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.
Bramall LM, Hinnigan GJ, Wattam AD, Owen KR.This case report describes the successful hemithyroidectomy of the largest equine solid follicular adenoma described in the veterinary literature to date. A 19-year-old thoroughbred mare was referred to Oakhill Veterinary Centre for the surgical removal of a large, left-sided thyroid gland measuring 26cm in diameter. Pre-operative considerations, the hemithyroidectomy surgical technique as well as the intra- and post-operative complications encountered, are discussed. Following surgery the horse had no long-term complications and continues to thrive four and a half years post-operatively.
Donato GG, Necchi D, Gionechetti F, Ala U, Nebbia P, Robino P, Stella MC, Vandaele H, Pallavicini A, Nervo T.In the past, bacteria detected in the mare's uterus were generally interpreted as a sign of endometritis, since the uterus was considered a sterile environment. This assumption has been challenged by the introduction of culture-independent molecular techniques, particularly 16S rRNA amplicon sequencing, which have demonstrated that healthy mares harbor an endometrial microbiota. The aim of this study was to characterize the endometrial microbiota of healthy mares and to determine whether microbial composition differs between estrus and diestrus. Endometrial samples were collected from eleven h...
Kremer H, Bartling B.The nasal vestibule of numerous horses is pigmented. In the ventral part of the nasal vestibule, this pigmentation is often disturbed resulting in a clearly depigmented area. As nasal discharge passes this area, our study aimed at the practical quantification of the depigmented area in the nasal vestibule of horses and the analysis of its relation to nasal discharge and other parameters.This study included 74 horses (59 warmblood horses, 15 ponies) with pigmented nasal vestibule. When a depigmentation was found to be present in the ventral part, this area was photographed and quantified by use...
Toddy T, Ledbetter EC, Knickelbein KE.To describe the demographics and treatment outcomes of horses definitively diagnosed with epithelial or stromal immune-mediated keratitis (IMMK) by use of in vivo confocal microscopy (IVCM) and/or histopathology. Unassigned: Medical records of horses presented to the Cornell University Equine Hospital definitively diagnosed with epithelial or stromal IMMK with IVCM and/or histopathology between 2020 and 2024 were reviewed. Patient signalment, affected eye(s), diagnostics, treatments, and outcomes were assessed. Unassigned: 22 horses met the inclusion criteria. The mean age was 16.9 years (SD, ...
Starrett A, Arnold CE, Burr A, Sarturi JO, Leatherwood JL, Pilla R, Awosile BB, Chaffin MK.To quantify gastrointestinal motility at 3 anatomic locations of the large colon in healthy horses fed 2 diets. Unassigned: 12 American Quarter Horses were enrolled in a prospective crossover study. Horses received either a complete pelleted diet fed at 1.35% body weight (BW) per day or Coastal Bermudagrass hay fed at 2% BW with 0.5% to 0.7% BW of complete pelleted feed. Each diet was fed for 13 days prior to motility assessment. Two ultrasonographers recorded the frequency of contractions at the sternal flexure of the large colon, left ventral colon, and cecum for 4 consecutive, 1-minute peri...
Schmidt S, Swagemakers JH, le Jeune SS.The cervical vertebral column in horses plays a crucial role in movement, posture, and performance and disorders affecting it can cause pain, ataxia, or lameness. This review discusses major acquired (traumatic, infectious, neoplastic) and degenerative (osteoarthritis, foraminal stenosis, intervertebral disc disease) conditions. Acquired lesions often arise from trauma, bacterial infection, or neoplasia, with clinical signs ranging from neck pain to neurologic deficits. Degenerative disorders, particularly osteoarthritis of articular process joints, are common in the caudal cervical spine and ...
Lutvikadic I, Preldzic D, Floriano D, Hopster K.Pulse pressure (PP) reflects ventricular stroke volume and arterial compliance, but its utility as a marker of cardiac disease in animals is not well established. This study evaluated the association between PP and echocardiographically confirmed cardiac abnormalities in dogs and horses and assessed its potential in pre-anesthetic evaluation. Clinical and echocardiography examination of 20 dogs and 20 horses was sufficient for inter-group comparisons and assignments to a Cardiac group (echocardiographically confirmed cardiac disease) or a Control group (healthy animals). Non-invasive oscillome...
Henderson AR, Valverde A, Côté N, Sanchez A, Arroyo LG, Gu Y, Johnson R.To compare cardiopulmonary variables and recovery scores in isoflurane-anesthetized horses undergoing arthroscopy using two different intravenous (IV) lidocaine constant rate infusions (CRIs; 50 or 100 μg kg minute) under intermittent positive pressure ventilation (IPPV) or spontaneous ventilation (SV). Methods: Prospective, randomized, clinical study. Methods: A group of 30 client-owned horses, 8-156 months old (range), with body masses of 280-550 kg. Methods: Anesthesia protocol consisted of xylazine, ketamine and diazepam, and maintenance with isoflurane and a CRI of dexmedetomidine. All g...
Kim T, Lee S, Seo JP.Foot diseases are common causes of lameness in horses. Computed tomography (CT) is a valuable tool for diagnosing musculoskeletal lesions in horses and providing a detailed evaluation of foot diseases. Objective: The objective of this study was to establish reference ranges related to the feet of normal Jeju horses by measuring the angles and length of the hoof, and the Hounsfield Unit (HU) value of soft tissues in the foot. Methods: Sixteen normal Jeju horses (mean age: 4.25 years; mean body weight: 282.06 kg) without lameness were examined using CT. After CT scanning, the angles and lengths ...
Zhang C, Cai E, Ma Y, Zhong G, Gao Y, Wu Y, Liu B, Li J.This study investigated the cyathostomin species composition, anthelmintic efficacy, and potential resistance-associated mutations in Chinese grazing horses. Fecal samples were collected from 90 adult horses. Fecal egg counts (FECs) were determined using a modified McMaster method. Third stage larvae (L3) cultured from the eggs were identified to species level by PCR amplification and sequencing of the internal transcribed spacer-2 (ITS-2). The main species included and spp. However, differences in the relative abundance of less common species, including and , suggests regional variation. A...
Zanacchi A, Fruscione F, Grasselli S, Razzuoli E, Pastorino L, Di Lisa D.Developing advanced preclinical in vitro cancer models is essential for understanding tumor biology, improving drug discovery, and enhancing the clinical translation of new therapies. Papillomaviruses (PVs) cause diverse lesions in humans and animals; notably, bovine papillomavirus (BPV) is the main cause of equine sarcoid, the most common skin tumor in horses. Its pathogenesis involves viral infection, fibroblast transformation, and extracellular matrix (ECM) remodeling. These processes highlight the limitations of conventional two-dimensional (2D) culture systems, which fail to replicate the...
Sullivan J, Blea J, McKemie DS, Kass PH, Knych HK.The pharmacokinetics and pharmacodynamics of betamethasone following intra-articular administration to horses have been described; however, studies characterizing intramuscular administration are lacking. Twenty-four horses received an intramuscular dose of 12 mg betamethasone sodium phosphate/betamethasone acetate. Blood and urine were collected at post administration for up to 408 h. Concentrations of betamethasone were determined using LC-MS/MS and pharmacokinetic parameters determined using a Population PK three-compartment model. The duration of pharmacodynamic effects was assessed by...
Penzhorn L, Crafford JE, Guthrie AJ.African horse sickness (AHS) is the only equine disease for which the World Organisation for Animal Health (WOAH) gives official disease-free status, given that it poses a major threat to the equine industry. The disease is caused by AHS virus (AHSV; family , taxon species ), which is endemic in sub-Saharan Africa. Reverse-transcription quantitative real-time PCR (RT-qPCR) is a rapid, sensitive detection method used in the diagnosis of AHS and the certification of animals as negative for AHSV for the purpose of movement. Genetic variability of AHSV may influence the accuracy of RT-qPCR detecti...
Haussler KK.Congenital cervical vertebral anomalies in horses are structural changes in the neck vertebrae that develop during the fetal stage. These anomalies can vary in their severity and effects. Some horses may not show any clinical signs and can live normally, while others may develop serious problems such as spinal cord compression. This compression can lead to issues like ataxia or even paralysis, affecting the horse's mobility and quality of life. Recognizing and diagnosing these anomalies early are very important, as it helps guide decisions about the best treatment options and overall managemen...
Nelson BB, Easley JT.Ventral cervical stabilization remains the primary surgical approach, in general, for horses with spinal cord compression. Advancements in volumetric imaging offer a more comprehensive understanding of central nervous system dysfunction elucidating that other modes of compression exist. Minimally invasive instrumentation and computer-assisted surgery are expanding therapeutic possibilities for cervical vertebral compressive myelopathy, radiculopathy, vertebral fractures, and intracranial or intraspinal masses. Emerging techniques-such as articular process joint fixation, targeted decompression...
Nelson BB, Easley JT.Equine neurosurgery is a challenge for many surgeons, particularly when central nervous system (CNS) disease is not addressed through ventral cervical stabilization, the most performed neurosurgical procedure. Advances in diagnostic imaging, minimally invasive instrumentation, and computer-assisted surgery are expanding therapeutic possibilities beyond cervical vertebral compressive myelopathy, including radiculopathy, vertebral fractures, and intracranial or intraspinal masses. Emerging techniques-such as percutaneous foraminotomy, facet fixation, targeted decompression, novel implant systems...
Satué K, Fazio E, Velasco-Martínez MG, Barbiera G, La Fauci D.Growth hormone (GH) influences follicular development mainly by stimulating insulin-like growth factor 1 (IGF-1), which acts systemically and locally within the ovary. However, the metabolic profile of follicular fluid (FF) in mares, particularly markers such as fructosamine (FRUCT), an indicator of glucose metabolism, remains poorly characterized. This study aimed to evaluate GH, IGF-1, and FRUCT concentrations in plasma and FF and their variation across follicle sizes. Sixty ovaries were collected during the breeding season from 30 clinically normal mares raised for meat production. Blood sa...
Nocera I, Cingottini D, Di Franco C, Sala G, Bindi F, Spadari A, Rinnovati R, Vitale V, Jose-Cunilleras E, Sgorbini M.Several studies investigated risk and prognostic parameters for horses with colic; however, the consensus is still debated. The present work aimed to investigate colic outcomes and to identify risk factors in horses referred for colic. In this multicenter retrospective study, 236 clinical records of equids referred for colic at three different equine centers were reviewed. The following data were collected: history, signalment, physical examination at the time of admission, hematological and biochemical analysis, diagnosis, SIRS status and 0-6 point-scale SIRS score, colic type, treatment atte...
Jung Y, Yoon M.Oxytocin (OXT) plays a crucial role in regulating the serotonin (5-HT) system and behavior. Although previous studies have reported significant relationships among OXT, 5-HT, and behavioral responses, the effects of OXT on 5-HT concentrations and behavioral traits in horses remain poorly understood. This study aimed to investigate the effects of intravenous OXT administration on plasma 5-HT concentrations and trainability in horses. A crossover design was employed using eight horses, each receiving either a 10-IU intravenous dose of OXT or normal saline. Blood samples were collected at baselin...
Dao TTH, Szűts T, Duong NN, Troung DTQ, Solymosi N, Takács N, Hornok S, Farkas R.Equine piroplasmosis, caused by , and , significantly impacts on the veterinary and economic aspects of the global horse industry. However, many countries, including Vietnam, have not yet conducted epidemiological surveys to determine the prevalence of these haemoparasites. This study aimed to detect and/or infections in horses and to identify their genotypes. Blood samples were collected from 154 apparently healthy horses in eight districts of Hanoi, Thai Nguyen, and Son La provinces located in the northern part of the country. Twenty-four horses (15.58%, 95%CI: 10.70–22.14%) were found ...
Whitelock A, Goodwin W, Dryburgh L, Mshelbwala PP, Rae L, Marwedel L, Lok T, Kemp K, Stewart AJ.To describe Australian practices and attitudes regarding equine analgesia. Methods: Cross-sectional anonymous, voluntary survey of Australian veterinarians treating equine patients. Methods: Australian veterinarians in equine or mixed practices completed a six-section, 60-question survey between November 2019 to August 2020. Information was gathered on demographics, analgesia prescription, pain assessment and attitudes surrounding specific analgesics. Respondents assigned a pain score ranging from 0 to 10 for various conditions; these were averaged to give each respondent an "average pain scor...
Equine chronic degenerative endometritis (CDE) is a progressive process characterized by endometrial fibrosis that could be responsible for alterations of uterine environment and foetal-maternal communication. Objective: The aim of this study was to try to restore this communication by intrauterine administrations of amniotic cell-derived extracellular vesicles (AMC-EVs) in a case series. Methods: Twelve mares were selected on the basis of their reproductive history of early embryonic loss or abortion and clinical suspicion of CDE subsequently verified with histopathological examination of end...
Teague P, Dark M, Verdugo D, Freeman D, McFarlane D.The equine pancreas remains understudied, particularly in the context of endocrine disease. This study aimed to characterize regional islet distribution and composition in the normal equine pancreas and investigate how hyperinsulinemia (HI) and pituitary pars intermedia dysfunction (PPID) influence pancreatic islet morphology and hormone expression. In the first experiment, pancreas samples from eight healthy horses were collected and analyzed across three anatomical locations: left lobe, body, and right lobe. The left lobe exhibited a greater relative islet area and perimeter compared to the ...
Rissi DR, Mendes RE.Squamous cell carcinoma (SCC) is the most common ocular and periocular neoplasm of horses, typically arising from the limbus, third eyelid mucosa or mucocutaneous junctions of the upper and lower eyelids. Tumours are locally invasive, prone to recurrence and may rarely metastasize. Histological evaluation is required for definitive diagnosis and atypical SCC subtypes may be diagnostically challenging. Here we describe a clear cell SCC in the third eyelid of a 16-year-old female Quarter Horse. The red and invasive mass was surgically excised for histological evaluation. The lesion consisted of ...
Fernandes MD, Ribeiro GSN, Joaquim JGF, Ferraz SM, Fonteque JH.In equine husbandry, oral cavity procedures are commonly performed and may be associated with complications, including extraoral diseases, potentially resulting from bacterial contamination and inadequate antisepsis. Bacterial resistance to antimicrobials is a major issue for healthcare professionals, including veterinarians that may misuse these pharmaceuticals. Therefore, developing novel methods for antisepsis is desirable. This study aims to test the effectiveness of a 100 µg/ml ozonized injectable water solution versus 0.12% chlorhexidine mouthwash. Fifty adult equines had swab samples...
DeClue A, Workman K, May-Davis S.To date, radiographically identifying the bony landmarks relevant to diagnosing the complete C6 aplasia of the caudal lamina ventralis (C6 aCLV4) has not been described. Furthermore, a gross study has identified C6 aCLV4 as the main correlation between transposition of the CLV from C6 to C7, where coinciding neck pain was commonly reported. This study aimed to identify C6 aCLV4 in radiographs, where the outcome might benefit equine practitioners in isolating neck pain. Initially, the relevant bony landmarks were radiographically determined from a normal C6 by applying a lateral 30° dorsal-ven...
Hoogelander B, Frippiat T, Bergman HJ, Vanderperren K, van Veggel ECS.Thoracolumbar congenital abnormalities are considered rare in mature, performing horses. This case report describes a 14-year-old Welsh pony presented with marked epaxial muscle atrophy, mid-thoracic spinal pain, and stiffness, most pronounced during canter. The thoracic spine exhibited scoliosis, centered at T9-T10, and kyphosis. Radiography and postmortem computed tomography revealed complex congenital malformations of the thoracic vertebral column, including abnormal morphology of the T10-T12 vertebral bodies, partial vertebral fusion, a malformed spinous process, a malformed rib with assoc...
Dos Santos TS, Dillmann JB, Giovelli M, Elias GO, Lima RK, Cescon S, Stainki DR, Dos Santos RC, Corrêa C, Monteiro SG.This study reports the successful use of maggot therapy in four horses with traumatic wounds caused by wire fences, treated in veterinary clinics and under field conditions in southern Brazil. All lesions showed tissue necrosis, purulent discharge, and foul odor, indicating infection and delayed healing. Sterile Lucilia cuprina larvae (L1 stage) were applied directly to the wounds for 48 hours. Rapid improvement was observed, with marked reduction of necrotic tissue, exudate, and odor, and stimulation of granulation tissue in three cases. Complete wound closure occurred between 10 and 60 days ...
Böckmann S, Trzebiatowski L, Georgiev P, Büttner K, Wehrend A.Immunoglobulins ingested via colostrum must remain intact to be absorbed by the neonate. Equine colostrum contains antitrypsin activity, which likely protects these proteins from proteolysis in the gastrointestinal tract. Objective: To quantify antitrypsin activity in equine colostrum and milk, describe its temporal changes during the first five days after parturition, compare actitvity between left and right mammary glands, evaluate differences between nulliparous and pluriparous mares, and examine associations with immunoglobulin G (IgG) concentrations and mare age. Methods: This retrospecti...
Motta D, Aymée L, Roussouliéres I, Di Azevedo MIN, Jacob JCF, Lilenbaum W.Leptospirosis is a zoonotic disease caused by spirochetes of the genus Leptospira. Equine genital leptospirosis (EGL) has been described as a chronic and silent syndrome, presenting reproductive alterations such as abortion, stillbirth, placentitis, embryonic loss, repeat breeding syndrome, and subfertility. This study aimed to investigate the genital Leptospira infection in naturally infected mares with poor reproductive performance, as well as to genetically characterize the agents. A total of 41 mares with a history of poor reproductive performance were selected. Sera were collected for ser...
Bryan A, Shapir N, Sadowsky MJ.Nonselected and natural populations of Escherichia coli from 12 animal sources and humans were examined for the presence and types of 14 tetracycline resistance determinants. Of 1,263 unique E. coli isolates from humans, pigs, chickens, turkeys, sheep, cows, goats, cats, dogs, horses, geese, ducks, and deer, 31% were highly resistant to tetracycline. More than 78, 47, and 41% of the E. coli isolates from pigs, chickens, and turkeys were resistant or highly resistant to tetracycline, respectively. Tetracycline MICs for 61, 29, and 29% of E. coli isolates from pig, chickens, and turkeys, respect...
Moran CJ, Ramesh A, Brama PA, O'Byrne JM, O'Brien FJ, Levingstone TJ.Much research is currently ongoing into new therapies for cartilage defect repair with new biomaterials frequently appearing which purport to have significant regenerative capacity. These biomaterials may be classified as medical devices, and as such must undergo rigorous testing before they are implanted in humans. A large part of this testing involves in vitro trials and biomechanical testing. However, in order to bridge the gap between the lab and the clinic, in vivo preclinical trials are required, and usually demanded by regulatory approval bodies. This review examines the in vivo models ...
Gabriels RL, Pan Z, Dechant B, Agnew JA, Brim N, Mesibov G.This study expands previous equine-assisted intervention research by evaluating the effectiveness of therapeutic horseback riding (THR) on self-regulation, socialization, communication, adaptive, and motor behaviors in children with autism spectrum disorder (ASD). Methods: Participants with ASD (aged 6-16 years; N = 127) were stratified by nonverbal IQ standard scores (≤85 or >85) and randomized to 1 of 2 groups for 10 weeks: THR intervention or a barn activity (BA) control group without horses that used similar methods. The fidelity of the THR intervention was monitored. Participants ...
Barlough JE, Madigan JE, DeRock E, Bigornia L.A nested polymerase chain reaction for detecting Ehrlichia equi in horses and ticks (Ixodes pacificus) was developed. A major second-round PCR product of 928 bp could be readily visualized in ethidium bromide-stained agarose minigels. An internal probe was used to verify the identity of the amplified product by non-radioactive (digoxigenin-based) Southern blotting; additional confirmation was provided by DNA sequence analysis. A dilution study testing the sensitivity of the PCR indicated that DNA derived from 3 infected neutrophils was sufficient to generate a PCR signal. The specificity of t...
Nugent J, Birch-Machin I, Smith KC, Mumford JA, Swann Z, Newton JR, Bowden RJ, Allen GP, Davis-Poynter N.Equid herpesvirus 1 (EHV-1) can cause a wide spectrum of diseases ranging from inapparent respiratory infection to the induction of abortion and, in extreme cases, neurological disease resulting in paralysis and ultimately death. It has been suggested that distinct strains of EHV-1 that differ in pathogenic capacity circulate in the field. In order to investigate this hypothesis, it was necessary to identify genetic markers that allow subgroups of related strains to be identified. We have determined all of the genetic differences between a neuropathogenic strain (Ab4) and a nonneuropathogenic ...
van Kasteren PB, Bailey-Elkin BA, James TW, Ninaber DK, Beugeling C, Khajehpour M, Snijder EJ, Mark BL, Kikkert M.Protein ubiquitination regulates important innate immune responses. The discovery of viruses encoding deubiquitinating enzymes (DUBs) suggests they remove ubiquitin to evade ubiquitin-dependent antiviral responses; however, this has never been conclusively demonstrated in virus-infected cells. Arteriviruses are economically important positive-stranded RNA viruses that encode an ovarian tumor (OTU) domain DUB known as papain-like protease 2 (PLP2). This enzyme is essential for arterivirus replication by cleaving a site within the viral replicase polyproteins and also removes ubiquitin from cell...
Weese JS.Methicillin-resistant Staphylococcus aureus (MRSA) is a critically important human pathogen that is also an emerging concern in veterinary medicine and animal agriculture. It is present in a wide range of animal species, including dogs, cats, rabbits, horses, cattle, pigs, poultry, and exotic species, both as a cause of infection and in healthy carriers. Identification of MRSA in various species and in food has led to concerns about the roles of animals, both pets and livestock, in the epidemiology of MRSA infection and colonization in humans. There is evidence of the role of food animals in h...
Hauck SM, Dietter J, Kramer RL, Hofmaier F, Zipplies JK, Amann B, Feuchtinger A, Deeg CA, Ueffing M.Autoimmune uveitis is a blinding disease presenting with autoantibodies against eye-specific proteins as well as autoagressive T cells invading and attacking the immune-privileged target tissue retina. The molecular events enabling T cells to invade and attack the tissue have remained elusive. Changes in membrane protein expression patterns between diseased and healthy stages are especially interesting because initiating events of disease will most likely occur at membranes. Since disease progression is accompanied with a break-down of the blood-retinal barrier, serum-derived proteins mask the...
Bunning ML, Bowen RA, Cropp CB, Sullivan KG, Davis BS, Komar N, Godsey MS, Baker D, Hettler DL, Holmes DA, Biggerstaff BJ, Mitchell CJ.A total of 12 horses of different breeds and ages were infected with West Nile virus (WNV) via the bites of infected Aedes albopictus mosquitoes. Half the horses were infected with a viral isolate from the brain of a horse (BC787), and half were infected with an isolate from crow brain (NY99-6625); both were NY99 isolates. Postinfection, uninfected female Ae. albopictus fed on eight of the infected horses. In the first trial, Nt antibody titers reached >1:320, 1:20, 1:160, and 1:80 for horses 1 to 4, respectively. In the second trial, the seven horses with subclinical infections developed Nt a...
Komar N, Clark GG.West Nile virus (Flavivirus: Flaviviridae; WNV) has spread rapidly throughout the Caribbean Basin since its initial detection there in 2001. This report summarizes our current knowledge of WNV transmission in tropical America. Methods: We reviewed the published literature and consulted with key public health officials to obtain unpublished data. Results: West Nile virus infections first appeared in human residents of the Cayman Islands and the Florida Keys in 2001, and in apparently healthy Jamaican birds sampled early in 2002. Serologic evidence of WNV infection in 2002 was detected in horses...
Patel JR, Heldens J.This review concentrates on the epidemiology, latency and pathogenesis of, and the approaches taken to control infection of horses by equine herpesvirus types 1 (EHV-1) and 4 (EHV-4). Although both viruses may cause febrile rhinopneumonitis, EHV-1 is the main cause of abortions, paresis and neonatal foal deaths. The lesion central to these three conditions is necrotising vasculitis and thrombosis resulting from lytic infection of endothelial cells lining blood capillaries. The initiation of infection in these lesions is likely to be by reactivated EHV-1 from latently infected leukocytes. Howev...
Timoney JF.Streptococci pathogenic for the horse include S. equi (S. equi subsp. equi), S. zooepidemicus (S. equi subsp. zooepidemicus), S. dysgalactiae subsp. equisimilis and S. pneumoniae capsule Type III. S. equi is a clonal descendent or biovar of an ancestral S. zooepidemicus strain with which it shares greater than 98% DNA homology and therefore expresses many of the same proteins and virulence factors. Rapid progress has been made in identification of virulence factors and proteins uniquely expressed by S. equi. Most of these are expressed either on the bacterial surface or are secreted. Notable e...
Schnabel LV, Lynch ME, van der Meulen MC, Yeager AE, Kornatowski MA, Nixon AJ.Tendinitis remains a catastrophic injury among athletes. Mesenchymal stem cells (MSCs) have recently been investigated for use in the treatment of tendinitis. Previous work has demonstrated the value of insulin-like growth factor-I (IGF-I) to stimulate cellular proliferation and tendon fiber deposition in the core lesion of tendinitis. This study examined the effects of MSCs, as well as IGF-I gene-enhanced MSCs (AdIGF-MSCs) on tendon healing in vivo. Collagenase-induced bilateral tendinitis lesions were created in equine flexor digitorum superficialis tendons (SDFT). Tendons were treated with ...
Cai W, Ryan U, Xiao L, Feng Y.Giardia duodenalis is a common intestinal parasite in various hosts, with the disease giardiasis being a zoonosis. The use of molecular typing tools has improved our understanding of the distribution and zoonotic potential of G. duodenalis genotypes in different animals. The present review summarizes recent data on the distribution of G. duodenalis genotypes in humans and animals in different areas. The dominance of G. duodenalis assemblages A and B in humans and common occurrence of host-adapted assemblages in most domesticated animals suggests that zoonotic giardiasis is probably less common...
Guy JS, Breslin JJ, Breuhaus B, Vivrette S, Smith LG.A coronavirus was isolated from feces of a diarrheic foal and serially propagated in human rectal adenocarcinoma (HRT-18) cells. Antigenic and genomic characterizations of the virus (isolate NC99) were based on serological comparison with other avian and mammalian coronaviruses and sequence analysis of the nucleocapsid (N) protein gene. Indirect fluorescent-antibody assay procedures and virus neutralization assays demonstrated a close antigenic relationship with bovine coronavirus (BCV) and porcine hemagglutinating encephalomyelitis virus (mammalian group 2 coronaviruses). Using previously des...
Wilke MM, Nydam DV, Nixon AJ.Mesenchymal stem cells (MSCs) provide an important source of pluripotent cells for musculoskeletal tissue repair. This study examined the impact of MSC implantation on cartilage healing characteristics in a large animal model. Twelve full-thickness 15-mm cartilage lesions in the femoropatellar articulations of six young mature horses were repaired by injection of a self-polymerizing autogenous fibrin vehicle containing mesenchymal stem cells, or autogenous fibrin alone in control joints. Arthroscopic second look and defect biopsy was obtained at 30 days, and all animals were euthanized 8 month...
Marklund L, Moller MJ, Sandberg K, Andersson L.The melanocyte-stimulating hormone receptor gene (MC1R) is the major candidate gene for the chestnut coat color in horses since it is assumed to be controlled by an allele at the extension locus. MC1R sequences were PCR amplified from chestnut (e/e) and non-chestnut (E/-) horses. A single-strand conformation polymorphism was found that showed a complete association to the chestnut coat color among 144 horses representing 12 breeds. Sequence analysis revealed a single missense mutation (83Ser-->Phe) in the MC1R allele associated with the chestnut color. The substitution occurs in the second ...
Steelman SM, Chowdhary BP, Dowd S, Suchodolski J, Janečka JE.The nutrition and health of horses is closely tied to their gastrointestinal microflora. Gut bacteria break down plant structural carbohydrates and produce volatile fatty acids, which are a major source of energy for horses. Bacterial communities are also essential for maintaining gut homeostasis and have been hypothesized to contribute to various diseases including laminitis. We performed pyrosequencing of 16S rRNA bacterial genes isolated from fecal material to characterize hindgut bacterial communities in healthy horses and those with chronic laminitis. Results: Fecal samples were collected...
Leclere M, Lavoie-Lamoureux A, Lavoie JP.Animal models have been developed to investigate specific components of asthmatic airway inflammation, hyper-responsiveness or remodelling. However, all of these aspects are rarely observed in the same animal. Heaves is a naturally occurring disease of horses that combines these features. It is characterized by stable dust-induced inflammation, bronchospasm and remodelling. The evaluation of horses during well-controlled natural antigen exposure and avoidance in experimental settings allows the study of disease mechanisms in the asymptomatic and symptomatic stages, an approach rarely feasible ...
Rogers GN, Pritchett TJ, Lane JL, Paulson JC.Human and animal (avian and equine) influenza A virus isolates of the H3 serotype exhibit marked differences in their ability to bind specific sialyloligosaccharide sequences that serve as cell surface receptor determinants (G. Rogers and J. Paulson, 1983, Virology 127, 361-373). Whereas human isolates of this subtype strongly agglutinate enzymatically modified human erythrocytes containing the terminal SA alpha 2,6Gal sequence, avian and equine isolates preferentially agglutinate erythrocytes bearing the SA alpha 2, 3Gal sequence. As shown in this report, a glycoprotein found in horse serum, ...
Dick LK, Bernhard AE, Brodeur TJ, Santo Domingo JW, Simpson JM, Walters SP, Field KG.The purpose of this study was to examine host distribution patterns among fecal bacteria in the order Bacteroidales, with the goal of using endemic sequences as markers for fecal source identification in aquatic environments. We analyzed Bacteroidales 16S rRNA gene sequences from the feces of eight hosts: human, bovine, pig, horse, dog, cat, gull, and elk. Recovered sequences did not match database sequences, indicating high levels of uncultivated diversity. The analysis revealed both endemic and cosmopolitan distributions among the eight hosts. Ruminant, pig, and horse sequences tended to for...
Garmashova N, Atasheva S, Kang W, Weaver SC, Frolova E, Frolov I.The encephalitogenic New World alphaviruses, including Venezuelan (VEEV), eastern (EEEV), and western equine encephalitis viruses, constitute a continuing public health threat in the United States. They circulate in Central, South, and North America and have the ability to cause fatal disease in humans and in horses and other domestic animals. We recently demonstrated that these viruses have developed the ability to interfere with cellular transcription and use it as a means of downregulating a cellular antiviral response. The results of the present study suggest that the N-terminal, approxima...
Campo MS.Tumorigenesis due to papillomavirus (PV) infection was first demonstrated in rabbits and cattle early last century. Despite the evidence obtained in animals, the role of viruses in human cancer was dismissed as irrelevant. It took a paradigm shift in the late 1970s for some viruses to be recognised as 'tumour viruses' in humans, and in 1995, more than 60 years after Rous's first demonstration of CRPV oncogenicity, WHO officially declared that 'HPV-16 and HPV-18 are carcinogenic to humans'. Experimental studies with animal PVs have been a determining factor in this decision. Animal PVs have bee...
McCarthy HE, Bara JJ, Brakspear K, Singhrao SK, Archer CW.A chondrocyte progenitor population isolated from the surface zone of articular cartilage presents a promising cell source for cell-based cartilage repair. In this study, equine articular cartilage progenitor cells (ACPCs) and equine bone marrow-derived stromal cells (BMSCs) were compared as potential cell sources for repair. Clonally derived BMSCs and ACPCs demonstrated expression of the cell fate selector gene, Notch-1, and the putative stem cell markers STRO-1, CD90 and CD166. Chondrogenic induction revealed positive labelling for collagen type II and aggrecan. Collagen type X was not detec...
Baldacchino F, Desquesnes M, Mihok S, Foil LD, Duvallet G, Jittapalapong S.Tabanids are nuisance pests for people and livestock because of their painful and irritating bite, persistent biting behavior, and blood ingestion. About 4400 tabanid species have been described; they are seasonally present in all kinds of landscapes, latitudes, and altitudes. High populations have a significant economic impact on outdoor activities, tourism, and livestock production. Tabanids are also vectors of animal disease agents, including viruses, bacteria and parasites. However, tabanids have received little attention in comparison with other hematophagous Diptera. Here, we highlight t...
Wong K, van der Weyden L, Schott CR, Foote A, Constantino-Casas F, Smith S, Dobson JM, Murchison EP, Wu H, Yeh I, Fullen DR, Joseph N, Bastian BC....Mucosal melanoma is a rare and poorly characterized subtype of human melanoma. Here we perform a cross-species analysis by sequencing tumor-germline pairs from 46 primary human muscosal, 65 primary canine oral and 28 primary equine melanoma cases from mucosal sites. Analysis of these data reveals recurrently mutated driver genes shared between species such as NRAS, FAT4, PTPRJ, TP53 and PTEN, and pathogenic germline alleles of BRCA1, BRCA2 and TP53. We identify a UV mutation signature in a small number of samples, including human cases from the lip and nasal mucosa. A cross-species comparative...
Love S, Murphy D, Mellor D.Cyathostomes are now the principle parasitic pathogen of the horse: a remarkable transformation during the last 25 years from virtual obscurity to focus of attention in equine parasitology. This rise to prominence coincides with the marked decrease in prevalence of large strongyle infections as a result of widespread use of modern anthelmintic compounds. On the basis that strongyle-associated diseases continue to commonly occur in the absence of these large strongyle species, clinical attention has turned to the pathogenicity of cyathostomes. Although many horses harbour burdens of tens of tho...
