iCa), phosphorus (Pi), and total magnesium (tMg) concentrations, and mortality in horses with acute colitis. A total of 163 horses were divided into colitis (n = 127) and healt...
Acevedo-Jiménez GE, Morales-González C, Akbarin MM, Rodríguez-Murillo C, González-Fernández VD, Avila-De la Vega LM, García-Flores MM....Equine infectious anemia virus (EIAV) is a globally significant equine pathogen, and its control relies on effective serological surveillance. The agar gel immunodiffusion (AGID) test, the WOAH-prescribed method, has limitations in sensitivity. This study developed and validated an indirect ELISA using a synthetic peptide derived from a conserved region of the EIAV gp90 surface glycoprotein. The assay was evaluated using 773 horse sera from the Metropolitan Zone of the Valley of Mexico and compared to the AGID test. The gp90-EIAV ELISA demonstrated a sensitivity of 85.3 % and a specificity o...
Bramall LM, Hinnigan GJ, Wattam AD, Owen KR.This case report describes the successful hemithyroidectomy of the largest equine solid follicular adenoma described in the veterinary literature to date. A 19-year-old thoroughbred mare was referred to Oakhill Veterinary Centre for the surgical removal of a large, left-sided thyroid gland measuring 26cm in diameter. Pre-operative considerations, the hemithyroidectomy surgical technique as well as the intra- and post-operative complications encountered, are discussed. Following surgery the horse had no long-term complications and continues to thrive four and a half years post-operatively.
Folgmann MS, Stock KF, Feige K, Delling U.Current studies on the health status of young German Warmblood stallions are lacking. Objective: To evaluate the prevalence of radiographic findings at licensing examinations of Warmblood candidate stallions and quantify the environmental influences on the distribution of recorded findings. Methods: In this retrospective observational study, records of 1693 radiographic examinations performed on 1678 German Warmblood stallions presented for licensing in 2018-2020 were reviewed. Data were provided by all German Warmblood horse-breeding associations and their official veterinarians. The collecti...
Donato GG, Necchi D, Gionechetti F, Ala U, Nebbia P, Robino P, Stella MC, Vandaele H, Pallavicini A, Nervo T.In the past, bacteria detected in the mare's uterus were generally interpreted as a sign of endometritis, since the uterus was considered a sterile environment. This assumption has been challenged by the introduction of culture-independent molecular techniques, particularly 16S rRNA amplicon sequencing, which have demonstrated that healthy mares harbor an endometrial microbiota. The aim of this study was to characterize the endometrial microbiota of healthy mares and to determine whether microbial composition differs between estrus and diestrus. Endometrial samples were collected from eleven h...
Kremer H, Bartling B.The nasal vestibule of numerous horses is pigmented. In the ventral part of the nasal vestibule, this pigmentation is often disturbed resulting in a clearly depigmented area. As nasal discharge passes this area, our study aimed at the practical quantification of the depigmented area in the nasal vestibule of horses and the analysis of its relation to nasal discharge and other parameters.This study included 74 horses (59 warmblood horses, 15 ponies) with pigmented nasal vestibule. When a depigmentation was found to be present in the ventral part, this area was photographed and quantified by use...
Selvey LA, Wells RM, McCormack JG, Ansford AJ, Murray K, Rogers RJ, Lavercombe PS, Selleck P, Sheridan JW.To describe the clinical and epidemiological features of an outbreak of a viral infection affecting humans and horses. Methods: Stables in Hendra, a suburb of Brisbane. Methods: Affected horses and humans, and at-risk human contacts. Results: A pregnant mare died two days after arrival from a paddock elsewhere in Brisbane. Eight to 11 days later, illness (depression, anorexia, fever, dyspnoea, ataxia, tachycardia, tachypnoea and nasal discharge) was reported among 17 other horses from the same or an adjoining stable. Fourteen horses died or were put down. Five and six days after the index mare...
Ching PK, de los Reyes VC, Sucaldito MN, Tayag E, Columna-Vingno AB, Malbas FF, Bolo GC, Sejvar JJ, Eagles D, Playford G, Dueger E, Kaku Y....During 2014, henipavirus infection caused severe illness among humans and horses in southern Philippines; fatality rates among humans were high. Horse-to-human and human-to-human transmission occurred. The most likely source of horse infection was fruit bats. Ongoing surveillance is needed for rapid diagnosis, risk factor investigation, control measure implementation, and further virus characterization.
Pawelek KA, Huynh GT, Quinlivan M, Cullinane A, Rong L, Perelson AS.Influenza virus infection remains a public health problem worldwide. The mechanisms underlying viral control during an uncomplicated influenza virus infection are not fully understood. Here, we developed a mathematical model including both innate and adaptive immune responses to study the within-host dynamics of equine influenza virus infection in horses. By comparing modeling predictions with both interferon and viral kinetic data, we examined the relative roles of target cell availability, and innate and adaptive immune responses in controlling the virus. Our results show that the rapid and ...
McIlwraith CW, Frisbie DD, Kawcak CE.Osteoarthritis (OA) is an important cause of pain, disability and economic loss in humans, and is similarly important in the horse. Recent knowledge on post-traumatic OA has suggested opportunities for early intervention, but it is difficult to identify the appropriate time of these interventions. The horse provides two useful mechanisms to answer these questions: 1) extensive experience with clinical OA in horses; and 2) use of a consistently predictable model of OA that can help study early pathobiological events, define targets for therapeutic intervention and then test these putative thera...
Kohn RA, Dinneen MM, Russek-Cohen E.The objectives of this study were to evaluate the potential for using blood urea N concentration to predict urinary N excretion rate, and to develop a mathematical model to estimate important variables of N utilization for several different species of farm animals and for rats. Treatment means (n = 251) from 41 research publications were used to develop mathematical relationships. There was a strong linear relationship between blood urea N concentration (mg/100 mL) and rate of N excretion (g x d(-1) x kg BW(-1)) for all animal species investigated. The N clearance rate of the kidney (L of bloo...
Weaver SC, Salas R, Rico-Hesse R, Ludwig GV, Oberste MS, Boshell J, Tesh RB.Venezuelan equine encephalomyelitis (VEE) virus has caused periodic epidemics among human beings and equines in Latin America from the 1920s to the early 1970s. The first major outbreak since 1973 occurred in Venezuela and Colombia during 1995, and involved an estimated 75,000 to 100,000 people. We report an epidemiological and virological investigation of this epidemic. Methods: Virus isolates were made in cell culture from human serum, human throat swabs, and brain tissue from aborted and stillborn human fetuses, as well as from horse brain tissue and pooled mosquito collections. Human sera ...
McCarrel TM, Minas T, Fortier LA.Numerous methods are available for platelet-rich plasma (PRP) generation, but evidence defining the optimum composition is lacking. We hypothesized that leukocyte-reduced PRP would result in lower inflammatory cytokine expression compared with concentrated-leukocyte PRP and that maintaining the platelet:white blood cell (WBC) ratio would compensate for the effect of increased WBC concentration. Methods: Blood and flexor digitorum superficialis tendons were collected from young adult horses. Three PRP groups were generated with the same platelet concentration but different WBC concentrations: i...
Science (New York, N.Y.)March 7, 2009
Volume 323, Issue 5919 1332-1335 doi: 10.1126/science.1168594
Outram AK, Stear NA, Bendrey R, Olsen S, Kasparov A, Zaibert V, Thorpe N, Evershed RP.Horse domestication revolutionized transport, communications, and warfare in prehistory, yet the identification of early domestication processes has been problematic. Here, we present three independent lines of evidence demonstrating domestication in the Eneolithic Botai Culture of Kazakhstan, dating to about 3500 B.C.E. Metrical analysis of horse metacarpals shows that Botai horses resemble Bronze Age domestic horses rather than Paleolithic wild horses from the same region. Pathological characteristics indicate that some Botai horses were bridled, perhaps ridden. Organic residue analysis, usi...
Rosengren Pielberg G, Golovko A, Sundström E, Curik I, Lennartsson J, Seltenhammer MH, Druml T, Binns M, Fitzsimmons C, Lindgren G, Sandberg K....In horses, graying with age is an autosomal dominant trait associated with a high incidence of melanoma and vitiligo-like depigmentation. Here we show that the Gray phenotype is caused by a 4.6-kb duplication in intron 6 of STX17 (syntaxin-17) that constitutes a cis-acting regulatory mutation. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from Gray horses. Gray horses carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gra...
Marasas WF, Kellerman TS, Gelderblom WC, Coetzer JA, Thiel PG, van der Lugt JJ.Each of two horses was dosed by stomach tube with culture material on maize of Fusarium moniliforme MRC 826. One horse developed severe hepatosis and mild oedema of the brain after 6 doses of 2.5 g of culture material/kg body mass/day in 7 days. The second horse, in a similar experiment but at a dosage rate of 1.25 g/kg/day, developed mild hepatosis and moderate oedema of the brain. In both animals the brain oedema was particularly noticeable in the medulla oblongata. The mycotoxin fumonisin B1 was extracted and purified from the culture material of F. moniliforme MRC, 826 which contained appr...
Kalbfleisch TS, Rice ES, DePriest MS, Walenz BP, Hestand MS, Vermeesch JR, O Connell BL, Fiddes IT, Vershinina AO, Saremi NF, Petersen JL, Finno CJ....Recent advances in genomic sequencing technology and computational assembly methods have allowed scientists to improve reference genome assemblies in terms of contiguity and composition. EquCab2, a reference genome for the domestic horse, was released in 2007. Although of equal or better quality compared to other first-generation Sanger assemblies, it had many of the shortcomings common to them. In 2014, the equine genomics research community began a project to improve the reference sequence for the horse, building upon the solid foundation of EquCab2 and incorporating new short-read data, lon...
Chaucheyras-Durand F, Durand H.The use of probiotics for farm animals has increased considerably over the last 15 years. Probiotics are defined as live microorganisms which can confer a health benefit for the host when administered in appropriate and regular quantities. Once ingested, the probiotic microorganisms can modulate the balance and activities of the gastrointestinal microbiota, whose role is fundamental to gut homeostasis. It has been demonstrated that numerous factors, such as dietary and management constraints, can strongly affect the structure and activities of the gut microbial communities, leading to impaired...
Gaastra W, Lipman LJ, De Cock AW, Exel TK, Pegge RB, Scheurwater J, Vilela R, Mendoza L.Pythium insidiosum is an oomycete pathogenic in mammals. The infection occurs mainly in tropical and subtropical areas, particularly in horses, dogs and humans. Infection is acquired through small wounds via contact with water that contains motile zoospores or other propagules (zoospores or hyphae). The disease, though described as emerging has in fact already been described since 1884. Depending on the site of entry, infection can lead to different forms of pythiosis i.e. a cutaneous, vascular, ocular, gastrointestinal and a systemic form, which is rarely seen. The infection is not contagious...
Makvandi-Nejad S, Hoffman GE, Allen JJ, Chu E, Gu E, Chandler AM, Loredo AI, Bellone RR, Mezey JG, Brooks SA, Sutter NB.Horse body size varies greatly due to intense selection within each breed. American Miniatures are less than one meter tall at the withers while Shires and Percherons can exceed two meters. The genetic basis for this variation is not known. We hypothesize that the breed population structure of the horse should simplify efforts to identify genes controlling size. In support of this, here we show with genome-wide association scans (GWAS) that genetic variation at just four loci can explain the great majority of horse size variation. Unlike humans, which are naturally reproducing and possess many...
Drexler JF, Corman VM, Müller MA, Lukashev AN, Gmyl A, Coutard B, Adam A, Ritz D, Leijten LM, van Riel D, Kallies R, Klose SM, Gloza-Rausch F....Hepatitis C virus (HCV) is among the most relevant causes of liver cirrhosis and hepatocellular carcinoma. Research is complicated by a lack of accessible small animal models. The systematic investigation of viruses of small mammals could guide efforts to establish such models, while providing insight into viral evolutionary biology. We have assembled the so-far largest collection of small-mammal samples from around the world, qualified to be screened for bloodborne viruses, including sera and organs from 4,770 rodents (41 species); and sera from 2,939 bats (51 species). Three highly divergent...
Achilli A, Olivieri A, Soares P, Lancioni H, Hooshiar Kashani B, Perego UA, Nergadze SG, Carossa V, Santagostino M, Capomaccio S, Felicetti M....Archaeological and genetic evidence concerning the time and mode of wild horse (Equus ferus) domestication is still debated. High levels of genetic diversity in horse mtDNA have been detected when analyzing the control region; recurrent mutations, however, tend to blur the structure of the phylogenetic tree. Here, we brought the horse mtDNA phylogeny to the highest level of molecular resolution by analyzing 83 mitochondrial genomes from modern horses across Asia, Europe, the Middle East, and the Americas. Our data reveal 18 major haplogroups (A-R) with radiation times that are mostly confined ...
Petersen JL, Mickelson JR, Cothran EG, Andersson LS, Axelsson J, Bailey E, Bannasch D, Binns MM, Borges AS, Brama P, da Câmara Machado A, Distl O....Horses were domesticated from the Eurasian steppes 5,000-6,000 years ago. Since then, the use of horses for transportation, warfare, and agriculture, as well as selection for desired traits and fitness, has resulted in diverse populations distributed across the world, many of which have become or are in the process of becoming formally organized into closed, breeding populations (breeds). This report describes the use of a genome-wide set of autosomal SNPs and 814 horses from 36 breeds to provide the first detailed description of equine breed diversity. F(ST) calculations, parsimony, and dista...
Frisbie DD, Ghivizzani SC, Robbins PD, Evans CH, McIlwraith CW.Osteoarthritis in horses and in humans is a significant social and economic problem and continued research and improvements in therapy are needed. Because horses have naturally occurring osteoarthritis, which is similar to that of humans, the horse was chosen as a species with which to investigate gene transfer as a potential therapeutic modality for the clinical treatment of osteoarthritis. Using an established model of equine osteoarthritis that mimics clinical osteoarthritis, the therapeutic effects resulting from intra-articular overexpression of the equine interleukin-1 receptor antagonis...
Saenz RA, Quinlivan M, Elton D, Macrae S, Blunden AS, Mumford JA, Daly JM, Digard P, Cullinane A, Grenfell BT, McCauley JW, Wood JL, Gog JR.A key question in pandemic influenza is the relative roles of innate immunity and target cell depletion in limiting primary infection and modulating pathology. Here, we model these interactions using detailed data from equine influenza virus infection, combining viral and immune (type I interferon) kinetics with estimates of cell depletion. The resulting dynamics indicate a powerful role for innate immunity in controlling the rapid peak in virus shedding. As a corollary, cells are much less depleted than suggested by a model of human influenza based only on virus-shedding data. We then explore...
McCue ME, Bannasch DL, Petersen JL, Gurr J, Bailey E, Binns MM, Distl O, Guérin G, Hasegawa T, Hill EW, Leeb T, Lindgren G, Penedo MC, Røed KH....An equine SNP genotyping array was developed and evaluated on a panel of samples representing 14 domestic horse breeds and 18 evolutionarily related species. More than 54,000 polymorphic SNPs provided an average inter-SNP spacing of ∼43 kb. The mean minor allele frequency across domestic horse breeds was 0.23, and the number of polymorphic SNPs within breeds ranged from 43,287 to 52,085. Genome-wide linkage disequilibrium (LD) in most breeds declined rapidly over the first 50-100 kb and reached background levels within 1-2 Mb. The extent of LD and the level of inbreeding were highest in the ...
Yu L, Wei Y, Sun HX, Mahdi AK, Pinzon Arteaga CA, Sakurai M, Schmitz DA, Zheng C, Ballard ED, Li J, Tanaka N, Kohara A, Okamura D, Mutto AA, Gu Y....Dynamic pluripotent stem cell (PSC) states are in vitro adaptations of pluripotency continuum in vivo. Previous studies have generated a number of PSCs with distinct properties. To date, however, no known PSCs have demonstrated dual competency for chimera formation and direct responsiveness to primordial germ cell (PGC) specification, a unique functional feature of formative pluripotency. Here, by modulating fibroblast growth factor (FGF), transforming growth factor β (TGF-β), and WNT pathways, we derived PSCs from mice, horses, and humans (designated as XPSCs) that are permissive for dire...
Science (New York, N.Y.)February 13, 2001
Volume 291, Issue 5503 474-477 doi: 10.1126/science.291.5503.474
Vilà C, Leonard JA, Gotherstrom A, Marklund S, Sandberg K, Liden K, Wayne RK, Ellegren H.Domestication entails control of wild species and is generally regarded as a complex process confined to a restricted area and culture. Previous DNA sequence analyses of several domestic species have suggested only a limited number of origination events. We analyzed mitochondrial DNA (mtDNA) control region sequences of 191 domestic horses and found a high diversity of matrilines. Sequence analysis of equids from archaeological sites and late Pleistocene deposits showed that this diversity was not due to an accelerated mutation rate or an ancient domestication event. Consequently, high mtDNA se...
Lunn DP, Davis-Poynter N, Flaminio MJ, Horohov DW, Osterrieder K, Pusterla N, Townsend HG.Equine herpesvirus-1 is a highly prevalent and frequently pathogenic infection of equids. The most serious clinical consequences of infection are abortion and equine herpesvirus myeloencephalopathy (EHM). In recent years, there has been an apparent increase in the incidence of EHM in North America, with serious consequences for horses and the horse industry. This consensus statement draws together current knowledge in the areas of pathogenesis, strain variation, epidemiology, diagnostic testing, vaccination, outbreak prevention and control, and treatment.
Fortier LA, Mohammed HO, Lust G, Nixon AJ.Composites of chondrocytes and polymerised fibrin were supplemented with insulin-like growth factor-I (IGF-I) during the arthroscopic repair of full-thickness cartilage defects in a model of extensive loss of cartilage in horses. Repairs facilitated with IGF-I and chondrocyte-fibrin composites, or control defects treated with chondrocyte-fibrin composites alone, were compared before death by the clinical appearance and repeated analysis of synovial fluid, and at termination eight months after surgery by tissue morphology, collagen typing, and biochemical assays. The structure of cartilage was ...
O'Sullivan JD, Allworth AM, Paterson DL, Snow TM, Boots R, Gleeson LJ, Gould AR, Hyatt AD, Bradfield J.In September, 1994, an outbreak of severe respiratory disease affected 18 horses, their trainer, and a stablehand in Queensland, Australia. Fourteen horses and one human being died. A novel virus was isolated from those affected and named equine morbillivirus (EMV). We report a case of encephalitis caused by this virus. Results: A 35-year-old man from Queensland had a brief aseptic meningitic illness in August, 1994, shortly after caring for two horses that died from EMV infection and then assisting at their necropsies. He then suffered severe encephalitis 13 months later, characterised by unc...
Proops L, McComb K, Reby D.Individual recognition is considered a complex process and, although it is believed to be widespread across animal taxa, the cognitive mechanisms underlying this ability are poorly understood. An essential feature of individual recognition in humans is that it is cross-modal, allowing the matching of current sensory cues to identity with stored information about that specific individual from other modalities. Here, we use a cross-modal expectancy violation paradigm to provide a clear and systematic demonstration of cross-modal individual recognition in a nonhuman animal: the domestic horse. Su...
