Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Hobbs KJ, Le Sueur ANV, Hallowell K, Martin E, Sheats MK, Ueda Y.An 8-year-old American Quarter Horse gelding was treated with extracorporeal hemoperfusion (HP) therapy for treatment of Clostridioides difficile (C. difficile) colitis-induced systemic inflammatory response syndrome (SIRS). The gelding developed C. difficile associated peracute colitis and severe SIRS as evidenced by a positive fecal C. difficile PCR and tachypnea, tachycardia, fever, neutropenia, altered mucous membrane color, and hyperlactatemia. Concurrent acute kidney injury in the horse limited the use of routine anti-inflammatory and anti-lipopolysaccharide treatments, including flunixi...
Ventura MCDS, Neves JMM, Pinheiro RDS, Santos MVC, de Lemos ERS, Horta MAP.Rabies, a zoonotic viral disease, poses a significant threat due to its adaptability to diverse environments. Herbivore rabies, predominantly affecting cattle, horses, and goats in Brazil, remains a concern, results in substantial losses in the livestock industry, and poses risks to public health. Rabies virus transmission, primarily through hematophagous bats in Latin America, underscores the need for effective strategies, and vaccination plays a crucial role in controlling herbivorous rabies, with systematic vaccination beingly the primary method. Efforts to control rabies in herbivores incl...
Zhong D, Zheng J, Ma Z, Wang Y, Wei J.The prevalence and impact of Getah virus (GETV) are significant concerns in China. GETV can infect a wide range of animals, including horses, pigs, sheep, cattle, birds, and humans, resulting in substantial losses in the livestock and agricultural industries. GETV infection can cause the development of ulcers and inflammation in the mouth and gums of horses, which result in pain and discomfort and lead to symptoms such as reduced appetite, drooling, and difficulty chewing. As a result, there is a pressing need for efficient and rapid disease diagnosis methods. However, the currently available ...
Woo PCY, Mheiri FA, Cavalleri J, Joseph S, Tang JYM, Joseph M, Tsang CC, Lau SKP, Wernery U.Epizootic lymphangitis (EL) is a highly prevalent and contagious infectious disease affecting horses in many parts of Ethiopia caused by Histoplasma capsulatum sensu lato ('var. farciminosum'). In this study, 12 suspected isolates of H. capsulatum sensu lato or yeasts unidentified by conventional biochemical tests isolated from Ethiopian horses with EL were characterised by ITS sequencing. Six of the 12 isolates were identified to be members of H. capsulatum sensu lato and the other six were Pichia kudriavzevii (synonym: Candida krusei) (n = 3), Trichosporon asahii (n = 1), Geotrichum silv...
Scholtz M, Guthrie AJ, Newton R, Schulman ML.Three bacteria extensively acknowledged as venereal pathogens with the potential to induce endometritis include Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), specific strains of Pseudomonas aeruginosa, and certain capsule types of Klebsiella pneumoniae. The United Kingdom's Horserace Betting Levy Board recommends pre-breeding screening for these bacteria in their International Codes of Practice and >20 000 samples are tested per annum in the United Kingdom alone. While the pathogenesis and regulatory importance of CEM are well established, an evaluation...
Martínez-Sáez L, Pala S, Marín-García PJ, Llobat L.Toxoplasmosis is one of the most common parasitic zoonoses and represents a significant health risk for humans, especially for immunodeficient patients. The main transmission route is by oral uptake of oocysts and consumption of undercooked meat of infected animals. Different species have been evaluated as possible reservoirs of the parasite, but few studies have been carried out to examine the role of horses in transmission of the disease. Given the proximity of these animals to humans and the widespread consumption of their meat in many countries, including the Mediterranean basin, it is imp...
Arroyo LG, Gomez DE, Moore A, Papapetrou M, Lillie BN.Our objective was to determine whether equine herpesviruses 1 (EHV-1) viral nucleic acids could be detected immediately after foaling from nasal and vaginal swabs, whole blood, and placental tissue of healthy mares. Unassigned: Nasal and vaginal swabs, EDTA blood, and placental tissue (296 samples) were collected from 74 clinically healthy postpartum broodmares within 24 h after giving birth to live, clinically healthy foals. All samples were tested (PCR) for nucleic acids of neuropathogenic and non-neuropathogenic strains of EHV-1, and all were negative. Unassigned: As EHV-1 was not detected ...
Hobbs KJ, Cooper BL, Dembek K, Sheats MK.Cell-free DNA (cfDNA) is fragmented extracellular DNA that is released from cells into various body fluids. Previously published data from adult horses supports cfDNA as a potential disease biomarker, but also shows that direct measurement in plasma is inaccurate due to matrix effect. It is currently unknown whether a similar matrix effect exists in foal plasma. Given this, the objectives of the current study were to investigate foal plasma for potential matrix effect during fluorescence measurement of cfDNA using a Qubit fluorometer, and to determine whether neat and/or extracted plasma cfDNA...
Ringo RS, Choonnasard A, Okabayashi T, Saito A. can establish persistent infections in animals such as equids, pigs, nonhuman primates, rodents, and possums. Some can even cause overt and severe diseases such as Equine Arteritis in horses and Porcine Reproductive and Respiratory Syndrome in pigs, leading to huge economic losses. have evolved viral proteins to antagonize the host cell's innate immune responses by inhibiting type I interferon (IFN) signaling, assisting viral evasion and persistent infection. So far, the role of the glycoprotein 5 (GP5) protein in IFN signaling inhibition remains unclear. Here, we investigated the inhibito...
White NA, Flynn K.The purpose of the study was to assess the challenges faced by state animal health officials (SAHOs) when managing equine disease outbreaks. Methods: A survey was conducted to assess SAHOs' collaboration with horse owners and practicing veterinarians to provide biosecurity and infection disease control. It was sent to 180 email addresses listed in the Equine Disease Communication Center website database. The responses in each category for each question were tabulated and reported as a percentage. Results: There were 72 survey responses from 45 states. The number of states responding suggested ...
Steiner MN, Boone LH, Hayden L, Schumacher J, Arnold CE.To describe the indications for and surgical technique of mastectomy of mares and to describe the outcome of 10 mares that underwent mastectomy in a retrospective case series. Methods: 10 mares having disease of one or both mammary glands. Methods: Medical records (1995 to 2022) from 2 university teaching hospitals were searched to identify mares that had undergone unilateral or bilateral mastectomy. Data regarding history, signalment, diagnostic tests, preoperative treatment, surgical procedure, and postoperative management were reviewed. Follow-up information was obtained by interviewing the...
Kabir A, Lamichhane B, Habib T, Adams A, El-Sheikh Ali H, Slovis NM, Troedsson MHT, Helmy YA.The equine industry holds substantial economic importance not only in the USA but worldwide. The occurrence of various infectious bacterial diseases in horses can lead to severe health issues, economic losses, and restrictions on horse movement and trade. Effective management and control of these diseases are therefore crucial for the growth and sustainability of the equine industry. While antibiotics constitute the primary treatment strategy for any bacterial infections in horses, developing resistance to clinically important antibiotics poses significant challenges to equine health and welfa...
Portaels J, Van Crombrugge E, Van Den Broeck W, Lagrou K, Laval K, Nauwynck H.Numerous Aspergillus fumigatus (Af) airborne spores are inhaled daily by humans and animals due to their ubiquitous presence. The interaction between the spores and the respiratory epithelium, as well as its impact on the epithelial barrier function, remains largely unknown. The epithelial barrier protects the respiratory epithelium against viral infections. However, it can be compromised by environmental contaminants such as pollen, thereby increasing susceptibility to respiratory viral infections, including alphaherpesvirus equine herpesvirus type 1 (EHV-1). To determine whether Af spores di...
Stasiak K, Dunowska M, Rola J.Equine rhinitis A (ERAV) and B (ERBV) viruses are respiratory pathogens with worldwide distribution. The current study aimed to determine the frequency of infection of ERAV and ERBV among horses and foals at Polish national studs, and to determine genetic variability within the viruses obtained. Virus-specific quantitative RT-PCR assays targeting a 5' untranslated region were used to screen nasal swabs collected from 621 horses at 16 national horse studs from throughout Poland, including 553 healthy horses and 68 horses with respiratory disease. A partial DNA polymerase gene was amplified and ...
Maeda M, Abe M, Aoshima K, Kobayashi A, Fukushi H, Kimura T.Equine herpesvirus-1 (EHV-1) causes respiratory diseases, abortion, and encephalomyelitis in horses. The EHV-1 immediate-early (IE) protein, essential for viral replication, is transactivated by the binding of a multiprotein complex including the open reading frame 12 (ORF12) and some host factors to the IE promoter region. Promoter-associated non-coding RNAs (pancRNAs), which are transcribed from bidirectional promoters, regulate the transcription of neighboring genes in mammals and pathogens. In this study, we identified a novel pancRNA transcribed from across the areas of the 5'-untranslate...
Shams F, Jokar M, Abdous A, Mohammadi P, Abbassioun A, Seuberlich T, Rahmanian V.Neospora spp. and Toxoplasma gondii are two closely related protozoan parasites that are widely distributed throughout the world. Horses can act as intermediate hosts for both parasites and can acquire disease. Blood samples were taken from 487 clinically healthy horses from 17 different mechanized stables in Tehran, the capital of Iran, during September and November of 2022. IFAT and ELISA were employed to detect antibodies directed against Neospora spp. and T. gondii. The anti-N. caninum antibodies were detected in 52 of the horses (10.67%) based on IFAT and in 86 of the 487 horses (17.65%) ...
Lacante SA, Jiang C, Mustamir AA, Mizuno T, Bi X, Syafruddin D, Tokoro M., a human intestinal protozoan parasite of the diplomonad group, has been overlooked because of its commensal features; therefore, molecular studies on this parasite are limited. To address this gap, we designed a molecular screening protocol using polymerase chain reaction (PCR) and DNA sequencing targeting the 18S small subunit ribosomal RNA gene and applied this screening method to the molecular epidemiological analysis of spp. in humans and various livestock. We validated our methodology using stool samples collected from 215 humans and 270 animal hosts (buffaloes, pigs, dogs, goats, hors...
Olguin-Perglione C, Politzki R, Alvarez I, Ruiz V.The novel Equine Parvovirus-Hepatitis (EqPV-H) was first identified in the serum and liver of a horse that died of equine serum hepatitis, also known as Theiler's disease. Several reports in recent years strongly suggest that EqPV-H is the etiologic agent of Theiler's disease. Brazil is the only South American country where infection with this virus has been reported. This study investigated the presence of EqPV-H DNA in horse serum pools (n=51), commercial horse serum batches (n=5) and individual serum samples from donor horses (n=175) from Argentina. All serum samples were analyzed by quanti...
Rar V, Marchenko V, Suntsova O, Epikhina T, Tikunov A, Meltsov I, Fedorets V, Igolkina Y, Kozlova I, Tikunova N.Equine piroplasmosis (EP) is a global worldwide infection, which can lead to the death of animals. Despite the causative agents of EP being well studied, there are no data on the distribution and genetic characteristics of EP agents in any region of Russia. In this study, blood samples from 750 horses from Novosibirsk province, Irkutsk province, and Altai region of Russian Siberia were examined for the presence of EP agents. Theileria equi and Babesia caballi were detected in all examined regions, with mean prevalence rates of 60.4% and 7.2%, respectively. The identified pathogens were genetic...
Uchida-Fujii E, Kato Y, Ueno T, Numasawa Y, Yusa S, Haga T.Equus caballus papillomavirus 2 (EcPV2) is known to cause genital neoplasms in horses. However, reports on EcPV2 in Japan and Asia are limited. Herein, we present the histopathological and virological findings of the first reported case of an EcPV2-associated penile mass in Japan. The patient was a 22-year-old stallion with a history of breeding in Japan and abroad. Histopathological examination contained RNA in situ hybridization targeting the E6/E7 region and an immunohistochemical approach, and whole-genome sequencing was conducted within the viral examination. Proliferating epidermal cells...
Tau RL, Marandino AE, Panzera Y, Alamos F, Vissani MA, Romera SA, Pérez R, Maidana SS.The Equid alphaherpesvirus type 1 (EHV-1) infection can have devastating economic consequences in the horse industry due to large-scale outbreaks of abortions, perinatal foal mortality, and myeloencephalopathy. The present study analyzed the genome of two isolates obtained from aborted fetuses in Argentina, E/745/99 and E/1297/07. The E745/99 genome shares 98.2% sequence identity with Ab4, a reference EHV-1 strain. The E/1297/07 genome shares 99.8% identity with NY03, a recombinant strain containing part of ORF64 and part of the intergenic region from Equid alphaherpesvirus-4 (EHV-4). The E/12...
Molini U, Franzo G, de Villiers L, van Zyl L, de Villiers M, Khaiseb S, Busch F, Knauf S, Dietze K, Eiden M.The present study investigated the seropositivity rate of Hepatitis E virus (HEV) in domestic and working animals in Namibia, which included dogs, cats, horses, and donkeys. HEV poses a growing threat as a significant cause of human hepatitis globally and has several genotypes of varying zoonotic potential. As epidemiological data on the seroprevalence of HEV in Namibia is scarce, a serosurvey was conducted on archived serum samples of 374 dogs, 238 cats, 98 horses, and 60 donkeys collected between 2018 and 2022 from different regions, to assess the potential of these animals as sources of HEV...
Hallowell KL, Hepworth-Warren KL, Dembek K.Available descriptive studies on equine pneumonia are outdated or focus on specific horse or bacterial populations. Objective: To describe the clinical presentation and bacterial isolates of adult horses with bacterial pneumonia and identify factors associated with death. Methods: One hundred sixteen horses >2 years old with bacterial pneumonia. Methods: Retrospective case series. Data regarding history, physical examination, clinicopathologic features, treatment, bacterial culture and sensitivity, and outcome were collected and analyzed retrospectively. Results: Historical risk factors w...
Mita H, Kuroda T, Minamijima Y, Tamura N, Ohta M.Surgical-site infections (SSIs) at implant sites in horses are sometimes difficult to control with systemic antimicrobials. Because one of the likely reasons is insufficient antimicrobial concentrations, there is a need to increase these concentrations in and around the infected tissue. Marbofloxacin (MAR)-encapsulated microparticles (MAR-MPs) made of biodegradable poly (lactic-co-glycolic) acid are capable of sustained release in vitro. We examined the concentration of MAR in the subcutaneous tissue fluid at sites where MAR-MPs had been administered. On day 0, six 3- × 4-cm subcutaneous pock...
Costa MVD, Rodrigues GD, Lima HIL, Krolow TK, Krüger RF.Tabanidae (Diptera), popularly known as horse flies, is an important vector group. This is the first study to ascertain the abundance and diversity of horse flies in horses at the cerrado biome of the state of Tocantins, Brazil. Collecting took place in typical Cerrado, and sampling occurred in the dry and rainy seasons. The horseflies were collected from horses using an entomological net. A total of 249 individuals were collected and spread over 25 species. The prevalent species were Stypommisa aripuana (25.8%) and Catachlorops rufescens (6.4%), in the dry period, and Fidena lissorhina (22.5%...
Schramm A, Ackermann M, Eichwald C, Aguilar C, Fraefel C, Lechmann J.Equid alphaherpesviruses 1 (EHV-1) and 4 (EHV-4) are closely related and both endemic in horses worldwide. Both viruses replicate in the upper respiratory tract, but EHV-1 may additionally lead to abortion and equine herpesvirus myeloencephalopathy (EHM). We focused on antibody responses in horses against the receptor-binding glycoprotein D of EHV-1 (gD1), which shares a 77% amino acid identity with its counterpart in EHV-4 (gD4). Both antigens give rise to cross-reacting antibodies, including neutralizing antibodies. However, immunity against EHV-4 is not considered protective against EHM. Wh...
Roberts DM, Gilger BC.Equine fungal keratitis represents a substantial portion of keratitis cases in horses, with fungal involvement identified in approximately half of all infectious keratitis cases. Despite its prevalence, more comprehensive retrospective analyses are needed to better understand this condition. Outcomes vary, with approximately two-thirds of cases achieving complete healing with retained vision, although enucleation is often necessary. Predominant pathogens include Aspergillus and Fusarium, with yeast reported in a minority of cases. Resistance to common antifungal agents among filamentous fungi ...
Khan A, Olajide E, Friedrich M, Holt A, Goehring LS.Equid alphaherpesvirus 1 (EHV-1) is a highly contagious respiratory tract pathogen of horses, and infection may be followed by myeloencephalopathy or abortion. Surveillance and early detection have focused on PCR assays using less tolerated nasal swabs. Here, we assess non-invasive non-contact sampling techniques as surveillance tools in naturally equid gammaherpesvirus 2-shedding horses as surrogates for EHV-1. Horses were individually housed for 10 h periods on 2 consecutive days. Sampling included nasal swabs, nostril wipes, environmental swabs, droplet-catching devices, and air sampling. T...
Bell J, Raidal SL, Hughes KJ.Changes to the faecal microbiota of horses associated with administration of anthelmintic drugs is poorly defined. This study included horses with cyathostomin infection where susceptibility and resistance to oxfendazole and abamectin was known. This study assessed the changes to the faecal microbiota associated with administration of two different anthelmintics in this population. Twenty-four adult horses were included. Faecal egg counts were performed on all horses prior to random allocation into abamectin (n=8), oxfendazole (n=8) or Control groups (n=8) and at Day 14 post treatment. Faecal ...
Tijms MA, Snijder EJ.Non-structural protein 1 (nsp1), the N-terminal subunit of the replicase polyprotein of the arterivirus Equine arteritis virus (EAV), is essential for viral subgenomic mRNA synthesis, but fully dispensable for genome replication. However, at the molecular level, the role of nsp1 in EAV subgenomic mRNA synthesis is poorly understood. A yeast two-hybrid screen did not reveal interactions between EAV nsp1 and other viral non-structural proteins or the nucleocapsid protein, although both nsp1 and the nucleocapsid protein were found to form homomers. Subsequently, a yeast two-hybrid screen of a HeL...
Pepys MB, Baltz ML, Tennent GA, Kent J, Ousey J, Rossdale PD.A sensitive and precise immunoassay for equine serum amyloid A protein (SAA) was established and used to determine, for the first time, the circulating concentration of this protein in health and disease. As in other species, equine SAA was present only at trace levels in healthy animals but behaved as an extremely sensitive and rapidly responding acute phase reactant following most forms of tissue injury, infection and inflammation, objectively reflecting the extent and activity of disease. Measurements of SAA should make a significant contribution to diagnosis and management of viral and bac...
Chang YF, Ku YW, Chang CF, Chang CD, McDonough SP, Divers T, Pough M, Torres A.The objective of this study is to determine whether doxycycline, ceftiofur or tetracycline could be effectively used to treat equine Lyme disease. Ponies experimentally infected with Borrelia burgdorferi by tick exposure were treated with doxycycline, ceftiofur or tetracycline for 4 weeks (28 days). Doxycyline and ceftiofur treatment were inconsistent in eliminating persistent infection in this experimental model. However, tetracycline treatment seems to eliminate persistent infection. Although serum antibody levels to B. burgdorferi in all ponies declined gradually after antibiotic treatment,...
Oaks JL, McGuire TC, Ulibarri C, Crawford TB.The equine infectious anemia virus (EIAV) often results in lifelong subclinical infection following early episodes of clinical disease. To identify the cellular reservoirs of EIAV during subclinical infection, horses were infected with EIAV and allowed to develop subclinical infections. Horses with acute disease served as a basis for comparison. The tissue distribution, replication status, location of infected cells, and viral load were characterized by PCR for proviral DNA and reverse transcriptase PCR for viral RNA, in situ hybridization, and in situ PCR. Proviral DNA was widespread in tissu...
Troedsson MH.The objective of this article is to review the role of uterine defense mechanisms in natural resistance to chronic or persistent endometritis. A breakdown of uterine physical clearance mechanisms is currently believed to play a major role in susceptibility to persistent endometritis. Mares with increased susceptibility to persistent endometritis have impaired myometrial contractility in response to an acute inflammation, resulting in an accumulation of fluid and inflammatory products within the uterine lumen. The origin of this defect remains unknown. Recent studies have demonstrated that sper...
Arroyo LG, Rossi L, Santos BP, Gomez DE, Surette MG, Costa MC.The aim of this study was to compare the mucosal and luminal content microbiota of the cecum and colon of healthy and diarrheic horses. Marked differences in the richness and in the community composition between the mucosal and luminal microbiota of the cecum and large colon of horses with colitis were observed. Microbial dysbiosis occurs in horses with colitis at different levels of the intestinal tract, and microbiota composition is different between the mucosa and luminal content of diarrheic horses. The changes in some key taxa associated with dysbiosis in the equine intestinal microbiota,...
Li F, Puffer BA, Montelaro RC.Equine infectious anemia virus (EIAV) contains the simplest genome among lentiviruses in that it encodes only three putative regulatory genes (S1, S2, S3) in addition to the canonical gag, pol, and env genes, presumably reflecting its limited tropism to cells of monocyte/macrophage lineage. Tat and Rev functions have been assigned to S1 and S3, respectively, but the specific function for the S2 gene has yet to be determined. Thus, the function of S2 in virus replication in vitro was investigated by using an infectious molecular viral clone, EIAVUK. Various EIAVUK mutants lacking S2 were constr...
Tomlinson JE, Jager M, Struzyna A, Laverack M, Fortier LA, Dubovi E, Foil LD, Burbelo PD, Divers TJ, Van de Walle GR.Equine parvovirus-hepatitis (EqPV-H) has recently been associated with cases of Theiler's disease, a form of fulminant hepatic necrosis in horses. To assess whether EqPV-H is the cause of Theiler's disease, we first demonstrated hepatotropism by PCR on tissues from acutely infected horses. We then experimentally inoculated horses with EqPV-H and 8 of 10 horses developed hepatitis. One horse showed clinical signs of liver failure. The onset of hepatitis was temporally associated with seroconversion and a decline in viremia. Liver histology and in situ hybridization showed lymphocytic infiltrate...
Haenni M, Saras E, Ponsin C, Dahmen S, Petitjean M, Hocquet D, Madec JY.The objective of this study was to characterize ESBL-producing Enterobacter cloacae isolated from animals and to compare their clonal distribution with that of human-related isolates. Among 635 clinical E. cloacae from horses, dogs and cats collected in France between 2010 and 2013, 36 were resistant to ceftiofur as determined by disc diffusion. ESBL genes were identified by sequencing. Plasmids carrying ESBL-encoding genes were characterized by PCR-based replicon typing, S1-PFGE and Southern blotting. IncHI2 plasmids were subtyped using the plasmid double-locus sequence typing scheme and mult...
Wang H, Liu KJ, Sun YH, Cui LY, Meng X, Jiang GM, Zhao FW, Li JJ.Salmonella enterica subspecies enterica serovar abortus equi (S. abortus equi) is well known as the aetiological agent of equine abortion. However, abortion caused by S. abortus equi has not been previously described in donkeys. Objective: To investigate whether S. abortus equi was correlated with an abortion outbreak consisting of 61 abortions. Methods: Investigation of the clinical cases using pathoanatomical, bacteriological, serological and molecular approaches. Methods: Autopsies on nine aborted foetuses were performed. Tissue specimens from seven aborted foetuses and two mares were cu...
Hussey GS, Goehring LS, Lunn DP, Hussey SB, Huang T, Osterrieder N, Powell C, Hand J, Holz C, Slater J.Equine herpesvirus myeloencephalitis (EHM) remains one of the most devastating manifestations of equine herpesvirus type 1 (EHV-1) infection but our understanding of its pathogenesis remains rudimentary, partly because of a lack of adequate experimental models. EHV-1 infection of the ocular vasculature may offer an alternative model as EHV-1-induced chorioretinopathy appears to occur in a significant number of horses, and the pathogenesis of EHM and ocular EHV-1 may be similar. To investigate the potential of ocular EHV-1 as a model for EHM, and to determine the frequency of ocular EHV-1, our ...
Bargaoui R, Lecollinet S, Lancelot R.West Nile fever (WNF) is a viral disease of wild birds transmitted by mosquitoes. Humans and equids can also be affected and suffer from meningoencephalitis. In Tunisia, two outbreaks of WNF occurred in humans in 1997 and 2003; sporadic cases were reported on several other years. Small-scale serological surveys revealed the presence of antibodies against WN virus (WNV) in equid sera. However, clinical cases were never reported in equids, although their population is abundant in Tunisia. This study was achieved to characterize the nationwide serological status of WNV in Tunisian equids. In tota...
Relf VE, Morgan ER, Hodgkinson JE, Matthews JB.Few studies have described the combined effect of age, gender, management and control programmes on helminth prevalence and egg shedding in grazing equines. Here, fecal samples collected from 1221 Thoroughbred horses, residing at 22 studs in the UK, were analysed. The distribution of strongyle eggs amongst individuals in relation to age, gender and management practices was investigated. Fecal worm egg counts (FWECs), described as the number of eggs per gramme (epg) of feces, were determined using a modification of the salt flotation method. The FWEC prevalence (mean%) of strongyles, Parascaris...
Tessier L, Côté O, Clark ME, Viel L, Diaz-Méndez A, Anders S, Bienzle D.Severe equine asthma is a naturally occurring lung inflammatory disease of mature animals characterized by neutrophilic inflammation, bronchoconstriction, mucus hypersecretion and airway remodeling. Exacerbations are triggered by inhalation of dust and microbial components. Affected animals eventually are unable of aerobic performance. In this study transcriptomic differences between asthmatic and non-asthmatic animals in the response of the bronchial epithelium to an inhaled challenge were determined. Results: Paired endobronchial biopsies were obtained pre- and post-challenge from asthmatic ...
Amaya M, Keck F, Lindquist M, Voss K, Scavone L, Kehn-Hall K, Roberts B, Bailey C, Schmaljohn C, Narayanan A.Many viruses have been implicated in utilizing or modulating the Ubiquitin Proteasome System (UPS) to enhance viral multiplication and/or to sustain a persistent infection. The mosquito-borne Venezuelan equine encephalitis virus (VEEV) belongs to the Togaviridae family and is an important biodefense pathogen and select agent. There are currently no approved vaccines or therapies for VEEV infections; therefore, it is imperative to identify novel targets for therapeutic development. We hypothesized that a functional UPS is required for efficient VEEV multiplication. We have shown that at non-tox...
Allen G, Yeargan M, Costa LR, Cross R.An experimental system that permits sensitive and reproducible detection of equine herpesvirus 1 (EHV-1)-specific cytotoxic T-lymphocyte (CTL) activity in the horse was developed. Peripheral blood mononuclear cells (PBMC) collected from immune horses were restimulated in vitro by culture with live EHV-1. Cytotoxic activity against virus-infected, pokeweed mitogen-stimulated lymphoblast targets was assessed in a 4-h 51Cr release assay. The optimal conditions for in vitro stimulation of equine memory CTLs and for preparation of EHV-1-infected target cells expressing viral antigens were systemati...
Hoshino Y, Wyatt RG, Greenberg HB, Kalica AR, Flores J, Kapikian AZ.A rotavirus, designated as the H-1 strain, was isolated from a diarrheic foal in primary African green monkey kidney cells and MA104 cells. This cell culture-adapted strain hemagglutinated erythrocytes of human group O, rhesus monkeys, guinea pigs, and sheep. It was found to be similar, if not identical, to porcine rotaviruses (strains OSU, EE, and A-580) by plaque reduction neutralization and hemagglutination inhibition tests, and, in addition, it was found to belong to subgroup 1. This equine rotavirus has an RNA electrophoretic migration pattern which was distinct from those of the three st...
Freeman K, Woods E, Welsby S, Percival SL, Cochrane CA.Evidence of biofilms in human chronic wounds are thought to be responsible for preventing healing in a timely manner. However, biofilm evidence in horse wounds has not yet been documented. Consequently, this study aimed to determine whether biofilms could be detected in wounds, and to investigate the microbiology of chronic wounds in horses. Prior to analysis, wound surfaces were irrigated with 5 mL of sterile saline to remove debris. All wounds were swabbed twice (1 cm2 area) using sterile cotton-tipped swabs. In addition to this, 2 tissue biopsies were taken to investigate evidence of biofil...
Malalana F, Stylianides A, McGowan C.Equine recurrent uveitis (ERU) is a spontaneous disease characterised by repeated episodes of intraocular inflammation. The epidemiology of ERU has not been fully elucidated, but the condition appears to be much more common in horses than is recurrent uveitis in humans, especially in certain breeds and geographical regions. Both humans and horses show a similarly altered immune response and a marked autoimmune response as the primary disease pathophysiology. However, an inciting cause is not always clear. Potential inciting factors in horses include microbial agents such as Leptospira spp. Mic...
Pusterla N, Vin R, Leutenegger C, Mittel LD, Divers TJ.Equine coronavirus (ECoV) is an emerging virus associated clinically and epidemiologically with fever, depression, anorexia and less frequently colic and diarrhoea in adult horses. Sporadic cases and outbreaks have been reported with increased frequency since 2010 from Japan, the USA and more recently from Europe. A faeco-oral transmission route is suspected and clinical or asymptomatic infected horses appear to be responsible for direct and indirect transmission of ECoV. A presumptive clinical diagnosis of ECoV infection may be suggested by clinical presentation, haematological abnormalities ...
Soares SC, Trost E, Ramos RT, Carneiro AR, Santos AR, Pinto AC, Barbosa E, Aburjaile F, Ali A, Diniz CA, Hassan SS, Fiaux K, Guimarães LC....Corynebacterium pseudotuberculosis is the causative agent of several veterinary diseases in a broad range of economically important hosts, which can vary from caseous lymphadenitis in sheep and goats (biovar ovis) to ulcerative lymphangitis in cattle and horses (biovar equi). Existing vaccines against C. pseudotuberculosis are mainly intended for small ruminants and, even in these hosts, they still present remarkable limitations. In this study, we present the complete genome sequence of C. pseudotuberculosis biovar equi strain 258, isolated from a horse with ulcerative lymphangitis. The genome...
Bogaert L, Martens A, Van Poucke M, Ducatelle R, De Cock H, Dewulf J, De Baere C, Peelman L, Gasthuys F.Bovine papillomavirus (BPV), the causative agent of papillomas in cattle, has been shown to play a major role in the pathogenesis of equine sarcoids in horses. BPV has also been detected occasionally in normal equine skin. In this study, presence and activity of BPV in normal skin and peripheral blood of 4 groups of horses were evaluated: sarcoid-affected horses, horses living in contact with sarcoid-affected horses, horses living in contact with papilloma-affected cattle and control horses. From each horse, 3 samples on 4 locations were collected: a swab of the intact skin surface and both a ...
Fetene E, Leta S, Regassa F, Büscher P.Trypanosomosis caused by Trypanosoma vivax is one of the diseases threatening the health and productivity of livestock in Africa and Latin America. Trypanosoma vivax is mainly transmitted by tsetse flies; however, the parasite has also acquired the ability to be transmitted mechanically by hematophagous dipterans. Understanding its distribution, host range and prevalence is a key step in local and global efforts to control the disease. Methods: The study was conducted according to the methodological recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIS...
Cook RF, Cook SJ, Li FL, Montelaro RC, Issel CJ.A single-tube reverse transcriptase-polymerase chain reaction (RT-PCR) using a fluorogenic real-time PCR detection method is described for the quantitation of equine infectious anemia virus (EIAV) RNA in the plasma of equids. To compensate for variations inherent in sample preparation a multiplex real-time RT-PCR system was developed that permitted the simultaneous calculation of the nucleic acid recovery rate along with the copy number of viral RNA molecules. Detection of EIAV RNA was linear from 10(9) to 10(1) molecules with intra- and inter-assay variability of less than 1% at 10(8), 10(6),...
Mossel EC, Ledermann JP, Phillips AT, Borland EM, Powers AM, Olson KE.Western equine encephalitis virus (WEEV) is a naturally occurring recombinant virus derived from ancestral Sindbis and Eastern equine encephalitis viruses. We previously showed that infection by WEEV isolates McMillan (McM) and IMP-181 (IMP) results in high (∼90-100%) and low (0%) mortality, respectively, in outbred CD-1 mice when virus is delivered by either subcutaneous or aerosol routes. However, relatively little is known about specific virulence determinants of WEEV. We previously observed that IMP infected Culex tarsalis mosquitoes at a high rate (app. 80%) following ingestion of an in...
Bingham AM, Burkett-Cadena ND, Hassan HK, McClure CJ, Unnasch TR.Studies investigating winter transmission of Eastern equine encephalitis virus (EEEV) were conducted in Hillsborough County, Florida. The virus was detected in Culiseta melanura and Anopheles quadrimaculatus in February 2012 and 2013, respectively. During the winter months, herons were the most important avian hosts for all mosquito species encountered. In collections carried out in the summer of 2011, blood meals taken from herons were still common, but less frequently encountered than in winter, with an increased frequency of mammalian- and reptile-derived meals observed in the summer. Four ...
Grause JF, Ueti MW, Nelson JT, Knowles DP, Kappmeyer LS, Bunn TO.Theileria equi, one of the causative agents of equine piroplasmosis, is endemic in many regions of the world but is considered a 'foreign' animal disease in the USA. In an effort to prevent the importation of T. equi, stringent serological screening of horses is practiced prior to entry to the USA. Current regulatory options available where horses are found to be infected include permanent quarantine with or without chemotherapy, repatriation, or euthanasia. Chemotherapeutics that eliminate infection and subsequently transmission risk are critical in the management of infected horses. In this ...
Lin YZ, Sun LK, Zhu DT, Hu Z, Wang XF, Du C, Wang YH, Wang XJ, Zhou JH.Human schlafen11 is a novel restriction factor for HIV-1 based on bias regarding relative synonymous codon usage (RSCU). Here, we report the cloning of equine schlafen11 (eSLFN11) and the characteristics of its role in restricting the production of equine infectious anemia virus (EIAV), a retrovirus similar to HIV-1. Overexpression of eSLFN11 inhibited EIAV replication, whereas knockdown of endogenous eSLFN11 by siRNA enhanced the release of EIAV from its principal target cell. Notably, although eSLFN11 significantly suppressed expression of viral Gag protein and EIAV release into the culture ...
Medina-Torres CE, Weese JS, Staempfli HR.Fecal samples were collected to establish the apparent prevalence of Clostridium difficile shedding in Standardbred and Thoroughbred racehorses housed at 4 racetracks and 2 breeding facilities, and in horses admitted to a referral large animal clinic. Forty-one (7.59%) of 540 racetrack horses, seven (5.83%) of 120 breeding farm horses, and four (4.88%) out of 82 horses admitted to the referral clinic were culture-positive for C. difficile. An overall fecal culture prevalence of 7.01% for C. difficile was identified in 742 fecal samples. PCR-ribotyping and toxin gene identification was performe...
Duncan JL, Pirie HM.The clinical signs, pathology and clinical pathology associated with single experimental infections of Strongylus vulgaris in worm-free pony foals are described. The major clinical signs which became apparent in the infected foals during the first three weeks were pyrexia, anorexia, dullness and abdominal pain. Within the first two weeks of infection lesions were confined to the intestine and terminal branches of the intestinal arteries and consisted of mucosal, submucosal and serosal haemorrhage together with arteritis of submucosal and serosal arteries and also a marked inflammatory reaction...
