Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Dantas FTDR, Canisso IF, Feijó LS, de Vasconcelos PMF, Campos ML, Ulanov AV, Li Z, Pizzi GLBL, Nogueira CEW, Curcio BR.Doxycycline is widely used in equine medicine, yet data on its pharmacokinetics and safety during late gestation are scarce. We investigated the pharmacokinetics, fetoplacental diffusion, and safety of compounded oral doxycycline in late-term pregnant mares. In the first experiment, six mares at 300 days of gestation received a single oral dose (10 mg/kg), and plasma concentrations were measured using LC-MS/MS. Pharmacokinetic analysis using non-compartmental and compartmental models showed rapid absorption, with a mean Cmax of about 6000 ng/mL reached within 0.8 h and a terminal half-life ...
James C, Sheahan J, Arthur P.Thoroughbred race performance is influenced by genetics, training, recovery, and management, but decisions about race readiness are often subjective and lack validated physiological markers. This study evaluated thiol-oxidised albumin, a blood-based indicator of oxidative stress, as a potential biomarker of pre-race fitness in Australian Thoroughbreds. Seventy-five clinically healthy racehorses from seven stables were monitored across 216 competitive events (150 races, 66 trials). Blood samples were collected from the jugular at baseline, 48 h pre-race, and for each day up to 8 days post-race ...
Malekipour F, Whitton RC, Muir P, Lee PV.Stress fractures are common in racehorses, with the metacarpophalangeal (MCP) joint being the most frequently affected site as it is subjected to high-magnitude and high-rate cyclic loads during training and racing. These loads lead to repeated compressive stresses, resulting in subchondral bone (SCB) sclerosis, fatigue microcracks, and matrix damage that can progress to parasagittal fractures or palmar osteochondral disease (POD). The present study developed joint-specific 3D FE models and slice-based FE models using standing CT images for three trained racehorses, each presenting distinct SC...
Harpke M, Brangsch H, Melzer F.In Germany, Contagious Equine Metritis (CEM) is a persistent problem in equine populations. The often subclinical nature of the disease, which is caused by the bacterium Taylorella equigenitalis, poses a problem for the breeding industry. However, there is a lack of knowledge about the genomic diversity of the pathogen in Germany, as studies on the genome level are lacking. Thus, in this study we sequenced 63 T. equigenitalis isolates from a strain collection and contemporary clinical isolates from before 2007-2024. Most of these isolates came from Icelandic horses in southern Germany. Based...
Gao W, Liu M, Nurdaly K, Caidan D, Sun Y, Duan J, Zhao J, Gong X, Zhou J, Zhang Y, Chen Q.Equine bacterial abortion presents substantial economic and One Health challenges; however, comprehensive epidemiological data from China are limited. This study sought to ascertain the overall prevalence of key pathogens-namely, spp., , , and spp.-in equine populations in northwestern China. In this study, we aimed to further elucidate the characteristics of co-infections, profile antimicrobial resistance genes, and identify associated risk factors. Conducted as a cross-sectional analysis across four provinces, we collected 508 blood samples and 24 abortion tissue samples from 15 farms. Pat...
Sohn Y, An SJ, Forbes E, Yoon J, Kim BS, Ryu SH, Lee I.Osteochondritis dissecans (OCD) is a developmental orthopedic condition in young horses. Exercise and management affect OCD development, but the impact of exercise patterns during the 6-12 months growth period remains unclear. This study examined the association between OCD lesions in Thoroughbred foals and irregular exercise patterns. Forty foals wore halter-mounted Global Positioning System devices that recorded velocity every five seconds during turnout. Foals were routinely turned out for approximately 13 h daily, except on rainy days. Radiographs were taken at six and twelve months of a...
Deniz Ö, Erol HS, van den Hoven R, Onmaz AC, Aragona F, Fazio F.Weaning represents a major developmental milestone for foals, especially when 4- to 7-month-old foals are abruptly separated from their dams. Studies have shown that the post-weaning period is associated with physiological and psychological stress, which may affect immune function. The present study aimed to describe and analyze the pattern of blood inflammatory biomarkers related to the innate immune system. A gradual foal-dam separation procedure was chosen, which included post-weaning social buffering by a familiar adult horse. Twelve Thoroughbred foals (six fillies, six colts) aged 4-6 mon...
Nowicka B, Łopuszyński W, Krajewska-Wędzina M, Biazik A, Sobuś M, Polkowska I, Szacawa E.Gastrointestinal mycobacteriosis in horses is difficult to diagnose because of the pathogen's intracellular nature and the non-specific clinical symptoms. Effective accurate diagnosis facilitates prognosis and treatment. Current diagnostic procedures and methods of collecting material do not permit definitive antemortem diagnosis. However, culturing, acid-fast bacilli staining, histopathology, PCR and immunological marker evaluation may prove useful. Unassigned: Three horses were admitted to a clinic for intensive care and a final diagnosis. Physical examination and additional tests were perfo...
Southwood LL, Long A, Perez J, Daniel S, Bittinger K, Aitken M, Redding L.Based on human studies, surgical antimicrobial (AMD) prophylaxis (SAP) beyond 24 h is unnecessary and potentially detrimental. Objective: To compare clinical and microbiological outcomes in patients receiving 24- or 72-h of SAP for colic surgery. Methods: Prospective randomised clinical trial. Methods: Horses that recovered from colic surgery were considered. Exclusion criteria were (1) age <2 years; (2) Miniature Horses, pony, and draught breeds; (3) azotaemia; (4) recent hospitalisation, colic surgery, or AMDs; (5) local AMD administration. Eligible horses were randomly assigned to recei...
Page AE, McPeek JL, Carattini S, McGreevy E, Adam E.The goal of this project was to examine the metabolic effects of IA methylprednisolone acetate (MPA) following injection into multiple low-motion joints. Unassigned: Six 3-year-old geldings without pituitary pars intermedia dysfunction or insulin dysregulation were randomly injected with 20 mg of IA MPA/joint (80 mg total; bilateral distal hock joints) or an equal volume of saline. Serial blood samples were collected for resting ACTH, cortisol, insulin, and glucose, as well as insulin and glucose following repeated low-dose oral sugar tests. Treatments were crossed over after a 6-week washout,...
Rudeekiatthamrong A, Nguyen GT, Kamyingkird K. infection (Surra) remains a major constraint to equine health and productivity in Thailand. The only available trypanocidal drug, diminazene aceturate (DA), has limited efficacy, poor blood-brain barrier penetration, and toxicity in horses. This study aimed to investigate the inhibitory effects of commonly used equine antibiotics, gentamicin (GMC), ceftiofur (CTF), and trimethoprim-sulfamethoxazole (TS), against (Thai strain isolated from dairy cattle number 953; TEDC 953) to identify potential therapeutic alternatives or adjuncts for equine trypanosomosis. Unassigned: An growth inhibition...
Barua S, Tarannum A, Huber L, Easterwood LA, Velayudhan B, Da Silveira BP, Enyetornye B, Cohen ND, Dimitrov KM, Schwarz ER, Awtrey A, Groover E....Over the past decade, newly identified equine hepatotropic flavi- and parvoviruses, such as equine parvovirus-hepatitis (EqPV-H) and equine hepacivirus (EqHV), have generated considerable scientific and clinical interest. Pegiviruses, including Pegivirus (P.) caballi and P. equi, are also recognized and known to frequently cause persistent infections. However, comprehensive epidemiological data in the United States remain limited. This study analyzed 1195 equine serum samples collected from university-owned horses and diagnostic submissions across Alabama, Georgia, and Texas. Quantitative PCR ...
Environmental contamination with heavy metals, resulting from industrialization, urbanization, and agricultural intensification, poses serious ecological and health risks. Horses, due to their grazing behavior and close association with human environments, serve as reliable sentinel species for assessing environmental pollution. This study aimed to evaluate the bioaccumulation of heavy metals and trace elements in different biological matrices of horses-blood, hair, hooves, and synovial fluid-and to investigate their relationship with hematological biomarkers as indicators of physiological str...
Ma X, Zhang M, Zhang X, Qi T, Zhang W, Zhao Y, Na L, Zhang Y, Wang XF, Wang X.African horse sickness (AHS) is a lethal vector-borne disease caused by African horse sickness virus (AHSV) and represents a major threat to equine health and the horse industry. In 2020, outbreaks of AHS caused by AHSV serotype 1 (AHSV-1) were reported in Thailand, increasing the risk of AHS introduction into China. Given the safety issues associated with currently available live attenuated AHS vaccines, the development of safer and more effective vaccination strategies is urgently needed. In this study, we constructed a recombinant fowlpox virus (rFPV) expressing the AHSV-1 VP2 protein as a ...
Ricard A, Deretz S, Menard C, Priest BDS.The objective was to evaluate the genetic relationship between the surface temperature of regions of interest, measured using infrared images of young horses and functional longevity in jumping. This relationship was assessed by comparing the temperatures measured in the offspring of two groups of sires, one favourable and one unfavourable, to longevity. The study used a specific data collection protocol on a sample of 921 young progeny, before they began competing, of 141 extreme stallions, comprising 61 favourable and 80 unfavourable sires. These stallions had been selected based on estimate...
Mendoza Cerna MN, Anderson H, Avni G, Kahila Bar-Gal G, Juras R, Raudsepp T.Robertsonian translocations (ROBs) or centric fusions of acrocentric chromosomes are the most common structural chromosomal rearrangements in mammals. ROBs are of medical and veterinary concern because of associated subfertility and congenital disorders but are also of interest as a mechanism of chromosome and karyotype evolution. While ROBs are well documented in humans, mice, and cattle/bovids, they are extremely rare in horses, despite the 18 acrocentric chromosomes in the horse karyotype. Methods: We characterize the case using conventional and molecular cytogenetic approaches and DNA anal...
Satué K, Fauci D, Fazio E, Velasco-Martínez MG, Bruschetta G, Medica P.This study investigates sequential changes in serum protein fractions during gestation in 31 pregnant Spanish Purebred mares compared to 15 non-pregnant control. Total serum proteins (TSP) were measured using the Biuret method, while albumin (ALB), total globulins (tGLOB), and their subfractions (α₁, α₂, β₁, β₂, γ-GLOB) were analyzed by agarose gel electrophoresis. Pregnant mares showed significant changes in serum protein profiles throughout gestation. TSP and tGLOB concentrations increased from mid to late pregnancy (months 6-11), while ALB concentrations declined between months...
El-Geneady MA, Ramadan RM, Mahdy OA, Kamel MS, Salem MA.Hippobosca equina, a common ectoparasite of horses, poses a significant challenge to equine health worldwide. This study provides a molecular characterization of H. equina and examines its impact on host immune responses and oxidative stress. Genetic analysis of samples from various regions revealed notable homogeneity, indicating limited genetic variation among populations. Phylogenetic analysis demonstrated close genetic relationships among sequences from Egypt, France, Kazakhstan and Portugal, while also showing comparable but more distant identities to sequences from China, Denmark, Finlan...
Frey K, Perlini M, Reed R.Intravenous (IV) contrast administration during computed tomography (CT) of the equine head is routinely performed to delineate the extent of disease and differentiate between vascular and nonvascular tissue. Current equine scan protocols are extrapolated from human and canine studies. There have been no prospective equine studies describing the optimal time to image the patient after administration of contrast or the optimal site of contrast administration. Therefore, the current postcontrast times to scan and sites of contrast administration may not be appropriate for use in horses. The obje...
Silva JG, Martins KR, Rahal NM, Schuch LFD, Cunha RC, Meireles MCA.Neorickettsia risticii, an obligate intracellular bacterium, is the causative agent of Potomac Horse Fever (PHF) - a systemic, acute, and potentially fatal diarrheal disease. This pathogen is an endosymbiont of digenetic trematodes, with freshwater snails playing a role in its biological cycle. The disease exhibits endemic and seasonal patterns, primarily affecting horses in wetlands during warmer months, and has been documented in the United States, Canada, Europe, and South America. Previous studies confirmed the pathogen's presence in herds from southern Brazil via serology and PCR; however...
Otero JC, Neild DM, Ferrante AA, Gambarotta MC, Caldevilla ML.Glycerol, a penetrating cryoprotectant, is most employed for deep freezing spermatozoa. However, it can induce toxic, chemical, and osmotic effects, altering the lipid structure of the sperm membrane. Rapid glycerol addition has been demonstrated to have fewer toxic effects than its removal. Objective: To minimize both the toxic and osmotic effects of glycerol on equine sperm through post-thaw dilution using two different extenders. Methods: Samples of equine semen frozen with 5% glycerol from nine stallions were thawed, re-diluted 1:2, and incubated for 30 minutes at 22°C in Tyrodes (Tyr) an...
Atasoy MO, Turan T, Özbek R, Işıdan H, Naggar RFE, Afify AF, Rohaim MA.The genus (HCV) has long been a dynamic group, increasing its number by myriads of species collectively referred to as non-primate hepaciviruses (NPHVs). NPHV exhibits a broad hepatotropism and is often attributed to chronic infection in horses and dogs. However, recent studies and meta-analyses on NPHV in horses have remained inconclusive regarding the determination of risk factors for infection. Therefore, our main goal was to investigate the frequencies and molecular characteristics of NPHV infection linked to geographical location, horse breeds, genders, and ages. For this purpose, we tes...
Yerlikaya Z, Miranda-CasoLuengo R, Jahns H, Byrne O, Meijer WG, Mulcahy G, Walshe N.Cyathostomins are the most prevalent and currently considered the most pathogenic gastrointestinal nematodes in horses. Their life cycle includes an encystment phase within the large intestinal mucosa, where up to 90 % of the total worm burden resides. Clinical disease ranges from chronic protein-losing enteropathy to acute, sometimes fatal, typhlocolitis. Despite their significance, the ecological interplay between cyathostomins, the host immune response, and the gut microbiota remains poorly understood. To our knowledge, this is the first study to investigate these interactions at the mucos...
James AL, Vettorato E, Moura RA, Azevedo TMBPR, Mallicote MF, Chiavaccini L.Sedation with α₂-agonists can impair microcirculation and oxygen delivery. This prospective randomized crossover study investigated whether administering acepromazine maleate before detomidine hydrochloride maintains higher peripheral tissue oxygen saturation (StO₂) in sedated horses. Eight healthy adult horses randomly received intravenous detomidine (10 μg/kg) either alone (D) or in combination with acepromazine (20 μg/kg; DA), with a one-week washout. Hemoglobin concentration and central venous oxygen saturation (ScvO₂) were measured at baseline. Tissue oxygen saturation, tissue ...
Ramírez-Juidias E, Díaz de la Serna-Moreno Á, Delgado-Pertíñez M.Rangeland degradation poses a serious challenge for the sustainable management of free-ranging livestock in Mediterranean wetlands. In National Park, Spain, the endangered horse depends exclusively on natural forage, making it essential to monitor vegetation productivity and grazing suitability under increasing climate variability. This study presents a satellite-based assessment of rangeland carrying capacity to support the adaptive management of this iconic breed. A six-year time series (2015-2020) of 1242 images from Landsat 8 OLI/TIRS and Sentinel-2 (L1C/L2A) was processed using ILWIS an...
Posada-Guzmán MF, Jiménez-Rocha AE, Sánchez-Bermúdez JF, Romero-Zúñiga JJ, Dolz G.Equine piroplasmosis, caused by Babesia caballi and Theileria equi, is endemic in Costa Rica. However, the presence of these hemoparasites in tick vectors has not been documented in the country. Objective: To identify tick species infesting horses in four Indigenous communities and to determine the presence of B. caballi and T. equi DNA in ticks from piroplasmosis-positive horses. Methods: Ticks (n = 1063) were collected from 129 horses in four Indigenous communities. Species identification and sex classification were performed. From 76 PCR-positive horses, 203 ticks were analyzed for B. cabal...
Healy SR, Yaffy D, Miller HG.Setaria equina is a species of filarial nematode parasite transmitted by mosquitoes, which infects horses and other equids. Adult worms reside in the abdominal cavity with apparently little pathogenic significance, but larvae can migrate to other regions of the body with resulting clinical disease. Cases in the UK are rare, with the last published report in 2001. A recent case of S. equina infection was detected in a 13-year-old, UK-resident mare during postmortem examination in Hertfordshire, UK. Adult worms were collected from the abdominal cavity, their DNA extracted and subjected to PCR an...
van den Broek M, Chan ZYS, De Bruyne C, Garcia-Alamo K, Skotarek Loch S, Pfau T.Increased risk of musculoskeletal injury in galloping racehorses has been linked to decreased stride length and reduced speed over consecutive races prior to the injury. As racetrack curvature influences horses' maximal speed, we hypothesized it also affects stride parameters. During training sessions, twenty-eight wagon-pulling Thoroughbred Chuckwagon horses were equipped with Global Navigation Satellite System (GNSS) loggers, allowing for identification of speed, stride length (SL) and stride frequency (SF), and average speed, SL and SF were calculated for consecutive 100 m sections. Effects...
Willems T, Dias ABM, Dedecker L, Matamalas SS, De Lange L, de Beauregard T.Nephrosplenic space entrapment (NSE) has reported recurrence rates of 8%‒23%, and closure of the nephrosplenic space (NSS) has been shown to lower the incidence. Described techniques for nephrosplenic space closure (NSC) with concurrent left dorsal displacement (LDD) of the colon at the time of surgery consist of reducing the displaced colon prior to closure. Methods: A retrospective study was performed to evaluate the medical records of horse undergoing NSC between 2017 and 2024. A total of 18 horses with LDD at time of NSC and 21 without displacement at time of NSC were evaluated. Short- a...
Ozger ZB, Cihan P, Ozaydin I.Artificial intelligence (AI) has emerged as one of the most transformative tools for developing clinical decision-support systems in veterinary medicine. Despite its growing use, its full potential remains underutilized in equine medicine, an area of both high economic and clinical importance. Accurate survival prediction in horses with colic is crucial for timely intervention and improved clinical outcomes. Methods: This study aimed to predict survival outcomes in horse colic cases by developing models that combine traditional machine-learning algorithms (XGBoost, Light Gradient Boosting Mach...
Tell LA.Aspergillosis is relatively uncommon in mammals, but dogs, horses, cows and dolphins are susceptible. On the other hand, aspergillosis is a major cause of mortality in birds. This paper provides an overview of the manifestations of this disease in these animals. Treatment options are still lacking, but the increased incidence of the disease in humans has led to increased study, which may benefit both human and veterinary medicine.
Edson D, Field H, McMichael L, Vidgen M, Goldspink L, Broos A, Melville D, Kristoffersen J, de Jong C, McLaughlin A, Davis R, Kung N, Jordan D....Pteropid bats or flying-foxes (Chiroptera: Pteropodidae) are the natural host of Hendra virus (HeV) which sporadically causes fatal disease in horses and humans in eastern Australia. While there is strong evidence that urine is an important infectious medium that likely drives bat to bat transmission and bat to horse transmission, there is uncertainty about the relative importance of alternative routes of excretion such as nasal and oral secretions, and faeces. Identifying the potential routes of HeV excretion in flying-foxes is important to effectively mitigate equine exposure risk at the bat...
Ali A, Khan MA, Zahid H, Yaseen PM, Qayash Khan M, Nawab J, Ur Rehman Z, Ateeq M, Khan S, Ibrahim M.Although ticks prevalent in various agro-systems of Pakistan are associated with economic losses, information is still missing about the tick's diversity, hosts they infest, seasonal dynamics and molecular phylogeny of in Khyber Pakhtunkhwa (KP) Pakistan. This study for the first time enlisted ticks infesting diverse hosts including humans in various regions of KP. A total of 8,641 ticks were collected across the northern, southern and central regions of KP and were morpho-taxonomically categorized into six genera comprising 17 species, ( = 3,584, 42%), ( = 2,253, 27%) ( = 1,342, 16%), ( =...
Thorpe CT, Godinho MSC, Riley GP, Birch HL, Clegg PD, Screen HRC.While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of...
Witte TH, Knill K, Wilson AM.Measurement of peak vertical ground reaction force (GRFz) from multiple limbs simultaneously during high-speed, over-ground locomotion would enhance our understanding of the locomotor mechanics of cursorial animals. Here, we evaluate the accuracy of predicting peak GRFz from duty factor (the proportion of the stride for which the limb is in contact with the ground). Foot-mounted uniaxial accelerometers, combined with UHF FM telemetry, are shown to be practical and accurate for the field measurement of stride timing variables, including duty factor. Direct comparison with the force plate produc...
Soave O, Brand CD.Coprophagy is performed by rodents and lagomorphs and to a lesser degree by piglets, foals, dogs and nonhuman primates. Due to the construction of the digestive system of rodents and rabbits, coprophagy is necessary to supply many essential nutrients. Bacterial synthesis of nutrients occurs in the lower gastrointestinal tract in these animals where little absorption is realized. The eating of their feces provides a method for obtaining these nutrients.
Carpenter S, Mellor PS, Fall AG, Garros C, Venter GJ.African horse sickness virus (AHSV) is a lethal arbovirus of equids that is transmitted between hosts primarily by biting midges of the genus Culicoides (Diptera: Ceratopogonidae). AHSV affects draft, thoroughbred, and companion horses and donkeys in Africa, Asia, and Europe. In this review, we examine the impact of AHSV critically and discuss entomological studies that have been conducted to improve understanding of its epidemiology and control. The transmission of AHSV remains a major research focus and we critically review studies that have implicated both Culicoides and other blood-feeding...
Knowles DP, Kappmeyer LS, Haney D, Herndon DR, Fry LM, Munro JB, Sears K, Ueti MW, Wise LN, Silva M, Schneider DA, Grause J, White SN, Tretina K....A novel apicomplexan parasite was serendipitously discovered in horses at the United States - Mexico border. Phylogenetic analysis based on 18S rDNA showed the erythrocyte-infective parasite to be related to, but distinct from, Theileria spp. in Africa, the most similar taxa being Theileria spp. from waterbuck and mountain zebra. The degree of sequence variability observed at the 18S rDNA locus also suggests the likely existence of additional cryptic species. Among described species, the genome of this novel equid Theileria parasite is most similar to that of Theileria equi, also a pathogen of...
Lobigs M, Pavy M, Hall RA, Lobigs P, Cooper P, Komiya T, Toriniwa H, Petrovsky N.Advax is a polysaccharide-based adjuvant that potently stimulates vaccine immunogenicity without the increased reactogenicity seen with other adjuvants. This study investigated the immunogenicity of a novel Advax-adjuvanted Vero cell culture candidate vaccine against Japanese encephalitis virus (JEV) in mice and horses. The results showed that, in mice, a two-immunization, low-dose (50 ng JEV antigen) regimen with adjuvanted vaccine produced solid neutralizing immunity comparable to that elicited with live ChimeriVax-JE immunization and superior to that elicited with tenfold higher doses of a ...
Cunningham EP, Dooley JJ, Splan RK, Bradley DG.The thoroughbred (TB) horse is one of the oldest breeds of domestic animals, with pedigree records spanning three centuries. Because the population is essentially closed, there is concern about loss of genetic variation. Here we report two parallel analyses. In the first, genetic variation in the current population is measured using data from 13 microsatellite loci in 211 horses with relationships calculated based on allele sharing. In the second analysis, pedigree information is used to calculate genetic relationships between animals based on shared ancestry. These two measures of relationshi...
Vázquez-Boland JA, Giguère S, Hapeshi A, MacArthur I, Anastasi E, Valero-Rello A.Rhodococcus equi is a soil-dwelling pathogenic actinomycete that causes pulmonary and extrapulmonary pyogranulomatous infections in a variety of animal species and people. Young foals are particularly susceptible and develop a life-threatening pneumonic disease that is endemic at many horse-breeding farms worldwide. R. equi is a facultative intracellular parasite of macrophages that replicates within a modified phagocytic vacuole. Its pathogenicity depends on a virulence plasmid that promotes intracellular survival by preventing phagosome-lysosome fusion. Species-specific tropism of R. equi fo...
Canisso IF, Segabinazzi LGTM, Fedorka CE.Post-breeding endometritis (i.e., inflammation/infection of the endometrium), is a physiological reaction taking place in the endometrium of mares within 48 hours post-breeding, aimed to clear seminal plasma, excess sperm, microorganisms, and debris from the uterine lumen in preparation for the arrival of an embryo. Mares are classified as susceptible or resistant to persistent breeding-induced endometritis (PBIE) based on their ability to clear this inflammation/infection by 48 hours post-breeding. Mares susceptible to PBIE, or those with difficulty clearing infection/inflammation, have a def...
Costa MC, Weese JS.The equine intestinal tract contains a complex microbial population (microbiota) that plays an important role in health and disease. Despite the undeniable importance of a 'normal' microbiota, understanding of the composition and function of this population is currently limited. As methods to characterize the microbiota and its genetic makeup (the microbiome) have evolved, the composition and complexity of this population are starting to be revealed. As is befitting a hindgut fermenter, members of the Firmicutes phylum appear to predominate, yet there are significant populations of numerous ot...
Kumar N, Bera BC, Greenbaum BD, Bhatia S, Sood R, Selvaraj P, Anand T, Tripathi BN, Virmani N.Equine influenza viruses (EIVs) of H3N8 subtype are culprits of severe acute respiratory infections in horses, and are still responsible for significant outbreaks worldwide. Adaptability of influenza viruses to a particular host is significantly influenced by their codon usage preference, due to an absolute dependence on the host cellular machinery for their replication. In the present study, we analyzed genome-wide codon usage patterns in 92 EIV strains, including both H3N8 and H7N7 subtypes by computing several codon usage indices and applying multivariate statistical methods. Relative synon...
Matthews JB.Anthelmintics have been applied indiscriminately to control horse nematodes for over 40 years. Three broad-spectrum anthelmintic classes are currently registered for nematode control in horses: benzimidazoles (fenbendazole, oxibendazole), tetrahydropyrimidines (pyrantel) and macrocyclic lactones (ivermectin, moxidectin). Generally, control strategies have focused on nematode egg suppression regimens that involve the frequent application of anthelmintics to all horses at intervals based on strongyle egg reappearance periods after treatment. The widespread use of such programmes has substantial...
van Duijkeren E, Moleman M, Sloet van Oldruitenborgh-Oosterbaan MM, Multem J, Troelstra A, Fluit AC, van Wamel WJ, Houwers DJ, de Neeling AJ....At the Veterinary Microbiological Diagnostic Center, the Netherlands, the percentage of methicillin-resistant Staphylococcus aureus (MRSA) isolates found in equine clinical samples increased from 0% in 2002 to 37% in 2008. MRSA of spa-type t064, belonging to MLST ST8 and spa-types t011 and t2123, both belonging to the livestock-associated MLST ST398, predominated. During an outbreak of post-surgical MRSA infections in horses at a veterinary teaching hospital in 2006/2007, MRSA isolates of spa-type t2123 were cultured from 7 horses and 4/61 personnel which indicated zoonotic transmission. After...
Vilstrup JT, Seguin-Orlando A, Stiller M, Ginolhac A, Raghavan M, Nielsen SC, Weinstock J, Froese D, Vasiliev SK, Ovodov ND, Clary J, Helgen KM....The genus Equus is richly represented in the fossil record, yet our understanding of taxonomic relationships within this genus remains limited. To estimate the phylogenetic relationships among modern horses, zebras, asses and donkeys, we generated the first data set including complete mitochondrial sequences from all seven extant lineages within the genus Equus. Bayesian and Maximum Likelihood phylogenetic inference confirms that zebras are monophyletic within the genus, and the Plains and Grevy's zebras form a well-supported monophyletic group. Using ancient DNA techniques, we further charact...
Proops L, McComb K.It has recently been shown that some non-human animals can cross-modally recognize members of their own taxon. What is unclear is just how plastic this recognition system can be. In this study, we investigate whether an animal, the domestic horse, is capable of spontaneous cross-modal recognition of individuals from a morphologically very different species. We also provide the first insights into how cross-modal identity information is processed by examining whether there are hemispheric biases in this important social skill. In our preferential looking paradigm, subjects were presented with t...
Posthuma CC, Pedersen KW, Lu Z, Joosten RG, Roos N, Zevenhoven-Dobbe JC, Snijder EJ.The replication/transcription complex of the arterivirus equine arteritis virus (EAV) is associated with paired membranes and/or double-membrane vesicles (DMVs) that are thought to originate from the endoplasmic reticulum. Previously, coexpression of two putative transmembrane nonstructural proteins (nsp2 and nsp3) was found to suffice to induce these remarkable membrane structures, which are typical of arterivirus infection. Here, site-directed mutagenesis was used to investigate the role of nsp3 in more detail. Liberation of the hydrophobic N terminus of nsp3, which is normally achieved by c...
Prokhorov NS, Riccio C, Zdorovenko EL, Shneider MM, Browning C, Knirel YA, Leiman PG, Letarov AV.Bacteriophages recognize and bind to their hosts with the help of receptor-binding proteins (RBPs) that emanate from the phage particle in the form of fibers or tailspikes. RBPs show a great variability in their shapes, sizes, and location on the particle. Some RBPs are known to depolymerize surface polysaccharides of the host while others show no enzymatic activity. Here we report that both RBPs of podovirus G7C - tailspikes gp63.1 and gp66 - are essential for infection of its natural host bacterium E. coli 4s that populates the equine intestinal tract. We characterize the structure and funct...
Bi X, Li G, Doty SB, Camacho NP.The orientation of collagen molecules is an important determinant of their functionality in connective tissues. The objective of the current study is to establish a method to determine the alignment of collagen molecules in histological sections of cartilage by polarized Fourier transform infrared imaging spectroscopy (FT-IRIS), a method based on molecular vibrations. Methods: Polarized FT-IRIS data obtained from highly oriented tendon collagen were utilized to calibrate the derived spectral parameters. The ratio of the integrated areas of the collagen amide I/II absorbances was used as an ind...
Thompson JM, Whitmore AC, Konopka JL, Collier ML, Richmond EM, Davis NL, Staats HF, Johnston RE.Vaccination represents the most effective control measure in the fight against infectious diseases. Local mucosal immune responses are critical for protection from, and resolution of, infection by numerous mucosal pathogens. Antigen processing across mucosal surfaces is the natural route by which mucosal immunity is generated, as peripheral antigen delivery typically fails to induce mucosal immune responses. However, we demonstrate in this article that mucosal immune responses are evident at multiple mucosal surfaces after parenteral delivery of Venezuelan equine encephalitis virus replicon pa...
Lupo A, Saras E, Madec JY, Haenni M.In Asian countries, blaCTX-M-55 is the second most common ESBL-encoding gene. blaCTX-M-55 frequently co-localizes with fosA and rmtB genes on epidemic plasmids, which remain sporadic outside Asia. During 2010-13, we investigated CTX-M-55-producing Escherichia coli isolates and their co-resistance to fosfomycin, aminoglycosides, fluoroquinolones and colistin as part of a global survey of ESBLs in animals in France. blaCTX-M-55, fosA, rmtB and plasmidic quinolone and colistin resistance genes were characterized by PCR, sequencing and hybridization experiments. Plasmids were classified according ...
Baker TS, Newcomb WW, Booy FP, Brown JC, Steven AC.Cryoelectron microscopy and three-dimensional computer reconstruction techniques have been used to compare the structures of two types of DNA-free capsids of equine herpesvirus 1 at a resolution of 4.5 nm. "Light" capsids are abortive, whereas "intermediate" capsids are related to maturable intracellular precursors. Their T = 16 icosahedral outer shells, approximately 125 nm in diameter, are indistinguishable and may be described in terms of three layers of density, totalling 15 nm in thickness. The outermost layer consists of protruding portions of both the hexon and the penton capsomers, ris...
Cross AR, Higson FK, Jones OT, Harper AM, Segal AW.1. The absorption coefficient of human neutrophil plasma-membrane reduced-minus-oxidized cytochrome b-245 was determined [delta epsilon (mM; 559-540 nm) = 21.6 cm-1]. 2. Neutrophil polymorphonuclear leucocytes (neutrophils) were prepared from human, ox, horse and pig blood. In each case plasma-membrane fractions were found to contain low-potential cytochrome b. When membranes from horse neutrophils were incubated anaerobically with either NADH or NADPH the cytochrome b became reduced. Prior stimulation of the cells with phorbol myristate acetate did not increase the rate or extent of cytochrom...
Smith RK, Zunino L, Webbon PM, Heinegård D.A protein prominent in guanidine hydrochloride extracts of adult bovine and equine digital flexor tendons was confirmed to be Cartilage Oligomeric Matrix Protein (COMP) by non-reducing and reducing SDS-PAGE, reaction with rabbit anti-COMP polyclonal antiserum on Western blots, trypsin digestion followed by HPLC on a C2/C18 column, and identification of COMP mRNA from tendon on Northern blots. Immunohistochemistry and Western blots of extracts showed COMP to be present in all regions of digital flexor tendons. Equine tendon COMP was purified by ion exchange chromatography and gel filtration and...
Pfau T, Witte TH, Wilson AM.Biomechanical studies often employ optical motion capture systems for the determination of the position of an object in a room-based coordinate system. This is not ideal for many types of study in locomotion since only a few strides may be collected per ;trial', and outdoor experiments are difficult with some systems. Here, we report and evaluate a novel approach that enables the user to determine linear displacements of a proprietary orientation sensor during cyclical movement. This makes experiments outside the constraints of the laboratory possible, for example to measure mechanical energy ...
Barberini DJ, Freitas NP, Magnoni MS, Maia L, Listoni AJ, Heckler MC, Sudano MJ, Golim MA, da Cruz Landim-Alvarenga F, Amorim RM.Studies with mesenchymal stem cells (MSCs) are increasing due to their immunomodulatory, anti-inflammatory and tissue regenerative properties. However, there is still no agreement about the best source of equine MSCs for a bank for allogeneic therapy. The aim of this study was to evaluate the cell culture and immunophenotypic characteristics and differentiation potential of equine MSCs from bone marrow (BM-MSCs), adipose tissue (AT-MSCs) and umbilical cord (UC-MSCs) under identical in vitro conditions, to compare these sources for research or an allogeneic therapy cell bank. Methods: The BM-MS...
Giguère S, Viel L, Lee E, MacKay RJ, Hernandez J, Franchini M.Work in humans and laboratory animals has identified a central role for cytokines and chemokines in development and persistence of lower airway inflammation. The objectives of this study were to determine interleukin (IL)-1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha induction in bronchoalveolar lavage (BAL) of control horses and horses with heaves both during remission and exacerbation of the disease, and to determine the effect of therapy with inhaled fluticasone propionate on the cytokine profile of horses with heaves. IL-1 beta an...
