Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Molazadeh S, Tukmechi A, Hadian M, Dalir-Naghadeh B.This study aimed to determine the prevalence and phylogenetic analysis of Ehrlichia spp. in horses and dogs in Iran. Blood samples were collected from 400 animals, including 200 horses and 200 dogs, from five different provinces in Iran. Polymerase chain reaction (PCR) was used to detect Ehrlichia spp. based on amplification of the 16S rRNA gene. The semi-nested PCR method was used to amplify the dsb, TRP36, and gltA genes. The results showed that 4.5 % of the samples (3 % horses and 6 % dogs) were positive for Ehrlichia sp. The highest prevalence was observed in Kerman and Khuzestan, while th...
Hudson AR, McGregor BL, Shults P, England M, Silbernagel C, Mayo C, Carpenter M, Sherman TJ, Cohnstaedt LW.Orbiviruses are of significant importance to the health of wildlife and domestic animals worldwide; the major orbiviruses transmitted by multiple biting midge (Culicoides) species include bluetongue virus, epizootic hemorrhagic disease virus, and African horse sickness virus. The viruses, insect vectors, and hosts are anticipated to be impacted by global climate change, altering established Orbivirus epidemiology. Changes in global climate have the potential to alter the vector competence and extrinsic incubation period of certain biting midge species, affect local and long-distance dispersal ...
Hébert L, Froger D, Madeline A, Lecouturier F, Lemans C, Zientara S.Dourine is a sexually transmitted parasitic disease affecting equids. Its causative agent is referred to as and the prescribed serodiagnosis method is the complement fixation test (CFT). In the context of our European Reference Laboratory mandate for equine diseases (excluding African horse sickness), we organised dourine CFT inter-laboratory proficiency tests (ILPTs) in 2015, 2018 and 2022 to evaluate the performance of the European Union network of National Reference Laboratories (NRLs) for dourine. ILPT panels were composed of horse sera with or without antibodies against spp. originating...
Pan J, Ji L, Wu H, Wang X, Wang Y, Wu Y, Yang S, Shen Q, Liu Y, Zhang W, Zhang K, Shan T.Mammals are potential hosts for many infectious diseases. However, studies on the viral communities of herbivorous mammals in the Northwest Plateau are limited. Here, we studied the viral communities of herbivorous mammals in the Northwest Plateau using virus metagenomic analysis to analyze and compare the viral community composition of seven animal species. Results: By library construction and next-generation sequencing, contigs and singlets reads with similar viral sequences were classified into 24 viral families. Analyzed from the perspective of sampling areas, the virus community compositi...
Aida H, Foreman JH, Ochi A, Takizawa Y, Yamanaka T.Equine piroplasmosis is an infectious disease caused by Babesia caballi and Theileria equi. A competition horse that had been imported to the Equestrian Park for the Tokyo 2020 Olympic Games and had a fever over 40°C and severe anemia was diagnosed with equine piroplasmosis by blood smear and direct polymerase chain reaction (PCR) tests for Theileria equi. Treatment with protozoan anthelmintics and whole blood transfusion diminished the fever, improved the anemia, and allowed the horse to return home safely. Preparation for routine cases of this infection should include the development of a s...
subsp. is a rare etiologic agent of bacterial meningitis in humans. The disease is a zoonotic infection and is transmitted through close contact with domestic animals, mainly horses. Only 37 cases of meningitis have been reported in the literature until July 2023. The aim of this study is to present a rare clinical case of -related meningitis in a human immunodeficiency virus (HIV)-positive patient and analyze the literature. We present a 23-year-old horse breeder patient with advanced immunosuppression due to acquired immunodeficiency syndrome (AIDS) and meningitis, admitted at the Clinic...
Birckhead EM, Das S, Tidd N, Raidal SL, Raidal SR.Septic synovitis and peritonitis are routinely diagnosed in horses based on clinical examination findings and laboratory assessment of synoviocentesis and abdominocentesis samples, respectively. Diagnosis is difficult in some cases because of an overlap in laboratory results for septic and non-septic inflammation. Neutrophil extracellular trap (NET) formation is part of the innate immune response against pathogens. Identifying and quantifying NETs, which have not been explored in clinical samples from horses with septic synovitis and peritonitis, to our knowledge, may be helpful in detecting i...
Madrigal-Valencia TL, Saavedra-Montañez M, Pérez-Torres A, Hernández J, Segalés J, Hernández YD, Candanosa-Aranda IE, Pérez-Guiot A....Ovine gammaherpesvirus 2 (OvHV-2), a member of the genus Macavirus, causes sheep-associated malignant catarrhal fever (SA-MCF), a fatal lymphoproliferative disease affecting a wide variety of ungulates in addition to horses. This study described an outbreak of SA-MCF in Mexico and the identification of the OvHV-2 virus in primary rabbit testis cultures through the generation of intranuclear inclusion bodies, syncytia, immunofluorescence (IF), immunocytochemistry (ICC), immunohistochemistry (IHC), endpoint polymerase chain reaction (PCR), and partial sequencing of the ORF75 gene. The animals in...
Alshammari A, Gattan HS, Marzok M, Salem M, Al-Jabr OA, Selim A.Fasciola hepatica is a trematode parasite that affects wide range of mammalian hosts including horses. There are no epidemiological data on fasciolosis in Egyptian horses. Hence, the present study aimed to evaluate the seroprevalence of F. hepatica in horses using ELISA as well as assess the associated risk factors for fasciolosis infection. A total of 400 sera samples of horses from three Egyptian governorates were examined. The overall seroprevalence rate in horses was 13% and the disease was more prevalent in Qalubia (14.17%) and Gharbia (16.67%) which are located at Nile Delta. The likelih...
Virtanen J, Hautaniemi M, Dutra L, Plyusnin I, Hautala K, Smura T, Vapalahti O, Sironen T, Kant R, Kinnunen PM.We report a sequencing protocol and 121-kb poxvirus sequence from a clinical sample from a horse in Finland with dermatitis. Based on phylogenetic analyses, the virus is a novel parapoxvirus associated with a recent epidemic; previous data suggest zoonotic potential. Increased awareness of this virus and specific diagnostic protocols are needed.
Rockx B, Mire CE.Henipaviruses are emerging zoonotic viruses that can cause outbreaks of severe respiratory and neurological disease in humans and animals such as horses. The mechanism by which these viruses can cause disease remain largely unknown and to date there are no therapeutics or vaccines approved for use in humans. Nipah virus is listed on the World Health Organization R & D Blueprint list of epidemic threats. In order to advance the availability of effective therapeutics and vaccines and medicines that can be used to save lives and avert large scale crises, animal models are required which recap...
Pelkola K, Heinikainen S, Pohjanvirta T.In Finland, Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), was first detected in 1992. The aim of this study was to genotype Finnish T. equigenitalis isolates to investigate the epidemiology of the infection in the Finnish horse population. A total of 34 T. equigenitalis isolates from 24 horses obtained during 1992-2021 were subjected to whole genome sequencing (WGS) and subsequent local ad hoc core genome multi-locus sequence typing (cgMLST) targeting 1259 loci. Classical MLST profiles were extracted from the whole-genome sequence data. Three novel MLST ty...
Maggi R, De Paolis L, De Santis D, Vellone VG, De Ciucis CG, Fruscione F, Mazzocco K, Ghelardi A, Marruchella G, Razzuoli E.Papillomas are benign epithelial lesions protruding on the epithelial surfaces as finger-like or warty projections. These lesions are often caused by papillomavirus (PV) infection. Congenital papillomas have been reported in foals. However, to date, no evidence of PV infection has been provided. In the present paper, we describe the main clinical-pathological features of a congenital papilloma observed in a foal. In addition, biomolecular tests demonstrated BPV1 infection in the case under study. Such data stimulate further investigations, even on archived samples, aiming to clarifying the eti...
Knox A, Zerna G, Beddoe T.Horses play an important role throughout the world, whether for work, culture, or leisure, providing an ever-growing significant contribution to the economy. The increase in importation and movement of horses, both nationally and internationally, has inevitably allowed for the global equine industry to grow. Subsequently, however, the potential for transmission of fatal equine bacterial diseases has also escalated, and devasting outbreaks continue to occur. To prevent such events, disease surveillance and diagnosis must be heightened throughout the industry. Current common, or "gold-standard" ...
Stummer M, Frisch V, Glitz F, Hinney B, Spergser J, Krücken J, Diekmann I, Dimmel K, Riedel C, Cavalleri JV, Rümenapf T, Joachim A, Lyrakis M....Acute abdominal pain (colic) is one of the major equine health threats worldwide and often necessitates intensive veterinary medical care and surgical intervention. Equine coronavirus (ECoV) infections can cause colic in horses but are rarely considered as a differential diagnosis. To determine the frequency of otherwise undetected ECoV infections in horses with acute colic, fresh fecal samples of 105 horses with acute colic and 36 healthy control horses were screened for viruses belonging to the species by RT-PCR as well as for gastrointestinal helminths and bacteria commonly associated with...
Nguyen HN, Smith ME, Hayoun MA.Glanders is an infectious disease caused by Burkholderia mallei, a gram-negative aerobic nonmotile bacterium. Melioidosis is an infectious disease caused by Burkholderia pseudomallei, a gram-negative aerobic, motile bacterium. The two bacteria are closely related, and both can cause disease in animals and humans. Historically, glanders was a common disease of horses, donkeys, and mules. Melioidosis was first described as a case series of 38 patients in Rangoon, Burma, by pathologist Alfred Whitmore in 1912.
Khaled MM, Ibrahium AM, Abdelgalil AI, El-Saied MA, El-Bably SH.Peripheral nerve damage mainly resulted from traumatic or infectious causes; the main signs of a damaged nerve are the loss of sensory and/or motor functions. The injured nerve has limited regenerative capacity and is recovered by the body itself, the recovery process depends on the severity of damage to the nerve, nowadays the use of stem cells is one of the new and advanced methods for treatment of these problems. Following our review, data are collected from different databases "Google scholar, Springer, Elsevier, Egyptian Knowledge Bank, and PubMed" using different keywords such as Periphe...
Uchida-Fujii E, Niwa H, Senoh M, Kato H, Kinoshita Y, Mita H, Ueno T.We encountered 34 Clostridioides difficile (C. difficile) infection (CDI) cases among Thoroughbred horses in Japan from 2010 to 2021. Among them, 79.4% (27/34) either died or were euthanised. The risk factors associated with CDI and mortality among Japanese Thoroughbred horses remain unclear. We used genetic methods to examine C. difficile strains and their relationships with prognosis. Twenty-two (64.7%) cases were hospitalised at the onset of colitis. Outcomes were balanced for hospitalisation rates at the onset of colitis. The mortality rates of cases treated with metronidazole (65.0%) were...
Cardo MV, Vezzani D.Targeted vector surveillance informed by data on mosquito biting patterns can help limit arboviral zoonotic diseases. To characterise host-biting networks in rural and urban equestrian facilities from temperate Argentina, adult resting mosquitoes were collected (December 2018-April 2019) with a battery-powered aspirator. Engorged females were sorted to species, and their blood source was identified using molecular techniques. Bipartite network analysis was performed for rural and urban matrices. A total of 177 bloodmeals from 11 mosquito species of Aedes and Culex were identified, with seven m...
Levasseur A, Arsenault J, Paré J.West Nile virus (WNV) became notifiable in horses in 2003 in Canada and has been reported every year since. The objective of this study was to describe the spatiotemporal distribution of WNV in horses between 2003 and 2020 in Canada. Methods: The 848 symptomatic and laboratory-confirmed WNV cases in horses reported to the Canadian Food Inspection Agency between 2003 and 2020. Methods: Canada was divided into eastern and western regions for analysis. For each case, location and date of notification were captured. Triennial maps were made to describe the spatiotemporal distribution and expansion...
Bohlman T, Waddell H, Schumaker B.The occurrence of zoonotic infections following an animal exposure continues to be an important consideration for all patients, especially those within agricultural communities. Streptococcus equi subspecies equi (S. equi subsp. equi) is a bacteria known to cause a common infection called 'Strangles' in horses. This article highlights a new case of pneumonia and bacteremia in a patient caused by S. equi subsp. equi following strangles exposure in a horse. Rarely has there been reported horse to human transmission of subsp. equi. Methods: A 70-year-old woman attended a rural emergency departmen...
Lightbody KL, Austin A, Lambert PA, von Samson-Himmelstjerna G, Jürgenschellert L, Krücken J, Nielsen MK, Sallé G, Reigner F, Donnelly CG....Cyathostomins are ubiquitous equine nematodes. Infection can result in larval cyathostominosis due to mass larval emergence. Although faecal egg count (FEC) tests provide estimates of egg shedding, these correlate poorly with burden and provide no information on mucosal/luminal larvae. Previous studies describe a serum IgG(T)-based ELISA (CT3) that exhibits utility for detection of mucosal/luminal cyathostomins. Here, this ELISA is optimised/validated for commercial application using sera from horses for which burden data were available. Optimisation included addition of total IgG-based calibr...
Hepworth-Warren KL, Estell K, Cowles B, Amodie D, Crisman M.Serum amyloid A (SAA) is a major acute phase protein in horses which could be a useful tool for assessing clinical response to treatment of bacterial pneumonia in adult horses.
Amory H, Cesarini C, De Maré L, Loublier C, Moula N, Detilleux J, Saulmont M, Garigliany MM, Lecoq L.The objective of this retrospective study was to evaluate the clinical significance of fecal quantitative real-time polymerase chain reaction (qPCR) results when taking the cycle threshold values (Ct) into account. The study included 120 qPCR-positive fecal samples obtained from 88 hospitalized horses over a 2-year period. The mean Ct of the qPCR test was evaluated in regard to (1) clinical outcome and (2) systemic inflammatory response syndrome (SIRS) status (no SIRS, moderate SIRS, or severe SIRS) of the sampled horses. An ROC analysis was performed to establish the optimal cut-off Ct valu...
Rule EK, Boyle AG, Stefanovski D, Anis E, Linton J, Lorello O.Equine granulocytic anaplasmosis (EGA) is a common disease in adult horses, but clinical disease in foals is rarely reported. The relationship between equine maternal and neonatal antibodies to Anaplasma phagocytophilum is unclear. Objective: That mares in an endemic region would be seropositive for A. phagocytophilum and that mare and foal serum IgG concentrations for A. phagocytophilum would correlate. Additionally, we hypothesized that foal IgG concentrations for A. phagocytophilum acquired by passive immunity would decline by 6 months of age. Methods: Twenty-two healthy mare-foal pairs. ...
El-Hage C, Legione A, Devlin J, Hughes K, Jenkins C, Gilkerson J. is an important zoonotic pathogen. Although primarily a pathogen of birds, from which infection can spillover into humans and other mammalian hosts, the importance of as a cause of equine reproductive loss and the risk of infection to humans in contact with infected horses are increasingly being recognised in Australia and elsewhere. Despite the risks to both human and equine health, infection in horses is incompletely understood. This study aimed to update and summarise cases of equine psittacosis in Australia in the period 2018-2022, thus addressing a knowledge gap relating to recent case...
Carossino M, Balasuriya UBR, Thieulent CJ, Barrandeguy ME, Vissani MA, Parreño V.Equine rotavirus A (ERVA) is the leading cause of diarrhea in foals, with G3P[12] and G14P[12] genotypes being the most prevalent. Recently, equine G3-like RVA was recognized as an emerging infection in children, and a group B equine rotavirus (ERVB) was identified as an emergent cause of foal diarrhea in the US. Thus, there is a need to adapt molecular diagnostic tools for improved detection and surveillance to identify emerging strains, understand their molecular epidemiology, and inform future vaccine development. We developed a quadruplex TaqMan RT-qPCR assay for differentiation of ERVA an...
Matas Riera M, Cardenas Nadal M, Martínez-Sogues L, Ferrer L.Dermatological clinical signs have been seldom reported in the literature secondary to equine leishmaniasis. This case depicts the clinical signs, treatment, and outcome of a young horse with a pink, elevated lesion on the ventromedial quadrant of the cornea. A corneal cytology was performed and revealed the presence of leishmania amastigotes reaching the diagnosis of keratitis secondary to leishmania. Surgical resection was recommended but the owner declined the procedure, and the lesion was treated with a topical antimonial for 6 weeks. The lesion reduced remarkably during the first weeks ...
Liu L, Yu W, Cai K, Ma S, Wang Y, Ma Y, Zhao H. () is a zoonotic opportunistic pathogen that can cause life-threatening infections. The rapid evolution of multidrug-resistant and the fact that there is no currently licensed effective vaccine against warrant the need for vaccine development. Reverse vaccinology (RV), which involves screening a pathogen's entire genome and proteome using various web-based prediction tools, is considered one of the most effective approaches for identifying vaccine candidates. Here, we performed a pangenome analysis to determine the core proteins of . We then used the RV approach to examine the subcellular l...
Smit H, Gaastra W, Kamerling JP, Vliegenthart JF, de Graaf FK.The erythrocyte receptor for Escherichia coli K99 fimbrial adhesin was isolated from equine erythrocytes and characterized as Neu5Gc-alpha(2----3)-Galp-beta(1----4)-GLcp-beta(1----1)-Ceramide. This glycolipid acted as the receptor for K99 by four different experimental approaches: inhibition of equine erythrocyte hemagglutination by preincubation of K99-positive bacteria or purified K99 fimbriae with the isolated glycolipid; inhibition of attachment of K99-positive bacteria to porcine intestinal epithelial cells in the presence of the isolated glycolipid; induction of binding of K99-positive b...
Walter S, Rasche A, Moreira-Soto A, Pfaender S, Bletsa M, Corman VM, Aguilar-Setien A, García-Lacy F, Hans A, Todt D, Schuler G....The hepatitis C virus (HCV) is a major human pathogen. Genetically related viruses in animals suggest a zoonotic origin of HCV. The closest relative of HCV is found in horses (termed equine hepacivirus [EqHV]). However, low EqHV genetic diversity implies relatively recent acquisition of EqHV by horses, making a derivation of HCV from EqHV unlikely. To unravel the EqHV evolutionary history within equid sister species, we analyzed 829 donkeys and 53 mules sampled in nine European, Asian, African, and American countries by molecular and serologic tools for EqHV infection. Antibodies were found in...
Beck C, Lowenski S, Durand B, Bahuon C, Zientara S, Lecollinet S.West Nile Fever is a zoonotic disease caused by a mosquito-borne flavivirus, WNV. By its clinical sensitivity to the disease, the horse is a useful sentinel of infection. Because of the virus' low-level, short-term viraemia in horses, the primary tools used to diagnose WNV are serological tests. Inter-laboratory proficiency tests (ILPTs) were held in 2010 and 2013 to evaluate WNV serological diagnostic tools suited for the European network of National Reference Laboratories (NRLs) for equine diseases. These ILPTs were designed to evaluate the laboratories' and methods' performances in detectin...
Poissant J, Gavriliuc S, Bellaw J, Redman EM, Avramenko RW, Robinson D, Workentine ML, Shury TK, Jenkins EJ, McLoughlin PD, Nielsen MK, Gilleard JS.Horses are ubiquitously infected by a diversity of gastro-intestinal parasitic helminths. Of particular importance are nematodes of the family Strongylidae, which can significantly impact horse health and performance. However, knowledge about equine strongyles remains limited due to our inability to identify most species non-invasively using traditional morphological techniques. We developed a new internal transcribed spacer 2 (ITS2) DNA metabarcoding 'nemabiome' assay to characterise mixed strongyle infections in horses and assessed its performance by applying it to pools of infective larvae ...
Nielsen MK.Anthelmintic resistance is reported in equine nematodes with increasing frequency in recent years, and no new anthelmintic classes have been introduced during the past 40 years. This manuscript reviews published literature describing anthelmintic resistance in cyathostomins, Parascaris spp., and Oxyuris equi with special emphasis on larvicidal efficacy against encysted cyathostomin larvae and strongylid egg reappearance periods (ERP). Resistance to benzimidazoles and pyrimidines is highly prevalent in cyathostomin populations around the world, and macrocyclic lactone resistance has been docume...
Moodley A, Stegger M, Bagcigil AF, Baptiste KE, Loeffler A, Lloyd DH, Williams NJ, Leonard N, Abbott Y, Skov R, Guardabassi L.Region X of the protein A gene (spa) was sequenced from methicillin-resistant Staphylococcus aureus (MRSA) isolates originating from animals, humans and the environment at veterinary hospitals in the UK and Ireland. MRSA transmission between animals and veterinary staff was assessed on the basis of spa typing, PFGE and epidemiological data. Methods: MRSA isolates from dogs (n = 27), horses (n = 9), cats (n = 6), staff (n = 22) and environmental surfaces (n = 3) were analysed by PFGE and spa typing. Known contacts between human and animal MRSA carriers were ascertained from the veterinary hospi...
Dobbe JC, van der Meer Y, Spaan WJ, Snijder EJ.The recent development of arterivirus full-length cDNA clones makes possible the construction of chimeric arteriviruses for fundamental and applied studies. Using an equine arteritis virus (EAV) infectious cDNA clone, we have engineered chimeras in which the ectodomains of the two major envelope proteins, the glycoprotein GP(5) and the membrane protein M, were replaced by sequences from envelope proteins of related and unrelated RNA viruses. Using immunofluorescence microscopy, we monitored the transport of the hybrid GP(5) and M proteins to the Golgi complex, which depends on their heterodime...
Woodward AL, Rash AS, Blinman D, Bowman S, Chambers TM, Daly JM, Damiani A, Joseph S, Lewis N, McCauley JW, Medcalf L, Mumford J, Newton JR, Tiwari A....Equine influenza viruses are a major cause of respiratory disease in horses worldwide and undergo antigenic drift. Several outbreaks of equine influenza occurred worldwide during 2010-2012, including in vaccinated animals, highlighting the importance of surveillance and virus characterisation. Virus isolates were characterised from more than 20 outbreaks over a 3-year period, including strains from the UK, Dubai, Germany and the USA. The haemagglutinin-1 (HA1) sequence of all isolates was determined and compared with OIE-recommended vaccine strains. Viruses from Florida clades 1 and 2 showed c...
Blackmore CG, Stark LM, Jeter WC, Oliveri RL, Brooks RG, Conti LA, Wiersma ST.After West Nile virus (WNV) was first detected in Florida in July 2001, intensive surveillance efforts over the following five months uncovered virus activity in 65 of the state's 67 counties with 1,106 wild birds, 492 horses, 194 sentinel chickens, and 12 people found infected with the virus. Thirteen of 28 mosquito isolations came from Culex mosquitoes. As seen in the northeastern United States, wild bird mortality was the most sensitive surveillance method. However, unlike the predominantly urban 1999 and 2000 epizootics, the Florida transmission foci were rural with most activity detected ...
Rikihisa Y, Perry BD, Cordes DO.Potomac horse fever is characterized by fever, anorexia, leukopenia, profuse watery diarrhea, dehydration, and high mortality. An ultrastructural investigation was made to search for any unusual microorganisms in the digestive system, lymphatic organs, and blood cells of ponies that had developed clinical signs after transfusion with whole blood from horses naturally infected with Potomac horse fever. A consistent finding was the presence of rickettsial organisms in the wall of the intestinal tract of these ponies. The organisms were found mostly in the wall of the large colon, but fewer organ...
Almazán C, Scimeca RC, Reichard MV, Mosqueda J.Babesia and Theileria are apicomplexan parasites that cause established and emerging diseases in humans, domestic and wild animals. These protozoans are transmitted by Ixodid ticks causing babesiosis or theileriosis, both characterized by fever, hemolytic anemia, jaundice, and splenomegaly. In North America (NA), the most common species affecting humans is B. microti, which is distributed in the Northeastern and Upper Midwestern United States (US), where the tick vector Ixodes scapularis is established. In livestock, B. bovis and B. bigemina are the most important pathogens causing bovine babe...
Tanaka T, Kasai H, Yamashita A, Okuyama-Dobashi K, Yasumoto J, Maekawa S, Enomoto N, Okamoto T, Matsuura Y, Morimatsu M, Manabe N, Ochiai K....Equine hepacivirus (EHcV) has been identified as a closely related homologue of hepatitis C virus (HCV) in the United States, the United Kingdom, and Germany, but not in Asian countries. In this study, we genetically and serologically screened 31 serum samples obtained from Japanese-born domestic horses for EHcV infection and subsequently identified 11 PCR-positive and 7 seropositive serum samples. We determined the full sequence of the EHcV genome, including the 3' untranslated region (UTR), which had previously not been completely revealed. The polyprotein of a Japanese EHcV strain showed ap...
Ledizet M, Kar K, Foellmer HG, Wang T, Bushmich SL, Anderson JF, Fikrig E, Koski RA.West Nile (WN) virus is a flavivirus that first appeared in North America in 1999. Since then, more than 600 human deaths and 22,000 equine infections have been attributed to the virus in the United States. We expressed a truncated form of WN virus envelope (E) protein in Drosophila S2 cells. This soluble recombinant E protein was recognized by antibodies from naturally infected horses, indicating that it contains native epitopes. Mice and horses produced high-titer antibodies when immunized with recombinant E protein combined with aluminum hydroxide. Immunized mice were resistant to challenge...
Di Gennaro A, Lorusso A, Casaccia C, Conte A, Monaco F, Savini G.A serum neutralization assay (SN) was compared with the official plaque reduction neutralization test for the quantitation of West Nile virus antibodies. A total of 1,348 samples from equid sera and 38 from human sera were tested by these two methods. Statistically significant differences were not observed, thus supporting the use of SN for routine purposes.
van Eeden C, Williams JH, Gerdes TG, van Wilpe E, Viljoen A, Swanepoel R, Venter M.To determine which agents cause neurologic disease in horses, we conducted reverse transcription PCR on isolates from of a horse with encephalitis and 111 other horses with acute disease. Shuni virus was found in 7 horses, 5 of which had neurologic signs. Testing for lesser known viruses should be considered for horses with unexplained illness.
Ueti MW, Palmer GH, Kappmeyer LS, Statdfield M, Scoles GA, Knowles DP.The protozoan parasite Babesia equi replicates within erythrocytes. During the acute phase of infection, B. equi can reach high levels of parasitemia, resulting in a hemolytic crisis. Horses that recover from the acute phase of the disease remain chronically infected. Subsequent transmission is dependent upon the ability of vector ticks to acquire B. equi and, following development and replication, establishment of B. equi in the salivary glands. Although restriction of the movement of chronically infected horses with B. equi is based on the presumption that ticks can acquire and transmit the ...
Kydd JH, Smith KC, Hannant D, Livesay GJ, Mumford JA.Twelve adult ponies and 2 conventional foals were exposed intranasally to EHV-1, strain Ab4 (TCID50 10(-6.6) and samples of respiratory tract associated lymphoid tissues were recovered between 12 h and 13 days after infection. Infectious virus was detected in tissue homogenates using susceptible cell monolayers and expression of viral antigens was monitored using indirect immunoperoxidase histochemistry on paraffin sections. The results showed both infectious EHV-1 and viral antigens in respiratory tract associated lymph nodes 12 h after exposure. Infected leucocytes were identified morphologi...
Wittmann EJ, Baylis M.Changes in the distribution and abundance of insects are likely to be amongst the most important and immediate effects of climate change. We review here the risk that climate change poses to the UK's livestock industry via effects on Culicoides biting midges, the vectors of several arboviruses, including those that cause bluetongue (BT) and African horse sickness (AHS). The major old-world vector of BT and AHS viruses, C. imicola, occurs in southern Europe and will spread further north as global temperatures increase. It is unlikely, however, that in the foreseeable future it will reach and be...
Lu G, Ou J, Ji J, Ren Z, Hu X, Wang C, Li S.Getah virus (GETV) is a mosquito-borne virus that was first determined in Malaysia in 1955, and can infect humans and multiple other mammals. GETV infection in horses has been reported in Japan and India, and causes great economic losses. In China, GETV has been identified in mosquitoes, pigs, foxes, and cattle with a wide geographical distribution, but has not been detected in horses. In August 2018, a sudden onset of fever was observed in racehorse in an equestrian training center in Guangdong Province in southern China. Blood samples were collected from the sick horse, and PCR/RT-PCR analys...
Diab SS, Songer G, Uzal FA.Clostridium difficile is considered one of the most important causes of diarrhea and enterocolitis in horses. Foals and adult horses are equally susceptible to the infection. The highly resistant spore of C. difficile is the infectious unit of transmission, which occurs primarily via the fecal-oral route, with sources of infection including equine feces, contaminated soil, animal hospitals, and feces of other animals. Two major risk factors for the development of C. difficile associated disease (CDAD) in adult horses are hospitalization and antimicrobial treatment, although sporadically, cases...
Ross PF, Rice LG, Osweiler GD, Nelson PE, Richard JL, Wilson TM.During the 1989 corn harvest season, numerous reports of equine leukoencephalomalacia (ELEM) outbreaks and a pulmonary edema (PPE) syndrome in swine from several regions of the United States were received by the National Veterinary Services Laboratories (NVSL), Ames, Iowa. Previous and concurrent research linked Fusarium moniliforme and fumonisin-contaminated feeds to both diseases. Chemical and mycological investigations revealed fumonisin B1 (FB1) concentrations of 20 to 360 ppm in suspect swine feeds and 8 to 117 ppm in suspect equine feeds. Nonproblem feeds contained concentrations below 8...
Koehler K, Stechele M, Hetzel U, Domingo M, Schönian G, Zahner H, Burkhardt E.This report describes a case of cutaneous leishmaniosis in a horse in southern Germany. Diagnosis is based on histopathology, immunohistochemistry and electron microscopy. The protozoan was identified as Leishmania infantum via PCR and restriction fragment length polymorphism. The horse did not show specific Leishmania antibodies. The lesions healed completely within 6 months without any specific treatment. Since neither the infected horse nor its dam had ever left their rural area, autochthonous infection in Germany cannot be excluded. Factors possibly influencing the epidemiological situatio...
Wutz G, Auer H, Nowotny N, Grosse B, Skern T, Kuechler E.Equine rhinoviruses (ERVs) are picornaviruses which cause a mild respiratory infection in horses. The illness resembles the common cold brought about by rhinoviruses in humans; however, the presence of a viraemia during ERV-1 infection, the occurrence of persistent infections and the physical properties are all more reminiscent of foot-and-mouth disease virus (FMDV). cDNA cloning and sequencing of the genomes of ERV-1 and ERV-2 between the poly(C) and poly(A) tracts showed that the serotypes are heterogeneous. Nevertheless, the genomic architecture of both serotypes is most similar to that of ...
Annand EJ, Horsburgh BA, Xu K, Reid PA, Poole B, de Kantzow MC, Brown N, Tweedie A, Michie M, Grewar JD, Jackson AE, Singanallur NB, Plain KM, Kim K....We identified and isolated a novel Hendra virus (HeV) variant not detected by routine testing from a horse in Queensland, Australia, that died from acute illness with signs consistent with HeV infection. Using whole-genome sequencing and phylogenetic analysis, we determined the variant had ≈83% nt identity with prototypic HeV. In silico and in vitro comparisons of the receptor-binding protein with prototypic HeV support that the human monoclonal antibody m102.4 used for postexposure prophylaxis and current equine vaccine will be effective against this variant. An updated quantitative PCR dev...
Reed DS, Glass PJ, Bakken RR, Barth JF, Lind CM, da Silva L, Hart MK, Rayner J, Alterson K, Custer M, Dudek J, Owens G, Kamrud KI, Parker MD, Smith J.Alphavirus replicons were evaluated as potential vaccine candidates for Venezuelan equine encephalitis virus (VEEV), western equine encephalitis virus (WEEV), or eastern equine encephalitis virus (EEEV) when given individually or in combination (V/W/E) to mice or cynomolgus macaques. Individual replicon vaccines or the combination V/W/E replicon vaccine elicited strong neutralizing antibodies in mice to their respective alphavirus. Protection from either subcutaneous or aerosol challenge with VEEV, WEEV, or EEEV was demonstrated out to 12 months after vaccination in mice. Individual replicon v...
Pusterla N, Kass PH, Mapes S, Johnson C, Barnett DC, Vaala W, Gutierrez C, McDaniel R, Whitehead B, Manning J.The prevalence and epidemiology of important viral (equine influenza virus [EIV], equine herpesvirus type 1 [EHV-1] and EHV-4) and bacterial (Streptococcus equi subspecies equi) respiratory pathogens shed by horses presented to equine veterinarians with upper respiratory tract signs and/or acute febrile neurological disease were studied. Veterinarians from throughout the USA were enrolled in a surveillance programme and were asked to collect blood and nasal secretions from equine cases with acute infectious upper respiratory tract disease and/or acute onset of neurological disease. A questionn...
Ergunay K, Gunay F, Erisoz Kasap O, Oter K, Gargari S, Karaoglu T, Tezcan S, Cabalar M, Yildirim Y, Emekdas G, Alten B, Ozkul A.West Nile virus (WNV), a mosquito-borne flavivirus with significant impact on human and animal health, has recently demonstrated an expanded zone of activity globally. The aim of this study is to investigate the frequency and distribution of WNV infections in potential vectors and several mammal and avian species in Turkey, where previous data indicate viral circulation. The study was conducted in 15 provinces across Turkey during 2011-2013. In addition, the entomological study was extended to 4 districts of the Turkish Republic of Northern Cyprus. WNV exposure was determined in humans, horses...
Nally JE, Artiushin S, Timoney JF.Leptospira interrogans is a mammalian pathogen which must adapt to a range of new environmental conditions including temperature change when it infects new hosts. In vitro studies of organisms cultured at 30 degrees C and shifted to 37 degrees C for 5 to 7 days have confirmed that synthesis of several proteins involved in equine infection is regulated in response to temperature change (J. E. Nally, J. F. Timoney, and B. Stevenson, Infect. Immun. 69:400-404, 2001). In order to specifically identify antigenic proteins upregulated at 37 degrees C, groups of three ponies were immunized with organi...
