Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Rudolf Vegas A, Podico G, Canisso IF, Bollwein H, Almiñana C, Bauersachs S.During the period of maternal recognition of pregnancy (MRP) in the mare, the embryo needs to signal its presence to the endometrium to prevent regression of the corpus luteum and prepare for establishment of pregnancy. This is achieved by mechanical stimuli and release of various signaling molecules by the equine embryo while migrating through the uterus. We hypothesized that embryo's signals induce changes in the endometrial gene expression in a highly cell type-specific manner. A spatiotemporal transcriptomics approach was applied combining laser capture microdissection and low-input-RNA se...
Rodríguez N, Whitfield-Cargile CM, Chamoun-Emanuelli AM, Hildreth E, Jordan W, Coleman MC.The nasopharyngeal bacterial and fungal microbiota of normal horses and those with nasopharyngeal cicatrix syndrome (NCS) are unknown. Objective: To describe the microbiota from nasopharyngeal washes of healthy horses and of horses acutely affected with NCS. Methods: Twenty-six horses acutely affected with NCS horses and 14 unaffected horses. Methods: Prospective, observational cohort study. Horses were recruited by investigators through personal communications in central Texas. Bacterial (16s RNA) and fungal (internal transcribed spacer) microbiota from nasopharyngeal washes were evaluated. P...
Bou T, Han H, Mongke T, Zhao R, La X, Ding W, Jia Z, Liu H, Tiemuqier A, An T, Dugarjaviin M, Bai D.The heterogeneity and plasticity of muscle fibers are essential for the athletic performance of horses, mainly at the adaption of exercises and the effect on muscle diseases. Skeletal muscle fibers can be generally distinguished by their characteristics of contraction as slow and fast type myofibers. The diversity of contractile properties and metabolism enable skeletal muscles to respond to the variable functional requirements. We investigated the muscle fiber composition and metabolic enzyme activities of splenius muscle and gluteus medius muscle from Mongolian horses. The deep RNA-seq analy...
Birras J, White SJ, Jonsdottir S, Novotny EN, Ziegler A, Wilson AD, Frey R, Torsteinsdottir S, Alcocer M, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis in horses incited by salivary allergens from Culicoides spp. IBH does not occur in Iceland, as the causative agents are absent, however a high prevalence is seen in horses exported to Culicoides-rich environments. To study the natural course of sensitization to Culicoides allergens and identify the primary sensitizing allergen(s) in horses exported from Iceland utilizing a comprehensive panel of Culicoides recombinant (r-) allergens. IgE microarray profiling to 27 Culicoides r-allergens was conducted on 110 serological s...
Mild-moderate (MEA), severe (SEA) equine asthma and exercise-induced pulmonary hemorrhage (EIPH) are common respiratory disorders in horses. The present retrospective study aims to evaluate the role of ultrasonography and endoscopy in the diagnosis of these conditions. Three hundred and three horses were included and divided into SEA, MEA and MEA + EIPH groups, on the basis of history, clinical examination and bronchoalveolar lavage fluid (BALf) cytology; scores were assigned to lung ultrasonography, pharyngeal lymphoid hyperplasia (PLH), tracheal mucus (TM) and tracheal bifurcation edema (TB)...
Patton ME, Leise BS, Baker RE, Andrews FM.To determine the influence of bit chewing on gastrointestinal transit in clinically normal horses. Methods: Prospective crossover designed study. Methods: Six healthy adult horses. Methods: Horses were assigned randomly to treatment (apple flavored bit) and control (no-bit) groups and studied for 2 × 1-week trial periods with a 2-week washout period between trials. Horses were fasted for 24 h and slowly refed over 3 days. The bit was placed for 20 min every 6 h. Duodenal contractions and borborygmi auscultations were evaluated every 12 h, approximately 5 min following bit placemen...
Thompson RE, Meyers MA, Pukazhenthi BS, Hollinshead FK.Reproductive diseases in mares are a significant cause of subfertility and profound economic loss in the equine industry. Utilizing a 3D in vitro cell culture system that recapitulates the in vivo physiology will reduce time, cost, and welfare concerns associated with in vivo reproductive research in mares. If this 3D model is combined with effective cryopreservation, reproductive research on mares can occur year-round, which is not currently possible in this seasonal species. Endometrial organoids, 3D in vitro cell clusters that exhibit in vivo uterine physiology, have been established in mic...
Flick M, Vinther AML, Jacobsen S, Berg LC, Gimeno M, Verwilghen D, Howden W, Averay K, van Galen G.Serum neutrophil gelatinase-associated lipocalin (sNGAL) is a marker of renal injury, and its concentrations are affected by inflammation. Therefore, it could serve as a useful biomarker of disease or fitness in high-level competition. However, it has not yet been determined if sNGAL concentrations are affected by exercise. The aim of this study was to determine whether concentrations of equine sNGAL were affected by 1000 m galloping as the form of exercise used in the study. Pre- and post-gallop sNGAL, serum amyloid A, and creatinine concentrations were evaluated in 14 healthy Thoroughbred r...
Weber LA, Delarocque J, Feige K, Kietzmann M, Kalbitz J, Meißner J, Paschke R, Cavalleri JV.The naturally occurring betulinic acid (BA) and its derivative NVX-207 induce apoptosis in equine melanoma cells in vitro. After topical application, high concentrations of the substances can be reached in healthy equine skin. With the aim to investigate the effect and safety of topically applied BA and NVX-207 in horses with melanocytic tumors, the longitudinal, prospective, randomized, double-blind, placebo-controlled study protocol included eighteen Lipizzaner mares with early-stage cutaneous melanoma assigned to three groups. Melanocytic lesions were topically treated either with a placebo...
Ginther OJ.After the cessation of equine embryo mobility (fixation) on mean Day 16, the embryonic vesicle is rotated or oriented so that the pole with the embryo proper is opposite to the mesometrial attachment. Orientation involves massage of the vesicle by contractions of the turgid uterine horn and greater thickening of the vesicle at the pole with the embryo proper. Thickening of the dorsal endometrium (encroachment) especially on each side of the mesometrial attachment accounts for a guitar-pick shape of the vesicle when viewed in cross section of the uterine horn. On Days 21-40, the allantoic sac e...
Turner CM, Reiswig J, Manfredi JM.Periodontal disease has been identified in horses and donkeys through the millennia at a prevalence of up to 75% and is a leading cause of tooth loss in horses. We hypothesize that there is a correlation between tooth elongations and periodontal disease. Dental records of all client owned horses examined by a single AVDC/equine board certified practitioner in 2016-2018 were analyzed. Inclusion criteria consisted of the examination finding of tooth elongation of one of the following teeth pairs 106/107, 206/207, 310/311, or 410-411. The included cases were then examined for the finding of perio...
Kamm JL, Riley CB, Parlane NA, Gee EK, McIlwraith CW.Mesenchymal stromal cells (MSCs) are believed to be hypoimmunogeneic with potential use for allogeneic administration. Bone marrow was harvested from Connemara (n = 1), Standardbred (n = 6), and Thoroughbred (n = 3) horses. MSCs were grouped by their level of expression of major histocompatibility factor II (MHC II). MSCs were then sub-grouped by those MSCs derived from universal blood donor horses. MSCs were isolated and cultured using media containing fetal bovine serum until adequate numbers were acquired. The MSCs were cultured in xenogen-free media for 48 h prior to use and d...
Willette JA, Kopper JJ, Kogan CJ, Seguin MA, Schott HC.We investigated the effects of season and geographic location on detection of nucleic acids of potential enteric pathogens (PEPs) or their toxins (PEP-Ts) in feces of horses ≥6-mo-old in the United States. Results of 3,343 equine diarrhea PCR panels submitted to Idexx Laboratories for horses >6-mo-old were reviewed. Submission months were grouped into 4 seasons, and states were grouped into 4 geographic regions. Logistic regression was performed to assess effects of season and region on detection rates of PEPs and PEP-Ts. Agresti-Coull CIs were determined. Detection rate of was higher in...
Biau S, Burgaud I.Kinesiology taping (KT) has been used on human subjects for many years. More recently, KT has been used in sport horses. The physiological mechanisms involved remain unclear and its benefits are controversial. Objective: To investigate the effects of application of kinesiology taping to abdominal muscles on locomotor parameters before and after lungeing exercise in horses. Methods: Cross-over study. Methods: Eleven horses were tested twice, once with an application of KT without tension on abdominal muscles (condition 1) and once with a facilitation application of KT on abdominal muscles (cond...
Agerholm JS, Klas EM, Damborg P, Borel N, Pedersen HG, Christoffersen M. Loss of pregnancy in mares can have many different causes, including both infectious and non-infectious conditions. Extrapolation of findings from other studies is often uncertain as the significance of each cause varies across regions. Causes of pregnancy loss in mares have never been thoroughly studied in Denmark, so a prospective cross-sectional cohort study targeting the entire Danish population of pregnant mares was performed over a period of 13 months to obtain knowledge of the significance of individual causes. Fifty aborted or prematurely delivered stillborn fetuses were submitted for...
Peano A, Arnoldi S, Čmoková A, Hubka V.This article reports the first verified cases of infection by Trichophyton bullosum in Africa since the description of the fungus, isolated in 1933 from the coat of horses in Tunisia and Mali. We found the fungus in cutaneous samples obtained from donkeys suffering from severe dermatitis with areas of alopecia and scaling in the surroundings of Cairo (Egypt). Fungal elements (arthroconidia and hyphae) were seen at the microscopy of material collected by skin scraping and digested in NaOH. Fungal colonies grown on various culture media were identified through PCR and sequencing of the ITS rDNA ...
Holl HM, Armstrong C, Galantino-Homer H, Brooks SA.Laminitis results in impaired tissue integrity and Inflammation of the epidermal and dermal lamellae connecting the hoof capsule to the underlying distal phalanx and causes loss-of-use, poor quality of life and euthanasia in horses. Historically, studies to better understand the etiology of laminitis by documenting changes in gene expression were hampered by the paucity of gene annotation specific to hoof tissues. Next-generation sequencing enables improvements to annotation by incorporating equine- and hoof-specific transcripts. Here we characterize the hoof lamellar tissue transcriptome of n...
Kelemen Z, Grimm H, Long M, Auer U, Jenner F.Recumbency is a prerequisite for horses achieving rapid eye movement (REM) sleep and completing a full sleep cycle. An inability to lie down due to environmental insecurities or pain results in REM sleep deficiency, which can cause substantial impairment of welfare and health. Therefore, the present study used wearable automated sensor technology on 83 horses housed in an animal sanctuary to measure and compare the recumbency, locomotion, and standing time budgets of geriatric horses with and without chronic lameness to younger adult sound and lame horses. Recumbency times ranged from 0 to 319...
Karikoski NP, Box JR, Mykkänen AK, Kotiranta VV, Raekallio MR.The oral sugar test (OST) is commonly used to diagnose insulin dysregulation (ID) and equine metabolic syndrome; however, possible seasonal changes in OST results have not been evaluated. Objective: To determine the possible variation in insulin response to OST throughout the year and risk factors associated with maximum insulin concentration (InsMax) and ID. Methods: Prospective, longitudinal cohort study. Methods: The OST was performed on 29 Finnhorses every other month six times. Serum total adiponectin concentration and phenotypic variables related to obesity were also measured. Changes in...
May A, Gesell-May S, Müller T, Ertel W.Due to recent developments in artificial intelligence, deep learning, and smart-device-technology, diagnostic software may be developed which can be executed offline as an app on smartphones using their high-resolution cameras and increasing processing power to directly analyse photos taken on the device. Objective: A software tool was developed to aid in the diagnosis of equine ophthalmic diseases, especially uveitis. Methods: Prospective comparison of software and clinical diagnoses. Methods: A deep learning approach for image classification was used to train software by analysing photograph...
Flanagan S, Rowe Á, Duggan V, Markle E, O'Brien M, Barry G.Warmblood Fragile Foal syndrome (WFFS) is an autosomal recessive condition that affects the maturation of collagen in affected foals. Foals affected with the disease typically die or are euthanised shortly after birth. WFFS is caused by a single nucleotide change at position 2032 of the equine PLOD1 gene, causing an impairment of the wild-type enzyme. A commercial test for the causative genetic mutation is currently available from companies operating under licence from Cornell University but it has limitations. This test requires amplification of a region of the PLOD1 gene encompassing the sit...
Stolz I, Tillmann V, Anneken V, Froboese I.Scientific investigation and documentation of equine-assisted therapy has increased over the past several years. Yet there are no standardized and validated tools for evidence-based measurement of processes and outcomes to assess equine-assisted interventions. Objective: The objective of this cross-sectional survey study was to develop a standardized assessment tool for the effective measurement of equine-assisted therapy based on the common language of the International Classification of Functioning, Disability and Health (ICF) framework of the World Health Organization (WHO). Methods: Cross-...
Buckley P, Buckley DJ, Freire R, Hughes KJ.Marked increases in serum muscle enzyme activity can occur in endurance horses but the diagnostic certainty in predicting cases of myopathy is unclear. Improved understanding of horse management effects on serum muscle enzyme activity as markers of muscle health would assist interpretation of serum muscle enzyme activity and guide management to reduce myopathy risk. Objective: To investigate associations between serum muscle enzyme activity and management factors in endurance horses. Methods: Cross-sectional study. Methods: One hundred endurance horses competing in four endurance events (offer...
Yoon J, Park T, Kim A, Song H, Park BJ, Ahn HS, Go HJ, Kim DH, Lee JB, Park SY, Song CS, Lee SW, Choi IS.Equine parvovirus-cerebrospinal fluid (EqPV-CSF) and eqcopivirus (EqCoPV) are new parvovirus species (EqPVs) identified from various tissues (CSF, blood, and respiratory swabs) in horses with neurologic and respiratory diseases. In this study, we described the prevalence rate of EqPV-CSF and EqCoPV in 133 and 77 serum and fecal samples, respectively, using polymerase chain reaction. Further, we analyzed the potential risk factors for infection. We calculated the nucleotide and amino acid similarity and constructed phylogenetic trees. There was a moderate-to-high prevalence rate (EqPV-CSF: 3.8%...
Paßlack N, van Bömmel-Wegmann S, Vahjen W, Zentek J.Zinc supplements are often used in equine nutrition to support skin and hoof quality or the immune function. However, no data on the effects of dietary zinc on the intestinal microbiota of horses and ponies are available so far. In the present study, varying dietary zinc concentrations (maintenance (4 mg/kg BW/day), 120 mg/kg dry matter (DM)/day and 240 mg/kg DM/day) were achieved by the supplementation of either zinc chloride hydroxide or zinc methionine (six treatment periods of 4 weeks each). Eight healthy adult ponies and two healthy adult horses were included, and faecal samples were coll...
De Lange L, Van Steenkiste G, Vernemmen I, Vera L, Cromheeke KMC, Walser U, Meert H, Decloedt A, van Loon G.Rate-adaptive single chamber pacemakers with accelerometer, closed loop stimulation (CLS), and remote monitoring functionality (Eluna 8 SR-T, Biotronik, SE & Co, Germany) were implanted in 3 miniature donkeys with third-degree atrioventricular block and syncope. After recovery, different pacemaker programming modes were tested at rest, during stress without physical exercise and during physical exercise. Pacing rates were compared to actual atrial rates and showed that CLS functionality allowed physiological heart rate adaptation. A transmitter installed in the stable provided wireless connect...
Ciota AT.Eastern equine encephalitis virus (EEEV; Togaviridae, Alphavirus) is an arthropod-borne virus (arbovirus) primarily maintained in an enzootic cycle between Culiseta melanura (Coquillett) and passerine birds. EEEV, which has the highest reported case- fatality rate among arbovirus in the Americas, is responsible for sporadic outbreaks in the Eastern and Midwest United States. Infection is associated with severe neurologic disease and mortality in horses, humans, and other vertebrate hosts. Here, we review what is known about EEEV taxonomy, functional genomics, and evolution, and identify gaps i...
Bozorgmanesh R, Thornton J, Snyder J, Fletcher C, Mack R, Coyne M, Murphy R, Hegarty E, Slovis N.Symmetric dimethylarginine (SDMA) is a renal biomarker correlated with glomerular filtration rate (GFR). Objective: Describe changes in SDMA in clinically healthy foals and their mares during the first month postfoaling. Methods: Convenience sampling of healthy periparturient Thoroughbred mares and their full-term foals from a population of client-owned horses. Methods: Serum and EDTA whole blood samples were collected from mares in their last month of pregnancy and then from mares and foals at approximately <12 hours, 48 hours, 7 days, and 30 days postbirth. Samples were processed ...
Armstrong PM, Andreadis TG.In the current review, we examine the regional history, ecology, and epidemiology of eastern equine encephalitis virus (EEEV) to investigate the major drivers of disease outbreaks in the northeastern United States. EEEV was first recognized as a public health threat during an outbreak in eastern Massachusetts in 1938, but historical evidence for equine epizootics date back to the 1800s. Since then, sporadic disease outbreaks have reoccurred in the Northeast with increasing frequency and northward expansion of human cases during the last 20 yr. Culiseta melanura (Coquillett) (Diptera: Culicidae...
Stobierski MG, Signs K, Dinh E, Cooley TM, Melotti J, Schalow M, Patterson JS, Bolin SR, Walker ED.Eastern equine encephalomyelitis (EEE) is a mosquito-borne viral disease that is an emerging public health concern in the state of Michigan. Although Michigan has one of the highest incidence rates of EEE in the United States, much of the information known about cases in humans, equines, and other animals residing in Michigan is unpublished. This article summarizes such information and explores spatial trends in the historic distribution of EEE in Michigan. Outbreaks in Michigan have occurred over an 80-yr interval, involving only horses in 1942-1943 and 1973-1976, and then episodically from 1...
Katavolos P, Ackerley CA, Viel L, Clark ME, Wen X, Bienzle D.Horses are prone to recurrent airway obstruction (RAO), an inflammatory lung disease induced by repeated exposure to environmental mold, dust, and bacterial components. Active disease manifests with mucus hyperproduction, neutrophilic inflammation, bronchoconstriction, and coughing. Chronically affected animals have lung remodeling characterized by smooth muscle hyperplasia, collagen deposition, lymphoid hyperplasia, and impaired aerobic performance. Clara cell secretory protein (CCSP) counters inflammation in the lung, hence we hypothesized that CCSP depletion is a key feature of RAO in horse...
Sloboda M, Jirků M, Lukešová D, Qablan M, Batsukh Z, Fiala I, Hořín P, Modrý D, Lukeš J.Equine piroplasmosis caused by Babesia caballi and Theileria equi is widespread in Asia. The presence of these haemozoans in Mongolia was previously confirmed in domestic as well as in reintroduced Przewalski horses in which they cause significant pathology. The data on occurrence of piroplasms from Bactrian camels in Asia is lacking. A total of 192 horses, 70 Bactrian camels, and additional 16 shepherd dogs from the Hentiy province were included in our study. No clinical signs typical for piroplasmid infection were observed during the field survey. Microscopic examination revealed the presenc...
Venter GJ, Koekemoer JJ, Paweska JT.Confirmed outbreaks of African horse sickness (AHS) occurred in the surveillance zone of the Western Cape in 1999 and 2004, both of which led to a two-year suspension on the export of horses. Light trap surveys in the outbreak areas showed that known vector competent Culicoides species, notably C. imicola, were abundant and present in numbers equal to those in the traditional AHS endemic areas. Isolations of AHS virus serotypes 1 and 7, equine encephalosis virus, and bluetongue virus from field-collected C. imicola in the surveillance zone demonstrated that this species was highly competent an...
Díaz-Sánchez AA, Pires MS, Estrada CY, Cañizares EV, Del Castillo Domínguez SL, Cabezas-Cruz A, Rivero EL, da Fonseca AH, Massard CL....Equine piroplasmosis is a disease of Equidae, including horses, donkeys, mules, and zebras, caused by either Theileria equi or Babesia caballi. This disease represents a serious problem for the horse industry and its control is critical for the international trade of horses. The objective of the present study was to detect B. caballi and T. equi infections in horses reared in western Cuba. Blood samples from 100 horses were tested for the presence of piroplasms by using Giemsa-stained blood smears and nested PCR (nPCR) assays targeting merozoite antigen genes of B. caballi (bc48) and T. equi (...
Belknap JK, Giguère S, Pettigrew A, Cochran AM, Van Eps AW, Pollitt CC.Recent research has indicated that inflammation plays a role in the early stages of laminitis and that, similar to organ failure in human sepsis, early inflammatory mechanisms may lead to downstream events resulting in lamellar failure. Characterisation of the type of immune response (i.e. innate vs. adaptive) is essential in order to develop therapeutic strategies to counteract these deleterious events. Objective: To quantitate gene expression of pro-inflammatory cytokines known to be important in the innate and adaptive immune response during the early stages of laminitis, using both the bla...
Barrachina L, Romero A, Zaragoza P, Rodellar C, Vázquez FJ.Since the clinical use of mesenchymal stem cells (MSCs) for treating musculoskeletal injuries is gaining popularity, practitioners should be aware of the factors that may affect MSCs from tissue harvesting for MSC isolation to cell delivery into the injury site. This review provides equine practitioners with up-to-date, practical knowledge for the treatment of equine patients using MSCs. A brief overview of laboratory procedures affecting MSCs is provided, but the main focus is on shipping conditions, routes of administration, injection methods, and which commonly used products can be combined...
Leise B.Equine laminitis is a devastating disease in which failure of the adhesion between the digital dermal and epidermal laminae at the basement membrane results in crippling lameness and structural damage to the foot of the horse. Laminitis occurring secondary to sepsis is known to result from a significant inflammatory response that includes leukocyte emigration into the lamellar tissue. These leukocytes, in particular the neutrophil, have been extensively evaluated in experimental models of sepsis-related laminitis in the horse. This review will discuss the relevant findings elucidated from thes...
Sponseller BT, Valberg SJ, Schultz NE, Bedford H, Wong DM, Kersh K, Shelton GD.Seasonal pasture myopathy (SPM) is a highly fatal form of nonexertional rhabdomyolysis that occurs in pastured horses in the United States during autumn or spring. In Europe, a similar condition, atypical myopathy (AM), is common. Recently, a defect of lipid metabolism, multiple acyl-CoA dehydrogenase deficiency (MADD), has been identified in horses with AM. Objective: To determine if SPM in the United States is caused by MADD. Methods: Six horses diagnosed with SPM based on history, clinical signs, and serum creatine kinase activity, or postmortem findings. Methods: Retrospective descriptive ...
Diallo AA, Souley MM, Issa Ibrahim A, Alassane A, Issa R, Gagara H, Yaou B, Issiakou A, Diop M, Ba Diouf RO, Lo FT, Lo MM, Bakhoum T, Sylla M....Since November 2018, several countries in West and Central Africa have reported mortalities in donkeys and horses. Specifically, more than 66,000 horses and donkeys have succumbed to disease in Burkina Faso, Chad, Cameroon, The Gambia, Ghana, Mali, Niger, Nigeria, and Senegal. Strangles caused by Streptococcus equi subsp equi, African Horse Sickness (AHS) virus, and Equine influenza virus (EIV) were all suspected as potential causative agents. This study reports the identification of EIV in field samples collected in Niger and Senegal. Phylogenetic analysis of the hemagglutinin and neuraminida...
Alves AG, Stewart AA, Dudhia J, Kasashima Y, Goodship AE, Smith RK.Tendon and ligament injuries have proved difficult to treat effectively. Cell-based therapies offer the potential to harness the complex protein synthetic machinery of the cell to induce a regenerative response rather than fibrous scarring. This article reviews the current state of play with respect to the clinically used cell preparations for the treatment of tendon and ligaments overstrain injuries.
Woodward EM, Troedsson MH.Transient post breeding endometritis is a normal physiological reaction in the mare, as it is believed that an inflammatory response is necessary for the effective removal of contaminating bacteria and excess spermatozoa introduced into the uterus. While most mares can clear endometritis within a reasonable amount of time, persistent endometritis caused by either bacteria or spermatozoa can threaten the success of a pregnancy. A subpopulation of mares is susceptible to persistent endometritis, and these mares are a concern in equine reproductive medicine. Research has identified several factor...
Chénier S, Côté G, Vanderstock J, Macieira S, Laperle A, Hélie P.Eastern equine encephalomyelitis (EEE) was diagnosed in 19 horses and a flock of emus in the province of Quebec in fall 2008. The EEE virus caused unusual gross lesions in the central nervous system of one horse. This disease is not usually present in Quebec and the relation between the outbreak and favorable environmental conditions that summer are discussed. Une éclosion d’encéphalomyélite équine de l’Est (ÉÉE) s’est produite chez 19 chevaux et dans un troupeau d’émeus au Québec à l’automne de 2008. Un cheval présentait une lésion macroscopique anormale dans le système...
Zhang C, Ni P, Ahmad HI, Gemingguli M, Baizilaitibei A, Gulibaheti D, Fang Y, Wang H, Asif AR, Xiao C, Chen J, Ma Y, Liu X, Du X, Zhao S.Animal domestication gives rise to gradual changes at the genomic level through selection in populations. Selective sweeps have been traced in the genomes of many animal species, including humans, cattle, and dogs. However, little is known regarding positional candidate genes and genomic regions that exhibit signatures of selection in domestic horses. In addition, an understanding of the genetic processes underlying horse domestication, especially the origin of Chinese native populations, is still lacking. In our study, we generated whole genome sequences from 4 Chinese native horses and combi...
Barba M, Fairbanks EL, Daly JM.Members of several different virus families cause equine viral encephalitis, the majority of which are arthropod-borne viruses (arboviruses) with zoonotic potential. The clinical signs caused are rarely pathognomonic; therefore, a clinical diagnosis is usually presumptive according to the geographical region. However, recent decades have seen expansion of the geographical range and emergence in new regions of numerous viral diseases. In this context, this review presents an overview of the prevalence and distribution of the main viral causes of equine encephalitis and discusses their impact an...
Nicander L, Malmqvist M.Principal cells in the initial segment of the epididymis in horses, cattle, pigs, sheep, dogs, cats, and rabbits have an abundant, partly rough, endoplasmic reticulum and a large Golgi complex. Small vacuoles with opaque content seem to be formed by the Golgi complex and move to the cell apex, where they empty their contents into the lumen by a merocrine mechanism.
Corbin LJ, Kranis A, Blott SC, Swinburne JE, Vaudin M, Bishop SC, Woolliams JA.Despite the dramatic reduction in the cost of high-density genotyping that has occurred over the last decade, it remains one of the limiting factors for obtaining the large datasets required for genomic studies of disease in the horse. In this study, we investigated the potential for low-density genotyping and subsequent imputation to address this problem. Results: Using the haplotype phasing and imputation program, BEAGLE, it is possible to impute genotypes from low- to high-density (50K) in the Thoroughbred horse with reasonable to high accuracy. Analysis of the sources of variation in imput...
Alloway E, Linder K, May S, Rose T, DeLay J, Bender S, Tucker A, Luff J.Squamous cell carcinoma (SCC) is the most common neoplasm of the equine stomach. However, the mechanisms underlying malignant transformation are unknown. As papillomavirus-2 (EcPV-2) is a likely cause of some genital SCCs, we hypothesized that EcPV-2 is associated with a subset of equine gastric SCCs. To this aim, we performed polymerase chain reaction (PCR) and in situ hybridization (ISH) for EcPV-2 E6/ E7 oncogenes on 11 gastric SCCs and on gastric samples from 15 control horses with no SCC. PCR for EcPV-2 was positive in 7/11 (64%) gastric SCCs; non-SCC gastric samples were all negative. I...
Fenger CK, Granstrom DE, Gajadhar AA, Williams NM, McCrillis SA, Stamper S, Langemeier JL, Dubey JP.Sarcocystis sp. sporocysts isolated from eight feral opossums (Didelphis virginiana) were pooled and fed to 18 commercially reared budgerigars (Melopsittacus undulatus), 14 wild-caught sparrows (Passer domesticus), one wild-caught slate-colored Junco (Junco hyemalis) and five weanling horses (Equus caballus). All budgerigars died within 5 weeks post inoculation (wpi). Histologic examination revealed meronts within the pulmonary epithelia and typical Sarcocystis falcatula sarcocysts developing in the leg muscles. Sparrows were euthanized 13 and 17 wpi and their carcasses were fed to four labora...
Leegwater PA, Vos-Loohuis M, Ducro BJ, Boegheim IJ, van Steenbeek FG, Nijman IJ, Monroe GR, Bastiaansen JW, Dibbits BW, van de Goor LH, Hellinga I....Inbreeding and population bottlenecks in the ancestry of Friesian horses has led to health issues such as dwarfism. The limbs of dwarfs are short and the ribs are protruding inwards at the costochondral junction, while the head and back appear normal. A striking feature of the condition is the flexor tendon laxity that leads to hyperextension of the fetlock joints. The growth plates of dwarfs display disorganized and thickened chondrocyte columns. The aim of this study was to identify the gene defect that causes the recessively inherited trait in Friesian horses to understand the disease proce...
Theoret CL.The equine practitioner who is presented with a wounded horse should fully understand the physiologic mechanisms involved in repair so as to design an appropriate treatment plan. In the following articles of this issue,experienced authors share their thoughts on the management of specific injuries, and the reader should benefit from acquisition of knowledge about the different phases of healing as well as the cytokines that regulate them,because these data dictate the approach to follow, particularly in com-plicated wounds, such as those afflicted by chronic inflammation and/or an excessive pr...
Timoney JF, Kumar P.Little is known about entry and subsequent multiplication of Streptococcus equi following exposure of a susceptible horse. This information would have value in design of intranasal vaccines and understanding of shedding and protective immune responses. Objective: To determine entry points and sites of subsequent replication and dispersion of S. equi at different times after intranasal infection or commingling exposure. Methods: Previously unexposed horses and ponies were subjected to euthanasia 1, 3, 20 or 48 h following intranasal inoculation with biotin labelled or unlabelled S. equi CF32. S...
Daly K, Shirazi-Beechey SP.Nine oligonucleotide probes complementary to conserved regions of small subunit rRNA from phylogenetically defined clusters of intestinal anaerobic bacteria were designed and evaluated for use in quantitative analysis of intestinal microflora. Optimum wash temperatures (T(w)) were determined according to the temperature of dissociation (T(d)) of each probe and target group specificity was demonstrated by comparing hybridisation to target and non-target rRNA immobilised on nylon membranes. Three probes are targeted to phylogenetic clusters of Clostridiaceae, clusters III, IV and IX, with three ...
Wagner B.Since the initial characterization of IgE by Ishizaka et al. (1966), IgE was described in several mammalian species. In horses, a single gene encoding the IgE heavy chain constant region (IGHE gene) exists per haploid genome and several allelic variants of the equine IGHE gene were found. IgE occurs in its soluble form in equine serum and physiological concentrations of total IgE are around 1000-fold higher in normal horse than in normal human serum. Maternal IgE is enriched in the colostrum and transferred to the neonatal foal after birth. Foals do not produce detectable concentrations of end...
Nuñez CM, Adelman JS, Rubenstein DI.Although the physiological effects of immunocontraceptive treatment with porcine zona pellucida (PZP) have been well studied, little is known about PZP's effects on the scheduling of reproductive cycling. Recent behavioral research has suggested that recipients of PZP extend the receptive breeding period into what is normally the non-breeding season. Results: To determine if this is the case, we compiled foaling data from wild horses (Equus caballus) living on Shackleford Banks, North Carolina for 4 years pre- and 8 years post-contraception management with PZP (pre-contraception, n = 65 births...
Nielsen MK, von Samson-Himmelstjerna G, Kuzmina TA, van Doorn DCK, Meana A, Rehbein S, Elliott T, Reinemeyer CR.This guideline have been developed to assist in the design, execution, and interpretation of studies to assess the efficacy of anthelmintic drugs against internal parasites of equines, including nematodes, cestodes, and larval instars of Gasterophilus spp. The design and execution of critical and controlled studies are outlined, and their advantages and disadvantages are discussed. Unique considerations for specific target parasites are included. Information is also provided on selection of animals, procedures for randomization, housing, feeding, dosage titration, dosage confirmation and field...
Raspa F, Dinardo FR, Vervuert I, Bergero D, Bottero MT, Pattono D, Dalmasso A, Vinassa M, Valvassori E, Bruno E, De Palo P, Valle E.Horses reared for meat production are fed high amounts of cereal grains in comparison with horses raised for other purposes. Such feeding practice may lead to risk of poor welfare consequences. The aim of this study was to investigate the effects of two feeding practices on selected metabolic parameters and production aspects. Nineteen Bardigiano horses, 14.3 ± 0.7 months of age, were randomly assigned to two groups-one fed with high amounts of cereal grains (HCG; n = 9; 43% hay plus 57% cereal grain-based pelleted feed) vs. one fed with high amounts of fibre (HFG; n = 10; 70% hay plus...
Clausen PH, Chuluun S, Sodnomdarjaa R, Greiner M, Noeckler K, Staak C, Zessin KH, Schein E.From May to July 2000, a cross-sectional study was conducted to estimate the prevalence of Trypanosoma equiperdum in the horse population of the central province (Tuv aimag) of Mongolia. On average, four herds were selected from each of the 29 aimag subdivisions (119 herds). From each herd, 10 horses were sampled in proportion to sex and age categories in the respective herds (1190 horses). Sera from 1122 horses were analysed for T. equiperdum antibodies using two serological assays, the complement fixation test (CFT) and the enzyme-linked immunosorbent assay (ELISA). The crude estimate of the...
Kelmer G, Keegan KG, Kramer J, Wilson DA, Pai FP, Singh P.To characterize compensatory movements of the head and pelvis that resemble lameness in horses. Methods: 17 adult horses. Methods: Kinematic evaluations were performed while horses trotted on a treadmill before and after shoe-induced lameness. Lameness was quantified and the affected limb determined by algorithms that measured asymmetry in vertical movement of the head and pelvis. Induced primary lameness and compensatory movements resembling lameness were assessed by the Friedman test. Association between induced lameness and compensatory movements was examined by regression analysis. Results...
Thomas E, Thomas V, Wilhelm C.Cefquinome is known for its use as an antibacterial drug in cattle and pigs. The objective of this study was to evaluate the antibacterial activity of cefquinome against equine pathogenic bacteria. The minimum inhibitory concentration (MIC) of cefquinome was determined for a total of 205 strains, which had recently been isolated in Europe from diseased horses (respiratory infection, foal septicaemia). The bactericidal activity was tested against 19 strains using the time killing method. The post-antibiotic effect (PAE) and post-antibiotic sub-MIC effect (PA SME) were determined against 12 stra...
