Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Pereira LO, DE Souza AF, Spagnolo JD, Yamada ALM, Salgado DMRA, DE Zoppa ALDV.Osteoarthritis (OA) is a prevalent condition in horses, leading to changes in trabecular bone structure and radiographic texture. Although fractal dimension (FD) and lacunarity have been applied to quantify these changes in humans, their application in horses remains nascent. This study evaluated the use of FD, bone area fraction (BA/TA), and lacunarity in quantifying trabecular bone differences in the proximal phalanx (P1) in 50 radiographic examinations of equine metacarpophalangeal joints with varying OA degrees. In the dorsopalmar view, regions of interest were defined in the trabecular bo...
Sobral GG, Neto OCG, Lima TC, Carneiro GF.Providing plasma with immunoglobulins is essential for the health of foals with failure of passive transfer of immunity. The use of lyophilized plasma (LP) offers a simple and affordable option in terms of transportation and storage. This study aimed to measure the concentrations of immunoglobulin G (IgG), total protein (TP), and total solids (TS) in fresh equine plasma before and after lyophilization. Plasma was collected from six healthy male horses. The samples underwent freeze-drying and were reconstituted in deionized water to their original volume. The concentrations of IgG in both fresh...
Meyer C, Gabriel F, Schrum K, Hollis M, Short M, Gould S.Airbag vests (AV) are increasingly popular in equestrian sports. The efficacy of AV in protecting against serious injury has not been adequately analyzed, nor have product testing standards been established. This study provides an overview of current research to understand AV efficacy and future areas of improvement. A systematic review applying the PRISMA framework, NIH Study Quality Assessment, and CEBM Level of Evidence was conducted. Employing variations of "equestrian sport," "powered two-wheeled vehicle," "thoracic injury," "chest deflection," "airbag vest," and "safety vest," 18 article...
Muñoz-Prieto A, Llamas-Amor E, Cerón JJ, Hansen S.Equine gastric ulcer syndrome (EGUS) is a prevalent condition in horses, affecting up to 93% of racehorses. Comprising the equine squamous gastric disease (ESGD) and the equine glandular gastric disease (EGGD), EGUS poses significant health challenges. Saliva, a non-invasive and easily obtainable sample, is increasingly recognized for its potential as a source of biomarkers in horses. This study investigates changes in saliva analytes using automated assays before and after EGUS treatment, aiming to identify biomarkers indicative of treatment success or failure. A total of 28 horses diagnosed ...
Uchida T, Kisugi T, Ishii H, Yamada M, Kinoshita K, Leung GN.To uphold the integrity of horseracing and equestrian sports, it is critical for an equine doping control laboratory to develop a comprehensive screening method to cover a wide range of target substances at the required detection levels in equine urine. Methods: The procedure involved the enzymatic hydrolysis of 3 mL urine samples followed by solid-phase extraction using HF Bond Elut C18 cartridge. The resulting extracts were then separated on a C18 reversed-phase column and analyzed using liquid chromatography/high-resolution mass spectrometry (LC/HRMS) in both electrospray ionization positiv...
Lima AE, Piñeros DDV, Alibrando BB, Bittar MJ, de Souza AF, Mendes RP, de Freitas SH, Bernardino T, Corrêa RR.The anatomical variations of the maxillary septum and the septal bullae can generate challenges during the interpretation of radiographs of the horses' heads and make it difficult to accurately identify the sites affected in sinus disorders. The description of the radiographic appearance of these structures is currently scarce in the scientific literature. This work aims to describe the anatomical and radiographic characteristics of the maxillary septum and maxillary septal bullae in horses. Six chemically preserved equine cadaver heads were used which, after being submitted to the maxillary o...
Pimenta J, Prada J, Pires I, Cotovio M.Sarcoids and squamous cell carcinomas (SCCs) are the most concerning equine oncological diseases. Both tumors are challenging to manage due to their invasive behavior and high prevalence of recurrences. Furthermore, SCCs have a propensity to metastasize. Programed cell-death ligand 1 (PD-L1) has been one of the main therapeutic targets for immunotherapy in various human tumors. PD-L1 research in equine tumors is scarce and more efforts are necessary to understand the potential of this biomarker as a therapeutical target. Unassigned: Evaluate the immunohistochemical expression of PD-L1 in equin...
Byrne CA, Voute LC, Marshall JF.Agreement between experienced observers for assessment of pathology and assessment confidence are poorly documented for magnetic resonance imaging (MRI) of the equine foot. Objective: To report interobserver agreement for pathology assessment and observer confidence for key anatomical structures of the equine foot during MRI. Methods: Exploratory clinical study. Methods: Ten experienced observers (diploma or associate level) assessed 15 equine foot MRI studies acquired from clinical databases of 3 MRI systems. Observers graded pathology in seven key anatomical structures (Grade 1: no pathology...
Medina B AL, Faleiros RR, Martínez A JR.Equine Gastric Ulcer Syndrome (EGUS) occurs with variable prevalence in horses, donkeys, and mules. Due to the particularities of the mucous membranes, the syndrome is made up of Squamous Gastric Disease (ESGD) and Glandular Gastric Disease (EGGD). Given the multifactorial nature and multiple classification systems of the syndrome, significant differences have been reported between prevalence studies performed ante mortem, which are even more remarkable when compared with postmortem evaluations. This study aimed to determine the presence and grade of squamous gastric disease in horses, donkeys...
Nunes MM, Gurgel JRC, Munhoz ML, de Giuli V, Carneiro GF, Miragaya MH, Gallelli MF, Guimaraes JD.The aim of this study was to assess the effect of lyophilized freezing extenders, which can be stored at room temperature, on stallion post-thaw sperm total motility (TM). Ejaculates of 28 stallions were frozen with four different extenders: two commercial freezing extenders offered worldwide and two novel lyophilized extenders (STAR and MX3), and two different cryopreservation protocols (CP1 with an equilibration period of 20 min. and CP2 with an equilibration period of 60 min.). The TM was assessed after thaw. Mean TM did not show significant differences between cryopreservation protocols wi...
Pontaema T, Pongthaisong P, Kenchaiwong W, Chompoosan C, Lerdweeraphon W.Vasovagal tonus index (VVTI) serves as a straightforward assessment tool for autonomic function during both physiological and pathological conditions, including pregnancy, in horses. Obtaining VVTI through a modified base apex lead system could be a practical and comfortable solution. In this study, we assessed VVTI in horses with respect to training status and electrocardiographic measurements utilizing a novel modified base apex lead technique. Unassigned: A total of 12 Thai native crossbred horses and 12 Arabian horses, all free of cardiac abnormalities, were enrolled in the study. Animals ...
Dyson S, Phillips K, Zheng S, Aleman M.There is controversy about the clinical relevance of congenital variants of the ventral laminae of the sixth (C6) and seventh (C7) cervical vertebrae and their relationship with other radiological abnormalities. Objective: To document the prevalence of congenital variants of C6 and C7 and that of other radiological abnormalities from C6 to the second thoracic vertebra (T2). Methods: Cross-sectional. Methods: The study included Warmblood horses ≥3 years of age undergoing clinical assessment at two referral institutions: 127 control horses and 96 cases (neurologic, neck pain or stiffness, or...
Zaghloul IY, Bedenice D, Ceresia ML, Jones PH, Sanchez-Londono A, Lobo MN, Böhlke M, Paradis MR.To evaluate the effects of aging on phenylbutazone (PBZ) disposition in older horses (≥ 25 years old) compared to young adults (4 to 10 years old) by characterizing the pharmacokinetic profile of PBZ and its active metabolite, oxyphenbutazone (OPBZ), following a 2.2-mg/kg dose, IV. We hypothesized that the disposition of PBZ will be affected by age. Methods: 16 healthy horses (8 young adults aged 4 to 10 years and 8 geriatric horses ≥ 25 years old). Methods: Horses were administered a single 2.2-mg/kg PBZ dose, IV. Plasma samples were collected at designated time points and frozen at -80 ...
Iranmanesh M, Sato AF, Tenney W, Brinker EJ, Cortez K, Mazan M.A 1-year-old Miniature Horse filly was presented for chronic lethargy and hyporexia. Elevated liver enzymes, bile acids, and ammonia were noted on bloodwork. The primary differential diagnosis was a portosystemic shunt (PSS). Three-phase computed tomographic angiography findings were consistent with a transhepatic portosystemic shunt. Percutaneous liver biopsy confirmed severe diffuse hepatic changes, most likely due to chronic pyrrolizidine alkaloid toxicosis, and medical management was elected. Based on an extensive literature review, this is the first report of a transhepatic portosystemic ...
Bishop RC, Migliorisi A, Holmes JR, Kemper AM, Band M, Austin S, Aldridge B, Wilkins PA.Understanding normal microbial populations within areas of the respiratory tract is essential, as variable regional conditions create different niches for microbial flora, and proliferation of commensal microbes likely contributes to clinical respiratory disease. The objective was to describe microbial population variability between respiratory tract locations in healthy horses. Samples were collected from four healthy adult horses by nasopharyngeal lavage (NPL), transtracheal aspirate (TTA), and bronchoalveolar lavage (BAL) of six distinct regions within the lung. Full-length 16S ribosomal DN...
Germann JA, O'Sullivan TL, Greer AL, Spence KL.Disease outbreaks present a significant challenge to horse health and welfare and the economic stability of horse industries internationally. This is a particular concern in Ontario, Canada, where there have been frequent outbreaks of respiratory infectious diseases among horses. Despite these risks, there has been limited research on whether Ontario horse owners engage in biosecurity measures sufficient to mitigate risk of equine diseases, and whether current events such as the COVID-19 pandemic influence attitudes towards equine biosecurity practices. Objective: To explore Ontario horse owne...
Baudisch N, Singer E, Jensen KC, Eichler F, Meyer HJ, Lischer C, Ehrle A.Surgical treatment options for horses with overriding dorsal spinous processes include interspinous ligament desmotomy and partial spinous process ostectomy. The impact of spinal surgery on the three-dimensional biomechanics of the equine thoracolumbar spine and the epaxial musculature is unclear. Objective: To investigate the influence of interspinous ligament desmotomy and cranial wedge ostectomy on the biomechanics of the equine thoracolumbar spine and the paraspinal Musculi multifidi. Methods: Ex-vivo experiments. Methods: Twelve equine thoracolumbar spine specimens were mounted in a custo...
Mazan MR, Simotas C, Coons T, Barrow B, Bedenice D, Minuto J, Wendell K, Deveney EF.Pulmonary function testing is critical to the diagnosis of equine asthma (EA), an important cause of respiratory disease in the horse, but its clinical use has remained elusive, unfortunately, due to the complexity of reference methods, esophageal balloon/pneumotachography (EBP), and forced oscillatory mechanics (FOM), so we sought a noninvasive, portable method for use in horses through rapid interruption of airflow for equilibration of alveolar pressure with proximal airway pressure, termed flow interruption (FI). Resistance (RINT) was computed as the relationship between the change in press...
Carey KJ, Smith I, Barr J, Caruso S, Au GG, Hartley CA, Bailey KE, Perriam W, Broder CC, Gilkerson JR.Hendra virus (HeV) is lethal to horses and a zoonotic threat to humans in Australia, causing severe neurological and/or respiratory disease with high mortality. An equine vaccine has been available since 2012. Foals acquire antibodies from their dams by ingesting colostrum after parturition, therefore it is assumed that foals of mares vaccinated against HeV will have passive HeV antibodies circulating during the first several months of life until they are actively vaccinated. However, no studies have yet examined passive or active immunity against HeV in foals. Here, we investigated anti-HeV a...
Oliveira MC, de Lima MT, Trindade PHE, Luna SPL.To evaluate if students without training assess pain similarly to an expert, and to compare indications for analgesic intervention based on student opinions versus scale scoring. Methods: Prospective, blind, randomized, cross-sectional study. Methods: Video recordings of a bull, horse, cat, pig and sheep. Methods: First-year veterinary medicine students assessed one video of a horse (n = 44) and one video of a bull (n = 39). Third-year veterinary medicine students assessed one video of a cat (n = 23) and one video of a pig (n = 21). Fourth-year animal science students (n = 16) assessed on...
Ho HSM, Farrington AF, Bond AJ, Ho ENM, Wong WT.Estra-4,9-diene-3,17-dione (dienedione) is an anabolic-androgenic steroid (AAS) available on the market as a dietary supplement for bodybuilding. It is prohibited in both human and equine sports due to its potential performance-enhancing effect. With the rare presence of the 4,9-diene configuration in endogenous steroids, dienedione has been considered as a synthetic AAS. Nevertheless, the reoccurring detection of dienedione in entire male horse urine samples led to the investigation of its possible endogenous nature in horses, and its endogenous nature in entire male horses has been recently ...
Lindinger H, Wehrend A.In horses, parturition is characterized by the fact that any delays may rapidly result in the death of the foal. Therefore, birth monitoring and the rapid detection of dystocia are of great importance. For this purpose, the differentiation between behavior associated with physiological parturition and activities related to difficult parturition is important. The aim of this publication is to present the physiological behavior of mares during parturition on the basis of a literature review. The behavior of mares in the opening phase of parturition is highly individual. In general, it is charact...
Skierbiszewska K, Szałaj U, Turek B, Sych O, Jasiński T, Łojkowski W, Domino M.In equine medicine, assisted bone regeneration, including use of biomaterial substitutes like hydroxyapatite (HAP), is crucial for addressing bone defects. To follow-up on the outcome of HAP-based bone defect treatment, the advancement in quantified diagnostic imaging protocols is needed. This study aimed to quantify and compare the radiological properties of the HAP graft and natural equine bone using Magnetic Resonance (MR) and Computed Tomography (CT), both Single (SECT) and Dual Energy (DECT). SECT and DECT, allow for the differentiation of three HAP grain sizes, by progressive increase in...
Burrell KL, Burford JH, England GCW, Freeman SL.The survival of horses diagnosed with critical colic (requiring referral or euthanasia) relies on rapid and effective decision-making by the owner and veterinary practitioner. Objective: To explore UK horse owners' and veterinary practitioners' experiences of decision-making for critical cases of equine colic. Methods: Qualitative study using a phenomenological approach. Methods: Individual, semi-structured telephone interviews were conducted with 14 horse owners and 13 veterinary practitioners (vets) who had experienced a critical decision (referral or euthanasia) for a horse with colic. A pu...
Höglund N, Rossi H, Javela HM, Oikari S, Nieminen P, Mustonen AM, Airas N, Kärjä V, Mykkänen A.Equine asthma (EA) is a chronic lower airway inflammation that leads to structural and functional changes. Hyaluronic acid (HA) has crucial functions in the extracellular matrix homeostasis and inflammatory mediator activity. HA concentration in the lungs increases in several human airway diseases. However, its associations with naturally occurring EA and airway remodelling have not been previously studied. Our aim was to investigate the association of equine neutrophilic airway inflammation (NAI) severity, airway remodelling, and HA concentration in horses with naturally occurring EA. We hypo...
Wong ASY, Yuen BP, Wong COL, Kong FK, So YM, Kwok WH, Brooks L, Wan TSM, Ho EN.Bisphosphonates and myo-inositol trispyrophosphate (ITPP) are two classes of difficult-to-detect polar drugs that are prohibited under the rules of racing. ITPP is a drug capable of increasing the amount of oxygen in hypoxic tissues, and studies have shown that administration of ITPP increases the maximal exercise capacity in mice. The properties of ITPP make it an ideal candidate as a doping agent to enhance performance in racehorses. In recent years, ITPP had indeed been detected in racehorses and confiscated items. As for bisphosphonates, it is especially critical to control their use as si...
Dos Santos Rosse N, Reis ECC.The resistivity index (RI) evaluates haemodynamic based on arterial resistance. Alterations in renal blood flow are important for the early detection of kidney damage, as perfusion might be one of the first affected aspects. Objective: To retrieve published studies on equine renal RI to develop a standardised method of renal ultrasonographic examination and to evaluate the current reference range for the renal RI in horses. Methods: Systematic review. Methods: An electronic search in Science Direct, PubMed, Scopus and Web of Science databases was performed in February 2023 using the terms 'RI'...
Means K, Hayden L, Kramer J, McCracken MJ, Reed SK, Wilson DA, Keegan KG.Compensatory vertical head and pelvis movement asymmetry may occur in trotting horses with a primary cause of lameness in one end of the body due to the weight shifting between limbs, leading to apparent combined forelimb and hindlimb lameness (CFHL). Little is known about CFHL patterns observed with body-mounted inertial sensors (BMIS) and regardless of their underlying mechanisms, compensatory and secondary lameness may complicate the definitive identification of the primary causes of lameness. Objective: Determine associations between vertical pelvic movement asymmetry and location of prima...
Luick ML, Khouzam NA, Pérez-Nogués M.To establish racing prognosis in Thoroughbred yearlings with proximal sagittal ridge osteochondral lesions and compare them to dorsoproximal and palmar/plantar first phalanx osteochondral lesions. Methods: A total of 47 horses had proximal sagittal ridge lesions, 34 had palmar/plantar first phalanx lesions, and 115 had dorsoproximal first phalanx lesions. Methods: Retrospective case series. Methods: Medical records of Thoroughbred yearling racing prospects treated arthroscopically for fetlock osteochondral lesions were reviewed. Data were collected from a public database, including the ability...
This study presents the validation of two recently described pain scales, the Equine Utrecht University Scale for Composite Pain Assessment (EQUUS-COMPASS) and the Equine Utrecht University Scale for Facial Assessment of Pain (EQUUS-FAP), in horses with acute colic. A follow-up cohort study of 46 adult horses (n = 23 with acute colic; n = 23 healthy control horses) was performed for validation and refinement of the constructed scales. Both pain scales showed statistically significant differences between horses with colic and healthy control horses, and between horses with colic that co...
Carter RA, McCutcheon LJ, Valle E, Meilahn EN, Geor RJ.To determine effects of exercise training without dietary restriction on adiposity, basal hormone and lipid concentrations and glucose and insulin dynamics in overweight or obese, insulin-resistant horses. Methods: 12 overweight or obese (body condition score > or = 7), insulin-resistant (insulin sensitivity < or = 1.2 x 10(-4) L/min/mU) geldings. Methods: 4 horses remained sedentary, and 8 horses were exercised for 4 weeks at low intensity and 4 weeks at higher intensity, followed by 2 weeks of detraining. Prior to and after each training period, frequently sampled IV glucose tolerance ...
Álvarez-Narváez S, Berghaus LJ, Morris ERA, Willingham-Lane JM, Slovis NM, Giguere S, Cohen ND.The practice of prophylactic administration of a macrolide antimicrobial with rifampin (MaR) to apparently healthy foals with pulmonary lesions identified by thoracic ultrasonography (i.e., subclinically pneumonic foals) is common in the United States. The practice has been associated epidemiologically with emergence of R. equi resistant to MaR. Here, we report direct evidence of multi-drug resistance among foals treated with MaR. In silico and in vitro analysis of the fecal microbiome and resistome of 38 subclinically pneumonic foals treated with either MaR (n = 19) or gallium maltolate (...
Tadros EM, Fowlie JG, Refsal KR, Marteniuk J, Schott HC.Hyperinsulinaemia is the suspected component of insulin dysregulation having the strongest association with laminitis and occurs variably in equids with pituitary pars intermedia dysfunction (PPID). Objective: We hypothesised that magnitude of hyperinsulinaemia correlates with laminitis severity in PPID-affected equids. Furthermore, we hypothesised that owners can be unaware of chronic endocrinopathic laminitis. Methods: Cross-sectional study. Methods: Serum insulin concentrations, owner-reported laminitis history and radiographic evidence of laminitis were determined in 38 client-owned horses...
O'Callaghan DJ, Hyde JM, Gentry GA, Randall CC.Infection of exponential-phase suspension cultures of mouse fibroblast cells (L-M) with equine abortion virus (EAV) resulted in inhibition of cell growth and marked alterations in host metabolic processes. The synthesis of deoxyribonucleic acid (DNA) and ribonucleic acid was inhibited within 4 hr after infection and was suppressed by more than 90% by the time of maximal virus replication (14 to 18 hr). The overall rate of protein synthesis, however, was similar in uninfected and virus-producing cells as determined by measurements of net protein and isotope incorporation. The time course of vir...
Cleton NB, van Maanen K, Bergervoet SA, Bon N, Beck C, Godeke GJ, Lecollinet S, Bowen R, Lelli D, Nowotny N, Koopmans MPG, Reusken CBEM.The genus Flavivirus in the family Flaviviridae includes some of the most important examples of emerging zoonotic arboviruses that are rapidly spreading across the globe. Japanese encephalitis virus (JEV), West Nile virus (WNV), St. Louis encephalitis virus (SLEV) and Usutu virus (USUV) are mosquito-borne members of the JEV serological group. Although most infections in humans are asymptomatic or present with mild flu-like symptoms, clinical manifestations of JEV, WNV, SLEV, USUV and tick-borne encephalitis virus (TBEV) can include severe neurological disease and death. In horses, infection wi...
Li X, Shi F, Gong L, Hang B, Li D, Chi L.Colla corii asini (CCA) is a protein-based traditional Chinese medicine made from donkey skins. Because it has the ability to nourish blood, its demand is increasing rapidly. The shortage of donkey skins increases the risk of the adulteration of CCA products with other animal skins. To ensure the drug efficacy and safety of CCA products, a proteomics technique was applied to reveal proteins in the skins of donkey, horse, cattle, and pig. Species-specific peptides for each animal species were predicted using bioinformatics, and their presence in the skins and gelatin samples was examined by nan...
Payne SL, Rushlow K, Dhruva BR, Issel CJ, Montelaro RC.Previous characterizations of equine infectious anemia virus (EIAV) glycoprotein variation by DNA sequence analysis and epitope mapping using monoclonal antibodies (MAbs) have revealed the presence of conserved and variable regions within the EIAV env gene. To extend these studies, fragments of the EIAV envelope proteins gp90 and gp45 were expressed in Escherichia coli and used in Western blot analysis with a diverse panel of equine immune sera to identify antigenic segments. All sera from EIAV-infected animals reacted with the carboxyl terminal portion of gp90 and the amino terminal portion o...
Olstad K, Ytrehus B, Ekman S, Carlson CS, Dolvik NI.Material available for research into osteochondrosis (OC) in humans tends to represent chronic lesions. Comparative studies of early lesions in young animals are, therefore, important in clarifying the pathogenesis of OC in humans. Recent studies in pigs provide strong evidence that lesions of articular OC are associated with a focal failure in the cartilage canal vascular supply to epiphyseal growth cartilage (articular-epiphyseal cartilage complex excluding the articular cartilage). The purpose of the present study was to examine histological sections from a specific predilection site for ar...
Fazio E, Medica P, Aronica V, Grasso L, Ferlazzo A.Since transport evokes physiological adjustments that include endocrine responses, the objective of this study was to examine the responses of circulating beta-endorphin, adrenocorticotrophic hormone (ACTH) and cortisol levels to transport stress in stallions. Methods: Forty-two healthy Thoroughbred and crossbred stallions were studied before and after road transport over distances of 100, 200 and 300 km. Blood samples were collected from the jugular vein: first in a single box immediately before loading (pre-samples), then immediately after transport and unloading on arrival at the breeding s...
Monteiro SO, Lepage OM, Theoret CL.To evaluate the effect of platelet-rich plasma on wounds on the distal aspect of the forelimb in horses. Methods: 6 mixed-breed 10- to 15-year-old mares. Methods: 3 wounds were created on metacarpal regions in each of 6 horses (n = 36 wounds total). Eighteen wounds were treated with platelet-rich plasma and bandaged, whereas 18 control wounds were similarly bandaged with no prior topical treatment. Decrease in wound surface area and the required number of excisions of exuberant granulation tissue were recorded until complete healing. Tissue specimens were taken from wounds at 1 week for histol...
Figueiredo MD, Vandenplas ML, Hurley DJ, Moore JN.Our understanding of the innate immune response in the horse has been limited by a lack of definitive data concerning cell signaling in response to microbial products. Toll-like receptors (TLRs) recognize conserved molecular motifs of microbes and elicit immune responses through their coupling with intracellular adaptor molecules, particularly MyD88 and TRIF. To provide a more definitive characterization of TLR signaling in the horse, the objectives of this study were to: (1) characterize the responses of equine monocytes to TLR ligands that signal through MyD88, TRIF or both in other species,...
De Schauwer C, Van de Walle GR, Van Soom A, Meyer E.In the past decade, mesenchymal stem cells (MSC) have received much attention in equine veterinary medicine. The first therapeutic use of equine MSC was reported in 2003. Since then, the clinical application of MSC has been exploding with thousands of horses now treated worldwide. At present, MSC are mainly used in veterinary medicine to treat musculoskeletal diseases based on their ability to differentiate into various tissues of mesodermal origin. This is in marked contrast to human medicine, where MSC therapies are primarily focused on immune-mediated, inflammatory, and ischemic diseases. I...
Fernandez NJ, Hecker KG, Gilroy CV, Warren AL, Léguillette R.Reliable enumeration of mast cells and eosinophils in equine bronchoalveolar lavage (BAL) fluid is important because small increases in the percentages of these cells support the clinical diagnosis of inflammatory airway disease (IAD). Increases in BAL neutrophils also occur with IAD but are not specific due to overlap between IAD and recurrent airway obstruction (RAO). Objective: The objectives of this study were to evaluate the reliability of a standard 400-cell leukocyte differential count and an alternate method evaluating 5 microscopic fields at 500× magnification in equine BAL fluid cyt...
Moore JN, Vandenplas ML.Some veterinarians describe particularly sick horses or neonatal foals as being endotoxemic, whereas others refer to the same animals as having the systemic inflammatory response syndrome. This article reviews the basis for the use of each of these terms in equine practice, and highlights the mechanisms underlying the response of the horse's innate immune system to key structural components of the microorganisms that initiate these conditions, including how some of those responses differ from other species. Current approaches used to treat horses with these conditions are summarized, and cauti...
Hong CB, Donahue JM, Giles RC, Petrites-Murphy MB, Poonacha KB, Roberts AW, Smith BJ, Tramontin RR, Tuttle PA, Swerczek TW.Pathologic and microbiologic examinations were performed on 1,211 aborted equine fetuses, stillborn foals, and placentas from premature foals in central Kentucky during the 1988 and 1989 foaling seasons to determine the causes of reproductive loss in the mare. Placentitis (19.4%) and dystocia-perinatal asphyxia (19.5%) were the 2 most important causes of equine reproductive loss. The other causes (in decreasing order) were contracted foal syndrome and other congenital anomalies (8.5%), twinning (6.1%), improper separation of placenta (4.7%), torsion of umbilical cord (4.5%), placental edema (4...
Lyons ET, Tolliver SC, Ionita M, Collins SS.Horse foals on five farms in Central Kentucky were used in field studies in 2007 evaluating activity of paste formulations of four compounds (fenbendazole-FBZ, ivermectin-IVM, oxibendazole-OBZ, and pyrantel pamoate-PRT) against internal parasites with emphasis on ascarids (Parascaris equorum). It has been well established the last few years that there is widespread resistance of P. equorum to ivermectin. The main purpose of the present research was to obtain current data on ascaridicidal activity of FBZ, OBZ, and PRT; also, to acquire further information on ascarid resistance to ivermectin. Ad...
Rios JJ, Fleming JG, Bryant UK, Carter CN, Huber JC, Long MT, Spencer TE, Adelson DL.West Nile virus, first identified within the United States in 1999, has since spread across the continental states and infected birds, humans and domestic animals, resulting in numerous deaths. Previous studies in mice identified the Oas1b gene, a member of the OAS/RNASEL innate immune system, as a determining factor for resistance to West Nile virus (WNV) infection. A recent case-control association study described mutations of human OAS1 associated with clinical susceptibility to WNV infection. Similar studies in horses, a particularly susceptible species, have been lacking, in part, because...
It is currently unknown if the intrathecal administration of a high dose of allogeneic mesenchymal stem cells (MSCs) is safe, how MSCs migrate throughout the vertebral canal after intrathecal administration, and whether MSCs are able to home to a site of injury. The aims of the study were: 1) to evaluate the safety of intrathecal injection of 100 million allogeneic adipose-derived MSCs (ASCs); 2) to assess the distribution of ASCs after atlanto-occipital (AO) and lumbosacral (LS) injection in healthy horses; and 3) to determine if ASCs homed to the site of injury in neurologically diseased hor...
Hotham WE, Thompson C, Szu-Ting L, Henson FMD.Osteoarthritis (OA) in the horse is an economic and welfare issue and there are no current disease modifying drugs available. Stem cells have been suggested as a therapeutic intervention for OA, originally on the basis of their regenerative capacity. However, it is hypothesised that mesenchymal stem cells (MSC) exert their effects via paracrine factors including the production of extracellular vesicles that can themselves recapitulate the MSC effects in the joint. Objective: To isolate extracellular vesicles from bone marrow MSC and investigate their anti-inflammatory effects on chondrocytes. ...
Menendez MI, Clark DJ, Carlton M, Flanigan DC, Jia G, Sammet S, Weisbrode SE, Knopp MV, Bertone AL.To evaluate healing of surgically created large osteochondral defects in a weight-bearing femoral condyle in response to delayed percutaneous direct injection of adenoviral (Ad) vectors containing coding regions for either human bone morphogenetic proteins 2 (BMP-2) or -6. Methods: Four 13mm diameter and 7mm depth circular osteochondral defects were drilled, 1/femoral condyle (n=20 defects in five ponies). At 2 weeks, Ad-BMP-2, Ad-BMP-6, Ad-green fluorescent protein (GFP), or saline was percutaneously injected into the central drill hole of the defect. Quantitative magnetic resonance imaging (...
Céleste C, Ionescu M, Robin Poole A, Laverty S.Although intraarticular (IA) corticosteroids are frequently used to treat joint disease, the effects of their repeated use on articular cartilage remains controversial. The aim of our study was to determine the effects of a clinically recommended dose of IA triamcinolone acetonide (TA), on synovial fluid (SF) biomarkers of cartilage metabolism. Ten adult horses, free of osteoarthritis (OA) in their radiocarpal joints, were studied. One radiocarpal joint of each horse was randomly chosen for treatment and the contralateral anatomically paired joint acted as the control. Aseptic arthrocentesis w...
Skedros JG, Mason MW, Nelson MC, Bloebaum RD.Functionally induced strains provide epigenetic signaling for bone modeling and remodeling activities. Strain gauge documentation of the equine third metacarpal reveals a neutral axis passing through the craniolateral cortex, resulting in a narrow band of cortex loaded predominantly in tension, with the remainder of the cortex experiencing a wide range of compression strain magnitudes that are maximal in the caudomedial cortex. This predictable strain pattern provides a model for examining the hypothesis that strain mode, magnitude, and strain energy density are potential correlates of compact...
Alhassan A, Govind Y, Tam NT, Thekisoe OM, Yokoyama N, Inoue N, Igarashi I.The sensitivity of LAMP, PCR and in vitro culture methods for the detection of Theileria equi and Babesia caballi was evaluated using tenfold serially diluted culture parasites. On day 1 post-culture, both T. equi and B. caballi parasites could only be observed at 1% parasite dilution from the in vitro culture method, whereas LAMP could detect up to 1 x 10(-3)% of both T. equi and B. caballi parasite dilutions, whilst PCR could detect 1 x 10(-3)% T. equi and 1 x 10(-1)% B. caballi parasite dilutions. On day 7 post-culture, the detection limit for T. equi and B. caballi in the in vitro culture ...
Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging problem in horses; however, the epidemiology of infection and colonization is poorly understood. This study evaluated factors associated with MRSA colonization at the time of admission to a veterinary teaching hospital. A case-control study evaluating historical factors was performed. Previous colonization of the horse, previous identification of colonized horses on the farm, antimicrobial administration within 30 days, admission to the neonatal intensive care unit, and admission to a service other than the surgical service were...
Siger L, Bowen RA, Karaca K, Murray MJ, Gordy PW, Loosmore SM, Audonnet JC, Nordgren RM, Minke JM.To determine the onset of immunity after IM administration of a single dose of a recombinant canarypox virus vaccine against West Nile virus (WNV) in horses in a blind challenge trial. Methods: 20 mixed-breed horses. Methods: Horses with no prior exposure to WNV were randomly assigned to 1 of 2 groups (10 horses/group). In 1 group, a recombinant canarypox virus vaccine against WNV was administered to each horse once (day 0). The other 10 control horses were untreated. On day 26, 9 treated and 10 control horses were challenged via the bites of mosquitoes (Aedes albopictus) infected with WNV. Cl...
Beg MA, Ginther OJ.The eminent event in follicle selection during a follicular wave in monovular species is diameter deviation, wherein one follicle continues to grow (developing dominant) and other follicles (subordinates) begin to regress. In cattle, the IGF system, oestradiol and LH receptors are involved in the intrafollicular events initiating deviation as indicated by the following: (1) concentrations of free IGF-I and oestradiol in the follicular fluid and number of LH receptors in the follicular wall increase more dramatically in the future dominant follicle than in the future subordinate follicles befor...
Battsetseg B, Lucero S, Xuan X, Claveria FG, Inoue N, Alhassan A, Kanno T, Igarashi I, Nagasawa H, Mikami T, Fujisaki K.The potential role of Boophilus microplus as a natural tick vector of Babesia equi and Babesia caballi in Brazilian horses was assessed using nested polymerase chain reaction (PCR)-based marker assay. B. equi merozoite-specific 218bp gene fragment was detected in almost 96% of horse blood samples, and 45.3-62.5% of females, eggs, larvae, and nymphs of B. microplus collected from 47 horses at Campo Grande in the State of Matto Grosso, Brazil. Except for the partially-fed female ticks, the B. caballi-specific 430bp gene fragment was amplified from horse blood samples, and all developmental stage...
Espinoza JR, Terashima A, Herrera-Velit P, Marcos LA.Fasciola hepatica is the causative agent of fasciolosis in Peru; the disease is an important public health problem by the high prevalence of the human infection affecting mainly children and a major veterinary problem by the high rates of infected livestock. The human disease is endemic in the Sierra and the Coast but sporadic in the Amazonia, and reported in 18 Departments, while the animal infection in 21 of 24 Departments of Peru. Transmission occurs in Andean rural populations engaged in agriculture, but recently an increasing number of people became infected in the cities. The epidemiolog...
