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.
Adler DMT, Nielsen AT, Olsen C, Verwilghen D, Damborg P, Olsen RH.To investigate the in vitro efficacy of antibiotics (amikacin, ceftiofur, and gentamicin) in combination with local anesthetics (LAs; bupivacaine hydrochloride, lidocaine hydrochloride, and mepivacaine hydrochloride), a combination commonly performed for IA injectate and regional limb perfusion (RLP) in horses. Unassigned: 17 equine clinical isolates were tested by the checkerboard method for their minimum inhibitory concentration (MIC) against a combination of concentrations of LAs and antibiotics from August 2020 through December 2023. Unassigned: For the majority of combinations, the antibi...
Risvanli A, Hatipoglu F, Salykov R, Timurkaan N, Kadiralieva N, Kasymalieva KK, Seker I, Ekinci E.In the current study, we aimed to determine the distribution of telocytes in the ovary, oviduct and uterus of Kyrgyz mares depending on whether they were pregnant. We also studied the progression during the first 6 months of pregnancy. To this end, ovary, oviduct and uterus tissues from 53 Kyrgyz mares were obtained post-mortem. The mare tissue samples were divided into two groups: pregnant (n = 43) and non-pregnant (n = 10). Telocyte levels in the tissues were determined using light microscopic and immunohistochemical methods. Subsequently, the data acquired were evaluated based on ...
Fernandes TA, Paulino PG, Dos Santos Juliano D, Rabello CA, de Oliveira NVB, de Souza Santana M, Peckle M, Massard CL, da Costa Angelo I, Jacob JCF....Equine piroplasmosis (EP) is a reportable disease according to the World Organization for Animal Health (WOAH), caused by Babesia caballi, Theileria equi and T. haneyi. This syndrome is prevalent in tropical and subtropical regions, including various areas in Brazilian. This study examines EP in the Distrito Federal, Brazil, focusing on prevalence, epidemiological characteristics, and circulating genotypes. Epidemiological data and whole blood samples were collected from horses in the Distrito Federal. DNA was analyzed using qPCR for Theileria sp. and B. caballi, followed by cPCR for 18S rDNA ...
Asif S, Gulzar MW.Endometritis is a significant cause of infertility in mare. Some infectious agents disrupt the endometrium's innate immune system, resulting in a prolonged systemic inflammatory response that circulates via the blood or cellular degeneration, which ultimately leads to endometritis from bacterial endotoxins. Numerous biological processes use various small, non-coding RNA molecules called MicroRNAs. MicroRNAs (miRNAs) regulate gene expression after transcription by blocking transcription and translation. This manuscript examines patho-morphological discoveries in equine endometritis, the express...
Parente A, Geburek F, Kästner S, Iversen C, Hopster K.Orotracheal intubation is commonly performed for inhalation anaesthesia in horses to ensure safe and reliable administration of volatile anaesthetics and to secure the airways. In human and equine medicine, the occurrence of intubation-associated complications has been described, which can range from mild mucosal irritation to severe necrosis. However, there are only sparse descriptions of mucosal alterations and the course of healing after elective surgery in horses. Objective: To investigate the prevalence and severity of tracheal lesions following endotracheal intubation associated with gen...
Vaccination is one of the most important measures for preventing infectious diseases. Vaccinations against tetanus and West-Nile-Virus are essential to protect the individual horse. These infections are not contagious and are not transmitted from animal to animal. By contrast, Equine Influenza and Equine-Herpes-Virus infections are highly contagious, transmissible diseases. In addition to protecting the vaccinated individual, vaccinating as many horses as possible aims at inducing a broad herd immunity, which interrupts infection chains and thus additionally protects the individual. Vaccinatio...
In February 2021, a serious EHV-1 outbreak occurred at an international jumping competition in Valencia, with several subsequent outbreaks in various European countries. As a consequence, several equestrian associations introduced compulsory vaccination against EHV-1, and in the immediate aftermath of the outbreak, demand for EHV vaccinations increased sharply. The initial concern has now dissipated. One equestrian association has abolished the compulsory vaccination that had only been introduced a year before, and a general debate began questioning the efficacy and safety of EHV-vaccines. Thi...
Macías-Rioseco M, Ochoa J, Choi EA, Blanchard P, Moeller RB, Uzal FA. spp. can cause gastroenteritis, hepatitis, bacteremia, and abortions in domestic animals and humans. Some spp. are zoonotic. To our knowledge, hepatitis caused by has not been reported in horses. Here we present a case of acute necrosuppurative hepatitis caused by infection in a 3-y-old gelding, and we review the literature on infections in various animal species. The horse had a one-week history of weight loss and weakness before becoming recumbent and dying. Grossly, the liver had rounded edges and was mottled. There were ecchymoses on the gastric serosa, and a large amount of mucoid, p...
Li D, Wang X, Yao J, Chen S.Adipose tissue-derived extracellular vesicles (ATEVs) have garnered attention for their roles in intercellular communication and regulation. This study presents the first investigation of equine adipose tissue, with ATEV being extracted concurrently during the isolation of adipose-derived mesenchymal stem cells (ADSCs). Through CCK-8 cell proliferation assays and scratch migration assays, a significant promotional effect of ATEV on ADSCs was observed, which not only accelerated the proliferation rate of the stem cells but also enhanced their migratory capacity. The application of Trypan Blue e...
Guo W, Li Z, Mao W, Liu X, Yang Y, Yu J, Yang H, Gao R.Flunixin meglumine (FM) is commonly used in painful conditions in horses; however, it may contribute to equine gastric ulcer syndrome (EGUS). Some veterinarians combine omeprazole (OME) and FM to reduce EGUS risk. However, the efficacy and safety of this combination in Mongolian horses with chronic lameness remain unknown. Objective: To investigate the changes in lameness and EGUS scores in Mongolian horses through the comparison of three treatment strategies: FM, FM + OME and placebo treated control (CON) and to assess the effects of these treatments on gastric fluid pH, serum total prote...
Guzmán JFC, Gontijo AS, Melgaço ES, Faria SA, Baldi MLC, Sousa LN, Wenceslau RR, Fantini P, Xavier ABDS, Beier SL.Morphine has significant clinical and analgesic effects in horses, but its impact on the gastrointestinal tract requires further understanding. This study assessed the analgesic and gastrointestinal effects of morphine in horses undergoing elective orchiectomy in the quadrupedal position. Thirty uncastrated male horses were randomly assigned to three groups: orchiectomy without morphine and sedation protocol (OSM), orchiectomy with morphine and sedation protocol (OM), and administration of morphine alone in the absence of orchiectomy (M). The anesthetic protocol involved acepromazine (0.05 mg/...
Skurková L, Matulníková L, Peťková B, Florian M, Slivková M, Lešková L, Mesarčová L, Kottferová J.This study aimed to assess the seasonal changes of the cortisol concentrations in horsehair (HCC), as an indicator of long-term or chronic stress. Hair samples were taken four times throughout one year from 12 horses (aged from 1.5 to 30 years), and analysed by the ELISA method. The sampling interval (interval between two collections of the samples representing two different seasons) ranged between 102-115 days. Seasonal dynamics have been confirmed with a pattern: August ˃ November ˃ January ˃ April (F (3.93) = 50.28, P < 0.001). The lowest cortisol concentrations were detected in A...
Ajeeb B, Kiyotake EA, Keefe PA, Phillips JN, Hatzel JN, Goodrich LR, Detamore MS.Cartilage injuries pose significant challenges in horses and often lead to post-traumatic osteoarthritis (PTOA). Despite the advances in surgical and regenerative techniques, the result in most cases is the formation of a fibrocartilage repair tissue. Cell-based cartilage therapies are mainly focused on equine bone marrow-derived mesenchymal stem cells (eBMSCs) as they are easily accessible, and multipotent. Nonetheless, alternative allogeneic sources, for example equine umbilical cord matrix mesenchymal stromal cells (eUCMSCs), hold promise given their non-invasive and readily accessible natu...
Primo ALM, Assis DM, Santos VGS, de Melo LRB, da Nóbrega LD, Medeiros Dantas AF, Maciel TA.Cerebellar abiotrophy is a neurodegenerative disease that affects the Purkinje cells of the cerebellum, resulting in premature neuronal death. In horses, its occurrence has been reported mainly in the Arabian breed as a congenital mutation inherited in an autosomal recessive manner. The objective of this study was to describe the case of cerebellar abiotrophy in a Quarter Horse foal. An 8-day-old foal was treated after presenting signs of ataxia, hypermetria, difficulty maintaining a standing position, and decreased menace response. The foal was hospitalized for 26 days, received treatment wit...
van der Graaf L, Leigh W, Szmatoła T, Roberts K, Ryan S, Brown B, Van Buren S, Finno CJ, Petersen JL.Anhidrosis is defined as a decreased or absent ability to sweat in response to heat and exercise. In horses, this condition can increase the risk of life-threatening hyperthermia. A prior study has suggested that equine anhidrosis is associated with a missense variant (rs68643109) in the Potassium Voltage-Gated Channel Subfamily E Regulatory Subunit 4 (KCNE4) gene. This project aimed to validate this association in a population of well-phenotyped horses and to determine the allele frequency of this variant in publicly available whole-genome sequence data. Fifty horses within the University of ...
Fedorka CE, Scoggin KE, Coleman SJ, Hatzel JN, Burleson MD, Troedsson MHT.Alterations during the early stages of embryo development have been associated with long-term effects on the fetus, neonate, and adult, but this has not been investigated in horses. In recent years, intracytoplasmic sperm injection (ICSI) has gained in commercial popularity in the equine population. Research suggests an association between ICSI-produced embryos and placental malformations, but there exists little understanding of the physiology involved. Therefore, we aim to produce a complete transcriptomic analysis of chorioallantois and provide potential pathways that may be impacted follow...
Vandaele Z, Van den Broeke C, Merchiers A, Schauvliege S.Different assisted recovery techniques have been developed to enhance the safety and quality of equine recoveries. This case series evaluates the recovery of horses using an air-inflated pillow (Equi-lift®). With owner consent, the following data were collected from 19 horses undergoing open castration and 21 horses where a difficult recovery was anticipated: age, bodyweight, procedure, anaesthetic protocol, time required for proper positioning in the Equi-lift®, time to extubation, time to standing, number of attempts to stand, number of stimuli, behaviour during recumbency/first attempts, ...
Pezzanite LM, Nelson BB, Downey AC, Gadomski B, McGilvray K, Baer K, Kappel SM, Nout-Lomas Y, Seim HB, Easley JT.To determine the biomechanical properties of pedicle screw and rod (PSR) constructs alone and with an interbody fusion device (PSRIFD) for equine ventral cervical vertebral stabilization. Methods: Cadaveric ex vivo biomechanical analysis. Methods: A total of 14 (n = 14) adult equine cervical vertebral columns. Methods: Cervical vertebral columns were stabilized by PSR alone (n = 6) or PSRIFD (n = 5). Three columns were left unaltered as controls. Non-destructive biomechanical testing showed the kinematic range of motion (ROM), compliance, and neutral zone of each spinal unit in the...
Littiere TO, Costa GB, Sales NAA, Carvalho JRG, Rodrigues IDM, Ramos GV, Ferraz GC.In humans, there is an ongoing academic discussion about measuring plasma lactate concentration ([La]) during an incremental exercise test (IET) to establish thresholds that can predict the maximal lactate steady state (MLSS). Training studies on horses have utilized the onset of [La] (OBLA), also known as V, the velocity at which the [La] of 4 mM is reached. This study assesses the effectiveness of four methods for estimating the MLSS in teaching horses. Ten teaching horses underwent a single IET to determine four exercise intensity thresholds for predicting MLSS and performed several constan...
Perrone G, Giampaoli C, Smirnoff AL, Ochoa A, Pareja R, De Simone E.Osteoarthritis (OA) is the most common pathology in sport horses, presenting a chronic and recurrent course. Traditional anti-inflammatory treatments provide only temporary clinical improvement and pain relief; however, they have been associated with metabolic disorders in articular cartilage in the medium term. In this study, we generated a llama polyclonal antibody against equine TNF-α, which was used for intra-articular treatment in horses with OA. Treatment effects were assessed through clinical examination and the determination of inflammatory parameters (MMP-2, MMP-9, LDH, and GAGs) in ...
Lundblad J, Rhodin M, Hernlund E, Bjarnestig H, Hidén Rudander S, Haubro Andersen P.Facial expressions in prey animals such as equines can convey information regarding their internal state and are therefore often used as cues for welfare and pain evaluation. The state of pain is commonly compared to a neutral state with little consideration given to other experiences that could affect the animal, although this situation is rare outside of experimental contexts. To evaluate the effect of managerial contexts on facial expressions from a nociceptive input, conspecific isolation and sedation with known physiological effects were compared to compound states of nociception. Using a...
MacKechnie-Guire R, Clayton H, Williams J, Marlin D, Fisher M, Fisher D, Walker V, Murray R.Measuring tools designed to objectively determine equine noseband tightness are inserted on the dorsal nasal planum in a rostro-caudal direction. The lateral aspect of the horse's head has several areas where minimal soft tissue intervenes between the skin and underlying bone, which makes them potentially useful sites for measuring noseband tightness. One hundred horses were fitted with a snaffle bridle with a cavesson, Swedish or dropped noseband in random order. The tightness of each noseband type was adjusted sequentially to 2.0, 1.5, 1.0, 0.5 and 0.0 finger-equivalents using an ISES Taper ...
Barton CK, Nelson BB, Winther TM, Maker TC, Goodrich LR.To develop and optimize a tenoscopic technique for resection of the manica flexoria utilizing a radiofrequency probe. Methods: Experimental study. Methods: Eighteen cadaver limbs and two experimental horses. Methods: Tenoscopic-guided resection of the manica flexoria using radiofrequency energy proceeded sequentially by transection of the medial, lateral and proximal borders. The technique was performed in ex vivo limbs and then in vivo to replicate clinical scenarios. Time to complete resection of the manica flexoria (mean ± SD) and complications was recorded. Limbs were dissected and sc...
Feighelstein M, Ricci-Bonot C, Hasan H, Weinberg H, Rettig T, Segal M, Distelfeld T, Shimshoni I, Mills DS, Zamansky A.[This corrects the article DOI: 10.1371/journal.pone.0302893.].
Poizat E, Gérard M, Macaire C, De Azevedo E, Denoix JM, Coudry V, Jacquet S, Bertoni L, Tallaj A, Audigié F, Hatrisse C, Hébert C, Martin P....Lameness detection in horses is a critical challenge in equine veterinary practice, particularly when symptoms are mild. This study aimed to develop a predictive system using a support vector machine (SVM) to identify the affected limb in horses trotting in a straight line. The system analyzed data from inertial measurement units (IMUs) placed on the horse's head, withers, and pelvis, using variables such as vertical displacement and retraction angles. A total of 287 horses were included, with 256 showing single-limb lameness and 31 classified as sound. The model achieved an overall accuracy o...
O'Kennedy MM, Reedy SE, Abolnik C, Khan A, Smith T, du Preez I, Olajide E, Daly J, Cullinane A, Chambers TM.Equine influenza (EI) is a highly contagious acute respiratory disease of wild and domesticated horses, donkeys, mules, and other Equidae. EI is caused by the Equine Influenza virus (EIV), is endemic in many countries and outbreaks still have a severe impact on the equine industry globally. Conventional EI vaccines are widely used, but a need exists for a platform that facilitates prompt manufacturing of a highly immunogenic, antigenically matched, updated vaccine product. Here we developed a plant-produced bivalent EI virus-like particle (VLP) vaccine candidate which lacks the viral genome an...
Kerbert MP, le Jeune SS, Philips KL, Shaw KL, Erickson CA, Espinosa-Mur P.Back pain is a common cause of poor performance in horses. However, the relationship between clinical signs and radiographic abnormalities is unclear. The aim of this study was to report radiographic findings of spinous processes in a population of Warmblood jumping horses and their association with performance. This was a descriptive observational study. One hundred Warmblood jumping horses (competing fence height: median 1.35 m, mean 1.3 m, range 0.90m-1.60 m), with no observed lameness and neurological signs, competing in 2018 were selected. Radiographs of spinous processes of the thoracolu...
Bercovitz GR, Sullivan SN, Reed RA, Ryan CA, Diehl KA.To evaluate the effect of intravenous mannitol and hypertonic saline (HS) on intraocular pressure (IOP) and biometry parameters of horses with elevated intracranial pressure (ICP). Methods: Seven horses with normal ophthalmic exams were anesthetized and placed in lateral recumbency. A subarachnoid transducer was placed, and the head was lowered until ICP measured 40 mmHg +/- 2 mmHg. Five intravenous boluses of mannitol 20% (0.4 g/kg) or HS 7.2% (1 mL/kg) were administered, each 15 min apart. A 2-day washout period ensued, and the procedure was repeated with the other hyperosmotic age...
Basso RM, Cerri FM, Possebon FS, Braga PRC, Casas MRT, Oliveira-Filho JP, Araújo Júnior JP, Ribeiro MG, Arroyo LG, Borges AS. spp. are important pathogens of foals, causing clinical enterocolitis and sepsis. We characterized the resistance, virulence, and stress response genes in isolates from foals with or without diarrhea. isolates ( = 23) recovered from fecal samples of 16 diarrheic and 7 non-diarrheic <1-y-old foals were subjected to whole-genome sequencing. The most common serovars detected in diarrheic foals were subsp. serovars Infantis and Minnesota. Multidrug resistance was observed in 9 of 23 isolates, with 8 of the 9 from diarrheic foals. All of the isolates contained at least 2 resistance genes, ...
Ross M, Proudfoot K, Merkies K, Lundgren C, Ritter C.Competitive dressage's social licence to operate is in jeopardy due to ethical concerns surrounding the use of horses for dressage. There is limited research that contributes to our understanding of Canadian equestrian perspectives on the use of horses in dressage. The objectives of this study were to: (1) explore the cultural context of the Canadian dressage industry, including how horse well-being is integrated within the culture; and (2) investigate coaches' and riders' perceptions and experiences with the use of horses for dressage. An ethnographic case study approach was employed, where M...
Turner TA.Thermography is a practical aid in the clinical evaluation of the equine patient. It is particularly germane to the evaluation of lameness. This modality specifically increases the accuracy of diagnosis. Thermography is the pictorial representation of skin temperature. The technique involves the detection of infrared radiation, which can be directly correlated to blood flow. To be accurate, thermography must be performed in a controlled area free of drafts. The area should be protected from sunlight to avoid erroneous heating of the skin, and the horse's hair length should be uniform. Thermogr...
Theoret CL, Wilmink JM.Impaired wound healing represents an enormous clinical and financial problem for companion animals and humans alike. Unfortunately, most models used to study healing rely on rodents, which have significant differences in the healing and scarring process and rarely develop complications. In order to better simulate impaired healing, the model should strive to reproduce the natural processes of healing and delayed healing. Wounds on the limbs of horses display similarities to wounds in humans in their epithelialization/contraction ratio, genetic influence as well as dysregulated cytokine profile...
Richardson DW, Dodge GR.To determine the effects of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) on expression and regulation of several matrix-related genes by equine articular chondrocytes. Methods: Articular cartilage harvested from grossly normal joints of 8 foals, 6 yearling horses, and 8 adult horses. Methods: Chondrocytes maintained in suspension cultures were treated with various doses of human recombinant IL-1beta or TNF-alpha. Northern blots of total RNA from untreated and treated chondrocytes were probed with equine complementary DNA (cDNA) probes for cartilage matrix-related ge...
McPartlin LA, Suarez SS, Czaya CA, Hinrichs K, Bedford-Guaus SJ.Capacitation is a complex and not well-understood process that encompasses all the molecular changes sperm must undergo to successfully fertilize an oocyte. In vitro fertilization has remained elusive in the horse, as evidenced by low in vitro fertilization (IVF) rates (0%-33%); moreover, only two foals have ever been produced using IVF. Incubation of stallion sperm in modified Whittens supplemented with bovine serum albumin and sodium bicarbonate yielded significant rates of time-dependent protein tyrosine phosphorylation and induced acrosomal exocytosis, consistent with capacitation. The obj...
Qi M, Wang R, Wang H, Jian F, Li J, Zhao J, Dong H, Zhu H, Ning C, Zhang L.In present study, 262 fecal specimens were collected from 12 groups of grazing horses in the Xinjiang Uyghur Autonomous Region of China. The specimens were subjected to PCR and sequencing analyses of the ribosomal internal transcribed spacer (ITS). The overall prevalence of E. bieneusi in horses was 30.9% (81/262). No significant differences in prevalence were observed between horses of different ages or sexes. Nineteen genotypes were identified: 15 known genotypes (BEB6, CHG19, CM6, CM7, CM8, CS-1, CS-4, D, EpbA, EbpC, G, horse1, horse2, O, and Peru8) and four new genotypes (XJH1-XJH4). Six ...
Leemans B, Gadella BM, Stout TA, De Schauwer C, Nelis H, Hoogewijs M, Van Soom A.In contrast to man and many other mammalian species, conventional in vitro fertilization (IVF) with horse gametes is not reliably successful. The apparent inability of stallion spermatozoa to penetrate the zona pellucida in vitro is most likely due to incomplete activation of spermatozoa (capacitation) because of inadequate capacitating or fertilizing media. In vivo, the oviduct and its secretions provide a microenvironment that does reliably support and regulate interaction between the gametes. This review focuses on equine sperm-oviduct interaction. Equine sperm-oviduct binding appears to be...
Pomar FJ, Teerds KJ, Kidson A, Colenbrander B, Tharasanit T, Aguilar B, Roelen BA.The occurrence of pregnancies and births after embryo transfer (ET) of in vivo produced embryos is generally more successful compared to that of embryos produced in vitro. This difference in ET success has been observed when embryos of morphological equal (high) quality were used. The incidence of apoptosis has been suggested as an additional criterion to morphological embryo evaluation in order to assess embryo quality and effectively predict embryo viability. In this study, equine, porcine, ovine, caprine and bovine in vivo and in vitro produced morphologically selected high quality (grade-I...
McCarthy AJ, Lindsay JA, Loeffler A.Meticillin-resistant Staphylococcus aureus (MRSA) continues to pose a major threat to human health. In animals, MRSA has become established as a veterinary pathogen in pets and horses; in livestock, it presents a concern for public health as a reservoir that can infect humans and as a source of transferrable resistance genes. Genetic analyses have revealed that the epidemiology of MRSA is different in different animal hosts. While human hospital-associated MRSA lineages are most commonly involved in pet infection and carriage, horse-specific MRSA most often represent 'traditional' equine S. au...
Tozaki T, Miyake T, Kakoi H, Gawahara H, Sugita S, Hasegawa T, Ishida N, Hirota K, Nakano Y.Using 1400 microsatellites, a genome-wide association study (GWAS) was performed to identify genomic regions associated with lifetime earnings and performance ranks, as determined by the Japan Racing Association (JRA). The minimum heritability (h(2) ) was estimated at 7-8% based on the quantitative trait model, suggesting that the racing performance is heritable. Following GWAS with microsatellites, fine mapping led to identification of three SNPs on ECA18, namely, g.65809482T>C (P=1.05E-18), g.65868604G>T (P=6.47E-17), and g.66539967A>G (P=3.35E-14) associated with these performance ...
Mihm M, Evans AC.The selection of a single ovarian follicle for further differentiation and finally ovulation is a shared phenomenon in monovulatory species from different phylogenetic classes. The commonality of dominant follicle (DF) development leads us to hypothesize that mechanisms for DF selection are conserved. This review highlights similarities and differences in follicular wave growth between cows, mares and women, addresses the commonality of the transient rises in FSH concentrations, and discusses the follicular secretions oestradiol and inhibin with their regulatory roles for FSH. In all three spe...
Knollinger AM, La Croix NC, Barrett PM, Miller PE.To compare intraocular pressure (IOP) measurements obtained with a rebound tonometer in dogs and horses with values obtained by means of applanation tonometry and direct manometry. Methods: Prospective study. Methods: 100 dogs and 35 horses with clinically normal eyes, 10 enucleated eyes from 5 dogs, and 6 enucleated eyes from 3 horses. Methods: In the enucleated eyes, IOP measured by means of direct manometry was sequentially increased from 5 to 80 mm Hg, and IOP was measured with the rebound tonometer. In the dogs and horses, results of rebound tonometry were compared with results of applana...
Aurich C.Horses are long-day breeders. During the breeding season, cycle length is about 22 days with 5-7 days of oestrus. Gonadotroph cells are localized in the pars distalis as well the pars tuberalis of the pituitary and heterogeneity in the pattern of LH and FSH storage within the gonadotroph population is considered the basis for the differential regulation of gonadotrophin secretion throughout the reproductive cycle. No short and distinct periovulatory LH peak exists in the mare. The equine ovary has an extreme large size and weight. One to two major follicular waves develop per cycle. The preovu...
Ball JM, Rushlow KE, Issel CJ, Montelaro RC.We describe here a detailed analysis of the antigenic determinants of the surface unit glycoprotein (gp90) of equine infectious anemia virus (EIAV), using a comprehensive panel of synthetic peptides in enzyme-linked immunosorbent assays with immune serum from naturally and experimentally infected horses and with a panel of gp90-specific neutralizing and nonneutralizing monoclonal antibodies. The results of these studies identify immunoreactive segments throughout the conserved and variable domains of gp90 but localize immunodominant (100% reactivity) determinants to the amino and carboxyl term...
Perkins GA, Lamb S, Erb HN, Schanbacher B, Nydam DV, Divers TJ.Plasma ACTH levels have been variable in horses with a positive clinical response for therapy for equine Cushing's Disease (ECD). Therefore, our purpose was to determine the value of monitoring plasma adrenocorticotropin (ACTH) levels during treatment of equine Cushing's disease (ECD) with either cyproheptadine (n = 32) or pergolide (n = 10). First, we validated the chemiluminescent ACTH assay (specificity, precision, accuracy, intra-assay and interassay variations) and tested methods of handling the whole blood from the time of collection to when the ACTH was assayed. The sensitivity and spec...
Eivers SS, McGivney BA, Fonseca RG, MacHugh DE, Menson K, Park SD, Rivero JL, Taylor CT, Katz LM, Hill EW.Intense selection for elite racing performance in the Thoroughbred horse (Equus caballus) has resulted in a number of adaptive physiological phenotypes relevant to exercise; however, the underlying molecular mechanisms responsible for these characteristics are not well understood. Adaptive changes in mRNA expression in equine skeletal muscle were investigated by real-time qRT-PCR for a panel of candidate exercise-response genes following a standardized incremental-step treadmill exercise test in eight untrained Thoroughbred horses. Biopsy samples were obtained from the gluteus medius before, i...
Hewson CJ, Dohoo IR, Lemke KA, Barkema HW.Anecdotal evidence suggests that many veterinarians may not use analgesics in livestock for routine surgical procedures or painful disease states. To investigate this, we conducted a national mail survey of a random sample of 1431 Canadian veterinarians (response rate, 50.1%). Questions primarily concerned veterinarians' analgesic usage for common surgeries and medical conditions in beef and dairy cattle, pigs, and horses, and attitudes toward pain management. More than 90% of veterinarians used analgesic drugs for equine surgeries, for cesarean section in sows and cows, and for bovine claw am...
Kutasi O, Bakonyi T, Lecollinet S, Biksi I, Ferenczi E, Bahuon C, Sardi S, Zientara S, Szenci O.The spread of lineage 2 West Nile virus (WNV) from sub-Saharan regions to Europe and the unpredictable change in pathogenicity indicate a potential public and veterinary health threat and requires scientific awareness. Objective: To describe the results of clinical and virological investigations of the 1st outbreak of a genetic lineage 2 WNV encephalomyelitis in horses. Methods: Seventeen horses with neurologic signs. Methods: Information regarding signalment, clinical signs, and outcome was obtained for each animal. Serology was performed in 15 cases, clinicopathological examination in 7 case...
Haber M, Cao Z, Panjwani N, Bedenice D, Li WW, Provost PJ.The physiologic mechanisms involving growth factors, including PDGF-BB, EGF, and TGF-beta 1, as potent mediators of fibroblasts and epithelial cells in corneal wound healing remain unknown. The goal of this study was to determine culture methods for equine epithelial cells and keratocytes and to investigate how exogenous growth factors influence proliferation of both cell types. Methods: Cell cultures were established from healthy corneas harvested from horses immediately following euthanasia and maintained using standard tissue culture protocols. To determine the effects of PDGF-BB, EGF, TGF-...
Bermúdez CS, Zaldívar AY, Spolidorio MG, Moraes-Filho J, Miranda RJ, Caballero CM, Mendoza Y, Labruna MB.The present research evaluated the presence of Rickettsia spp. on ectoparasites of horses and dogs (using PCR techniques), and their sera (using immunofluorescence assay) in El Valle de Antón town in Panama. A total of 20 horses and 20 dogs were sampled, finding four species of ectoparasites on dogs (the ticks Rhipicephalus sanguineus, Amblyomma ovale, Amblyomma oblongoguttatum, and the flea Ctenocephalides felis), and two tick species on horses (Amblyomma cajennense and Dermacentor nitens). DNA of Rickettsia amblyommii was found in pools of A. cajennense, D. nitens, and R. sanguineus, while ...
Tomlinson JE, Tennant BC, Struzyna A, Mrad D, Browne N, Whelchel D, Johnson PJ, Jamieson C, Löhr CV, Bildfell R, McKenzie EC, Laverack M, Renshaw RW....A novel equine parvovirus (EqPV-H) was recently discovered in the equine liver with Theiler's disease. Objective: To determine the prevalence of EqPV-H infection in naturally occurring Theiler's disease cases and in-contact horses in the absence of historical equine biologic product administration. Methods: Ten cases of Theiler's disease from 6 separate properties were included in the study, based on the criteria of acute onset of clinical signs of liver failure with laboratory or histopathologic findings characteristic of Theiler's disease and no history of receiving an equine biologic produc...
Saito S, Ugai H, Sawai K, Yamamoto Y, Minamihashi A, Kurosaka K, Kobayashi Y, Murata T, Obata Y, Yokoyama K.Embryonic stem (ES) cells are pluripotent cells with the potential capacity to generate any type of cell. We describe here the isolation of pluripotent ES-like cells from equine blastocysts that have been frozen and thawed. Our two lines of ES-like cells (E-1 and E-2) appear to maintain a normal diploid karyotype indefinitely in culture in vitro and to express markers that are characteristic of ES cells from mice, namely, alkaline phosphatase, stage-specific embryonic antigen-1, STAT-3 and Oct 4. After culture of equine ES-like cells in vitro for more than 17 passages, some ES-like cells diffe...
Cuny C, Witte W.MRSA infections in equine clinics were reported from Northern America, Europe, Australia, and Japan. The majority of nosocomial infections in horses is obviously associated with particular MRSA clonal lineages. As already observed for epidemic MRSA in human hospitals more than 10 years ago, a dynamics of MRSA clonal lineages is also observed in European equine clinics: clonal lineages belonging to clonal complex (CC) 8 are on the retreat whereas MRSA attributed to CC398 become increasingly prevalent. The majority of CC398 isolates belong to a subpopulation which is particularly associated with...
Harvey AM, Beausoleil NJ, Ramp D, Mellor DJ.Knowledge of the welfare status of wild animals is vital for informing debates about the ways in which we interact with wild animals and their habitats. Currently, there is no published information about how to scientifically assess the welfare of free-roaming wild animals during their normal day-to-day lives. Using free-roaming horses as an example, we describe a ten-stage protocol for systematically and scientifically assessing the welfare of individual non-captive wild animals. The protocol starts by emphasising the importance of readers having an understanding of animal welfare in a conser...
Nemoto M, Oue Y, Morita Y, Kanno T, Kinoshita Y, Niwa H, Ueno T, Katayama Y, Bannai H, Tsujimura K, Yamanaka T, Kondo T.Recently, outbreaks associated with equine coronavirus (ECoV) have occurred in Japan and the United States. While ECoV is likely to be pathogenic to horses, it has not been shown that experimental inoculation of horses with ECoV produces clinical signs of disease. In this study, we inoculated three Japanese draft horses with an ECoV-positive diarrheic fecal sample to confirm infection after inoculation and to investigate the clinical course and virus shedding patterns of ECoV. Virus neutralization tests showed that all three horses became infected with ECoV. Two of the three horses developed c...
Sharma M, Nunez-Garcia J, Kearns AM, Doumith M, Butaye PR, Argudín MA, Lahuerta-Marin A, Pichon B, AbuOun M, Rogers J, Ellis RJ, Teale C, Anjum MF.In recent years, there has been an increase in the number of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) clonal complex (CC) 398 recovered from S. aureus isolated animals in the UK. To determine possible origins of 12 LA-MRSA CC398 isolates collected after screening more than a thousand S. aureus animal isolates from the UK between 2013 and 2015, whole genome sequences (WGS) of CC398 European, including UK, and non-European isolates from diverse animal hosts were compared. Phylogenetic reconstruction applied to WGS data to assess genetic relatedness of all 89 iso...
Chambers TM, Quinlivan M, Sturgill T, Cullinane A, Horohov DW, Zamarin D, Arkins S, García-Sastre A, Palese P.Three previously described NS1 mutant equine influenza viruses encoding carboxy-terminally truncated NS1 proteins are impaired in their ability to inhibit type I IFN production in vitro and are replication attenuated, and thus are candidates for use as a modified live influenza virus vaccine in the horse. Objective: One or more of these mutant viruses is safe when administered to horses, and recipient horses when challenged with wild-type influenza have reduced physiological and virological correlates of disease. Methods: Vaccination and challenge studies were done in horses, with measurement ...
Crisman MV, Scarratt WK, Zimmerman KL.Activation of the host response to infection, the "acute-phase response," is a highly organized physiologic reaction that includes changes in concentrations of plasma acute-phase proteins (APPs). The APPs are increasingly being used as markers for prognosis and monitoring response to therapy along with general determinants of equine health. Use of APPs in veterinary medicine is becoming more widespread as more commercial diagnostic kits are being validated. This article reviews the salient features of APPs and examines their current application and potential utility in equine inflammatory diso...
Moreau MM, Eades SC, Reinemeyer CR, Fugaro MN, Onishi JC.In the equine carbohydrate overload model of acute laminitis, disease progression is associated with changes in bacteria found in the cecum. To date, research has focused on changes in specific Gram-positive bacteria in this portion of the intestinal tract. Metagenomic methods are now available making it possible to interrogate microbial communities using animal protocols that sufficiently power a study. In this study, the microbiota in cecal fluid collected from control, non-laminitic horses (n=8) and from horses with early-stage acute laminitis induced with either oligofructan (n=6) or corns...
Nielsen MK, Peterson DS, Monrad J, Thamsborg SM, Olsen SN, Kaplan RM.Strongylus vulgaris is an important strongyle nematode with high pathogenic potential infecting horses world-wide. Several decades of intensive anthelmintic use has virtually eliminated clinical disease caused by S. vulgaris, but has also caused high levels of anthelmintic resistance in equine small strongyle (cyathostomin) nematodes. Recommendations aimed at limiting the development of anthelmintic resistance by reducing treatment intensity raises a simultaneous demand for reliable and accurate diagnostic tools for detecting important parasitic pathogens. Presently, the only means available t...
Christoffersen M, Woodward E, Bojesen AM, Jacobsen S, Petersen MR, Troedsson MH, Lehn-Jensen H.The objective of the study was to evaluate the gene expression of inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, tumor necrosis factor [TNF]-α, IL-1 receptor antagonist [ra] and serum amyloid A (SAA) in endometrial tissue and circulating leukocytes in response to uterine inoculation of 105 colony forming units (CFU) Escherichia coli in mares. Before inoculation, mares were classified as resistant or susceptible to persistent endometritis based on their uterine inflammatory response to infusion of 109 killed spermatozoa and histological assessment of the endometrial quality. ...
