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.
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...
Baakhtari M, Imaizumi N, Kida T, Yanagita T, Ramah A, Ahmadi P, Takebe N, Iwamoto Y, Korosue K, Tsuzuki N, Yasuda M.High-intensity exercise and competition are associated with depressed immune function. Young horses, which participate in high-intensity exercise and competitions, are at increased risk for the development of infectious disease due to depression of immune function. The effects of branched-chain amino acid (BCAA) supplementation on the immune status of young racing horses were evaluated, determining whether BCAA might help to avoid or reduce immune suppression during exercise and competitions. Twenty horses (10 male and 10 female) were treated with BCAA supplementation; another twenty untreated...
Ocansey BK, Kosmidis C, Agyei M, Dorkenoo AM, Ayanlowo OO, Oladele RO, Darre T, Denning DW.Histoplasmosis is a chronic granulomatous disease caused by the thermally dimorphic fungus Histoplasma capsulatum. The 2 variants Histoplasma capsulatum var. capsulatum (Hcc) and Histoplasma capsulatum var. duboisii (Hcd) causes infection in humans and commonly termed classical or American histoplasmosis and African histoplasmosis, respectively. Histoplasma capsulatum var. farciminosum (Hcf) affects equines. In recent times, there have been heightened sensitization on fungal infections such as histoplasmosis in Africa, aimed at improving awareness among relevant stakeholders, particularly heal...
Yang G, Chen K, Guo W, Hu Z, Qi T, Liu D, Wang Y, Du C, Wang X.Equine piroplasmosis (EP) is a serious problem in the horse industry, and controlling EP is critical for international horse trading. EP is caused by two apicomplexan protozoan parasites, Theileria equi and Babesia caballi. Rapid and accurate methods that are suitable for detecting these parasites in the field are crucial to control the infection and spread of EP. In this study, we developed a card to detect antibodies against T. equi and B. caballi based on two colloidal gold immunochromatographic strips according to the principle of the double-antigen sandwich. The proteins equi merozoite an...
Ravaioli V, Raffini E, Tamburini M, Galletti G, Frasnelli M.Endometritis is a major cause of infertility and subfertility in the mare. Early diagnosis and identification of the pathogens involved in infectious endometritis are crucial to initiate correct treatments in time, in order to optimize fertility and reduce the risk of bacterial resistance development. In this retrospective study (from 2014 to 2018), 394 samples (uterine swabs and lavages) obtained from mares before breeding, regardless of clinical history of endometritis were analyzed. Our bacteriological procedure included the subculturing from the enrichment in Brain Heart Infusion Broth of ...
Peckle M, Pires MS, Dos Santos TM, Roier ECR, da Silva CB, Vilela JAR, Paulino PG, Santos HA, Massard CL.The epidemiological aspects of Babesia caballi infection were evaluated in 516 horse samples from Rio de Janeiro, Brazil. The presence and infestation level of ticks on horses, breed conditions, and animal management were evaluated on each farm through an epidemiological questionnaire. The gene that codes for rhoptry-associated protein-1 (RAP-1) of B. caballi was amplified by nested PCR (nPCR). Among the horses sampled, 17.2% (n = 89/516) presented B. caballi DNA. The characterized samples showed 99-100% similarity with other isolates of B. caballi based on the RAP-1 gene, available in GenBa...
Takai S, Yoda A, Sasaki Y, Kakuda T, Suzuki Y, Oikawa M.Tracheal washing fluid was collected from 170 foals at 28 and 35 d old from February to July in a foaling season on horse-breeding farms with sporadic rhodococcosis in Japan and was investigated by quantitative culture. The history of the 170 foals followed up for the next few months. The proportion of R. equi-positive foals at 28 and 35 d old was significantly increased according to the birth month. Furthermore, the mean number of R. equi in the tracheal washing fluid of each month group increased according to their birth month with the rise in outside temperature. During the follow-up observ...
Falcão MVD, Laroucau K, Vorimore F, Deshayes T, Santana VLA, Silva KPC, do Nascimento SA, de Castro RS, Araújo FR, Mota RA.Glanders is an infectious zoonosis caused by Burkholderia (B.) mallei that mainly affects equids. The objective of this work was to provide additional knowledge on the diversity of the strains circulating in Brazil. Six Burkholderia mallei isolates obtained during necropsies of glanderous horses between 2014 and 2017 in two different states (Pernambuco and Alagoas) were analyzed by polymerase chain reaction-high-resolution melting (PCR-HRM). While four strains (9902 RSC, BM_campo 1, BM_campo 3 and UFAL2) clustered in the L3B2 branch, which already includes the Brazilian 16-2438_BM#8 strain, tw...
Uzal FA, Navarro MA, Asin J, Henderson EE.The clostridial diseases of horses can be divided into three major groups: enteric/enterotoxic, histotoxic, and neurotoxic. The main enteric/enterotoxic diseases include those produced by Clostridium perfringens type C and Clostridioides difficile, both of which are characterized by enterocolitis. The main histotoxic diseases are gas gangrene, Tyzzer disease, and infectious necrotic hepatitis. Gas gangrene is produced by one or more of the following microorganisms: C. perfringens type A, Clostridium septicum, Paeniclostridium sordellii, and Clostridium novyi type A, and it is characterized by ...
Sears KP, Knowles DP, Fry LM.The global importance of the hemoparasite to equine health was recently shown by its resistance to imidocarb dipropionate (ID) and its interference with clearance by ID in some co-infected horses. Genetic characterization of revealed marked genomic reduction compared to , and initial experiments demonstrated reduced clinical severity in spleen-intact horses. Furthermore, in early experiments, splenectomized horses survived infection and progressed to an asymptomatic carrier state, in stark contrast to the high fatality rate of in splenectomized horses. Thus, we hypothesized that is less ...
Shi N, Qiu X, Cao X, Mai Z, Zhu X, Li N, Zhang H, Zhang J, Li Z, Shaya N, Lu H, Jin N.The Getah virus (GETV), a mosquito-borne RNA virus, is widely distributed in Oceania and Asia. GETV is not the only pathogenic to horses, pigs, cattle, foxes and boars, but it can also cause fever in humans. Since its first reported case in Chinese mainland in 2017, the number of GETV-affected provinces has increased to seventeen till now. Therefore, we performed an epidemiologic investigation of GETV in the Xinjiang region, located in northwestern China, during the period of 2017-2020. ELISA was used to analyze 3299 serum samples collected from thoroughbred horse, local horse, sheep, goat, ca...
Cabral LDR, Sato AP, de Sousa RS, Rossa AP, Sanches AWD, Bortoleto CT, Locatelli Dittrich R.The closely related apicomplexa protozoa, Toxoplasma gondii, Neospora spp., and Sarcocystis neurona, have all been associated with neurological and reproductive diseases in horses. However, there is limited data regarding the presence of these three parasites in equine placental tissues and amniotic fluid. The aim of the present report was to investigate the presence of the DNA of T. gondii, Neospora spp. and S. neurona in placentas and amniotic fluid in mares. Anti-T. gondii, anti- S. neurona and anti- Neospora spp. antibody titers were evaluated in 31 mares in the final third of pregnancy by...
Nadal C, Marsot M, Le Metayer G, Boireau P, Guillot J, Bonnet SI.Caused by two blood parasites, and , equine piroplasmosis is a tick-borne disease that poses major health and economic issues for the equine industry. Our objective was to gain insight into the spatio-temporal variations of parasite circulation in France, where the disease is known to be enzootic, but has been the subject of few studies. Seroprevalence was assessed for each parasite thanks to 16,127 equine sera obtained between 1997 and 2003 from all over France and analysed through complement fixation tests. Results indicated that 13.2% (5-27% depending on the region) of horses were seroposi...
Thomson K, Eskola K, Eklund M, Suominen K, Määttä M, Junnila J, Nykäsenoja S, Niinistö K, Grönthal T, Rantala M.Extended-spectrum β-lactamase producing Enterobacterales (ESBL-E) are important causative agents for infections in humans and animals. At the Equine Veterinary Teaching Hospital of the University of Helsinki, the first infections caused by ESBL-E were observed at the end of 2011 leading to enhanced infection surveillance. Contact patients were screened for ESBL-E by culturing infection sites and rectal screening. This study was focused on describing the epidemiology and microbiological characteristics of ESBL-E from equine patients of the EVTH during 2011-2014, and analysing putative risk fac...
Ahedor B, Kothalawala H, Kanagaratnam R, Vimalakumar SC, Otgonsuren D, Tuvshintulga B, Batmagnai E, Silva SSP, Sivakumar T, Yokoyama N.Equine piroplasmosis (EP) is a tick-borne disease caused by Theileria equi and Babesia caballi in equids, including horses, donkeys, zebras, and mules. It is globally endemic with significant economic impact on the equine industry. Infected animals may serve as carriers, and they may be a source of infection for ticks, thereby posing a great challenge for disease management. Sri Lanka is a tropical country, where infections by various tick-borne parasites are common among livestock animals. However, infections by T. equi and B. caballi remain unstudied in Sri Lanka. Therefore, in the present s...
Wollanke B, Gerhards H, Ackermann K.Uveitis is a sight-threatening eye disease in equids known worldwide that leads to considerable pain and suffering. By far the most common type of uveitis in Germany and neighboring countries is classical equine recurrent uveitis (ERU), which is caused by chronic intraocular leptospiral infection and is the main cause of infectious uveitis in horses. Other infectious causes are extremely rare and are usually clinically distinguishable from ERU. ERU can be treated very effectively by vitreous cavity lavage (vitrectomy). For proper indications of this demanding surgery, it is necessary to differ...
Rocafort-Ferrer G, Leblond A, Joulié A, René-Martellet M, Sandoz A, Poux V, Pradier S, Barry S, Vial L, Legrand L.Equine piroplasmosis (EP) is a tick-borne disease caused by Babesia caballi and Theileria equi that is potentially emerging in non-endemic countries. We conducted a descriptive study to investigate EP prevalence and spatial distribution in an endemic region: the Camargue and the Plain of La Crau in France. In spring 2015 and 2016, we carried out sampling at stables (total n = 46) with a history of horses presenting chronic fever or weight loss. Overall, we collected blood from 632 horses, which were also inspected for ticks; these horses had been housed in the target stables for at least 1...
Lotfi Z, Pourmahdi Borujeni M, Ghorbanpoor M, Ghadrdan Mashhadi AR.Brucellosis, as a zoonotic disease, mainly occurs in horses by Brucella abortus, Brucella canis and Brucella suis. The disease in equines is often asymptomatic, but the clinical signs in horses are mostly characterized by bursitis, arthritis and tenosynovitis. This study, thus, aimed to determine the seroprevalence of brucellosis and its associated risk factors in the Arabian horses of Khuzestan province, South-west Iran. To that end, the blood samples randomly collected from 180 Arabian horses were analyzed for the presence of anti-Brucella antibodies by Rose Bengal plate test (RBPT), serum a...
Zhao Y, Zhu Y, Liu B, Mi J, Li N, Zhao W, Wu R, Holyoak GR, Li J, Liu D, Zeng S, Wang Y.Endometritis is a common reproductive disease in equine animals. No investigation about the bacterial characteristics and antimicrobial susceptibility pattern of donkeys with endometritis has thus far been reported. Objective: To determine the common uterine bacterial isolates from donkeys with endometritis and to evaluate their susceptibility to antimicrobials used for the treatment thereof. Methods: Retrospective case-series. Methods: Medical records at an equine clinical diagnostic center were retrospectively reviewed to identify submissions from donkeys with bacterial endometritis between ...
Hosie MJ, Hofmann-Lehmann R.Companion animals, such as cats, dogs, horses and exotic species, play an important role in society; more than 600 million cats and 900 million dogs live closely with humans worldwide [...].
Nielsen SS, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin-Bastuji B, Gonzales Rojas JL, Gortázar C, Herskin M, Michel V, Miranda Chueca MÁ.... () was identified among the most relevant antimicrobial-resistant (AMR) bacteria in the EU for horses in a previous scientific opinion. Thus, it has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9 and Article 8 for listing animal species related to the bacterium. The assessment has been performed following a methodology previously published. The outcome is the med...
Schnittger L, Ganzinelli S, Bhoora R, Omondi D, Nijhof AM, Florin-Christensen M.The order Piroplasmida, including the genera Babesia, Cytauxzoon, and Theileria is often referred to as piroplasmids and comprises of dixenous hemoprotozoans transmitted by ticks to a mammalian or avian host. Although piroplasmid infections are usually asymptomatic in wild animals, in domestic animals, they cause serious or life-threatening consequences resulting in fatalities. Piroplasmids are particularly notorious for the enormous economic loss they cause worldwide in livestock production, the restrictions they pose on horse trade, and the negative health impact they have on dogs and cats. ...
Tirosh-Levy S, Steinman A.Equine encephalosis (EE) is an arthropod-borne, noncontagious, febrile disease of horses. It is caused by EE virus (EEV), an Orbivirus of the Reoviridae family transmitted by Culicoides. Within the EEV serogroup, seven serotypes (EEV-1-7) have been identified to date. This virus was first isolated from a horse in South Africa in 1967 and until 2008 was believed to be restricted to southern Africa. In 2008-2009, isolation of EEV in an outbreak reported from Israel demonstrated the emergence of this pathogen into new niches. Indeed, testing in retrospect sera samples revealed that EEV had alread...
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...
Bergmann F, Trachsel DS, Stoeckle SD, Bernis Sierra J, Lübke S, Groschup MH, Gehlen H, Ziegler U.Following the introduction of the West Nile virus (WNV) into eastern Germany in 2018, increasing infections have been diagnosed in birds, equines, and humans over time, while the spread of WNV into western Germany remained unclear. We screened 437 equine sera from 2018 to 2020, excluding vaccinated horses, collected from convenience sampled patients in the eastern and western parts of Germany, for WNV-specific antibodies (ELISAs followed by virus/specific neutralization tests) and genomes (RT-qPCRs). Clinical presentations, final diagnoses, and demographic data were also recorded. In the easte...
Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Kusano K, Nagata SI.Processed pseudogenes, also known as retrocopy genes, are copies of messenger RNAs that have been reverse transcribed into DNA and inserted into the genome. In this study, we identified 62 processed pseudogene candidates as intron-less genes from whole-genome sequencing (WGS) data of Thoroughbred horses using delly structural variation software. The 62 processed pseudogene candidates were confirmed by PCR amplification of intron-less products. A total of 11 processed pseudogenes were confirmed in the genome of all 23 analysed horses, whereas three processed pseudogenes with structures of ATP11...
Verney M, Gautron M, Lemans C, Rincé A, Hans A, Hébert L.Trypanozoon infections in equids are caused by three parasite species in the Trypanozoon subgenus: Trypanosoma equiperdum, T. brucei and T. evansi. They are respectively responsible for infectious diseases dourine, nagana and surra. Due to the threat that Trypanozoon infection represents for international horse trading, accurate diagnostic tests are crucial. Current tests suffer from poor sensitivity and specificity, due in the first case to the transient presence of parasites in the blood and in the second, to antigenic cross-reactivity among Trypanozoon subspecies. This study was designed to...
Pringle J, Aspán A, Riihimäki M.The value of repeated nasopharyngeal lavage (NPL) to detect silent carriers of Streptococcus equi has not been investigated. Objective: Determine if results of serial testing for S. equi by NPL predicts subsequent true carrier status as determined by both NPL and guttural pouch lavage. Methods: An outbreak of strangles with 100% morbidity in 41 mature Icelandic horses was followed prospectively to investigate development of silent carriers. All were initially positive to S. equi on NPL. The farm was closed to horse movement during the entire study. Methods: Prospective observational study. Tes...
Vaz PK, Horsington J, Hartley CA, Browning GF, Ficorilli NP, Studdert MJ, Gilkerson JR, Devlin JM.Recombination in alphaherpesviruses allows evolution to occur in viruses that have an otherwise stable DNA genome with a low rate of nucleotide substitution. High-throughput sequencing of complete viral genomes has recently allowed natural (field) recombination to be studied in a number of different alphaherpesviruses, however, such studies have not been applied to equine herpesvirus 1 (EHV-1) or equine herpesvirus 4 (EHV-4). These two equine alphaherpesviruses are genetically similar, but differ in their pathogenesis and epidemiology. Both cause economically significant disease in horse popul...
Tanhauser SM, Yowell CA, Cutler TJ, Greiner EC, MacKay RJ, Dame JB.Studies designed to investigate the causative agent of equine protozoal myeloencephalitis and its life cycle have been hampered by the marked similarity of Sarcocystis neurona to other Sarcocystis spp. present in the same definitive host. Random-amplified polymorphic DNA techniques were used to amplify DNA from isolates of S. neurona and Sarcocystis falcatula. DNA sequence analysis of polymerase chain reaction (PCR) products was then used to design PCR primers to amplify specific Sarcocystis spp. DNA products. The ribosomal RNA internal transcribed spacer was also amplified and compared betwee...
Martin G, Plowright R, Chen C, Kault D, Selleck P, Skerratt LF.Hendra virus (HeV) is lethal to humans and horses, and little is known about its epidemiology. Biosecurity restrictions impede advances, particularly on understanding pathways of transmission. Quantifying the environmental survival of HeV can be used for making decisions and to infer transmission pathways. We estimated HeV survival with a Weibull distribution and calculated parameters from data generated in laboratory experiments. HeV survival rates based on air temperatures 24 h after excretion ranged from 2 to 10 % in summer and from 12 to 33 % in winter. Simulated survival across the distri...
Dhondt KP, Horvat B.The Henipavirus genus contains two highly lethal viruses, the Hendra and Nipah viruses and one, recently discovered, apparently nonpathogenic member; Cedar virus. These three, negative-sense single-stranded RNA viruses, are hosted by fruit bats and use EphrinB2 receptors for entry into cells. The Hendra and Nipah viruses are zoonotic pathogens that emerged in the middle of 90s and have caused severe, and often fatal, neurologic and/or respiratory diseases in both humans and different animals; including spillover into equine and porcine species. Development of relevant models is critical for a ...
Geary TG, Sangster NC, Thompson DP.Research in anthelmintic pharmacology faces a grim future. The parent field of veterinary parasitology has seemingly been devalued by governments, universities and the animal industry in general. Primarily due to the success of the macrocyclic lactone anthelmintics in cattle, problems caused by helminth infections are widely perceived to be unimportant. The market for anthelmintics in other host species that are plagued by resistance, such as sheep and horses, is thought to be too small to sustain a discovery program in the animal health pharmaceutical industry. These attitudes are both alarmi...
West Nile virus (WNV) is a member of the Japanese encephalitis serocomplex, which was first described in 1937 as neurotropic virus in Uganda in 1937. Subsequently, WNV was identified in the rest of the old-world and from 1999 in North America. Birds are the primary hosts, and WNV is maintained in a bird-mosquito-bird cycle, with pigs as amplifying hosts and humans and horses as incidental hosts. WNV transmission is warranted by mosquitoes, usually of the spp., with a tendency to spill over when mosquitoes' populations build up. Other types of transmissions have been described in endemic areas...
Dei-Cas E, Brun-Pascaud M, Bille-Hansen V, Allaert A, Aliouat EM.As in vitro culture systems allowing to isolate Pneumocystis samples from patients or other mammal hosts are still not available, animal models have critical importance in Pneumocystis research. The parasite was reported in numerous mammals but P. carinii pneumonia (PCP) experimental models were essentially developed by using rats, mice, rabbits and ferrets. The rat treated with corticosteroids for 9-12 weeks is a useful PCP model. Like laboratory rats, conventional mice develop PCP after prolonged corticosteroid administration. The ferret (Mustela putorius furo) also develop PCP under cortico...
Young R, Taylor JE, Kurioka A, Becker M, Louis EJ, Rudenko G.African trypanosomes (including Trypanosoma brucei) are unicellular parasites which multiply in the mammalian bloodstream. T. brucei has about twenty telomeric bloodstream form Variant Surface Glycoprotein (VSG) expression sites (BESs), of which one is expressed at a time in a mutually exclusive fashion. BESs are polycistronic transcription units, containing a variety of families of expression site associated genes (ESAGs) in addition to the telomeric VSG. These polymorphic ESAG families are thought to play a role in parasite-host adaptation, and it has been proposed that ESAG diversity might ...
Balasuriya UB, Lee PY, Tiwari A, Skillman A, Nam B, Chambers TM, Tsai YL, Ma LJ, Yang PC, Chang HF, Wang HT.Equine influenza (EI) is an acute, highly contagious viral respiratory disease of equids. Currently, equine influenza virus (EIV) subtype H3N8 continues to be the most important respiratory pathogen of horses in many countries around the world. The need to achieve a rapid diagnosis and to implement effective quarantine and movement restrictions is critical in controlling the spread of EIV. In this study, a novel, inexpensive and user-friendly assay based on an insulated isothermal RT-PCR (iiRT-PCR) method on the POCKIT™, a field-deployable device, was described and validated for point-of-nee...
Paillot R, Darby AC, Robinson C, Wright NL, Steward KF, Anderson E, Webb K, Holden MT, Efstratiou A, Broughton K, Jolley KA, Priestnall SL....The acquisition of superantigen-encoding genes by Streptococcus pyogenes has been associated with increased morbidity and mortality in humans, and the gain of four superantigens by Streptococcus equi is linked to the evolution of this host-restricted pathogen from an ancestral strain of the opportunistic pathogen Streptococcus equi subsp. zooepidemicus. A recent study determined that the culture supernatants of several S. equi subsp. zooepidemicus strains possessed mitogenic activity but lacked known superantigen-encoding genes. Here, we report the identification and activities of three novel ...
Wild TF.Paramyxoviruses have been implicated in both animal and human infections. Some viruses, such as Morbilliviruses are responsible for large-scale epidemics. However, there are limited observations of these viruses crossing the host species barrier in nature. In 1994, in Australia a fatal infection in horses and humans was identified to be caused by a new Paramyxovirus, Hendra virus (HeV), and in 1998 in Malaysia, a closely related virus, Nipah virus (NiV) was responsible for fatal infections in pigs and humans. These two viruses were sufficiently different from previously described Paramyxovirus...
Arthropodborne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes and ticks. Symptomatic infections most often manifest as a systemic febrile illness and, less commonly, as neuroinvasive disease (e.g., meningitis, encephalitis, or acute flaccid paralysis). West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease in the United States. However, several other arboviruses also cause seasonal outbreaks and sporadic cases. In 2011, CDC received reports of 871 cases of nationally notifiable arboviral diseases (excluding deng...
Adams AP, Navarro-Lopez R, Ramirez-Aguilar FJ, Lopez-Gonzalez I, Leal G, Flores-Mayorga JM, Travassos da Rosa AP, Saxton-Shaw KD, Singh AJ....Venezuelan equine encephalitis virus (VEEV) has been the causative agent for sporadic epidemics and equine epizootics throughout the Americas since the 1930s. In 1969, an outbreak of Venezuelan equine encephalitis (VEE) spread rapidly from Guatemala and through the Gulf Coast region of Mexico, reaching Texas in 1971. Since this outbreak, there have been very few studies to determine the northward extent of endemic VEEV in this region. This study reports the findings of serologic surveillance in the Gulf Coast region of Mexico from 2003-2010. Phylogenetic analysis was also performed on viral is...
Whatmore AM, King SJ, Doherty NC, Sturgeon D, Chanter N, Dowson CG.Although often considered a strict human pathogen, Streptococcus pneumoniae has been reported to infect and cause pneumonia in horses, although the pathology appears restricted compared to that of human infections. Here we report on the molecular characterization of a group of S. pneumoniae isolates obtained from horses in England and Ireland. Despite being obtained from geographically distinct locations, the isolates were found to represent a tight clonal group, virtually identical to each other but genetically distinguishable from more than 120 divergent isolates of human S. pneumoniae. A co...
Middleton DJ, Weingartl HM.Hendra virus (HeV) and Nipah virus (NiV) form a separate genus Henipavirus within the family Paramyxoviridae, and are classified as biosafety level 4 pathogens due to their high case fatality rate following human infection and because of the lack of effective vaccines or therapy. Both viruses emerged from their natural reservoir during the last decade of the twentieth century, causing severe disease in humans, horses and swine, and infecting a number of other mammalian species. The current review summarizes our up to date understanding of pathology and pathogenesis in the natural reservoir spe...
Li W, Plante JA, Lin C, Basu H, Plung JS, Fan X, Boeckers JM, Oros J, Buck TK, Anekal PV, Hanson WA, Varnum H, Wells A, Mann CJ, Tjang LV, Yang P....Western equine encephalitis virus (WEEV) is an arthropod-borne virus (arbovirus) that frequently caused major outbreaks of encephalitis in humans and horses in the early twentieth century, but the frequency of outbreaks has since decreased markedly, and strains of this alphavirus isolated in the past two decades are less virulent in mammals than strains isolated in the 1930s and 1940s. The basis for this phenotypic change in WEEV strains and coincident decrease in epizootic activity (known as viral submergence) is unclear, as is the possibility of re-emergence of highly virulent strains. Here...
García-Bocanegra I, Rivero A, Caballero-Gómez J, López-López P, Cano-Terriza D, Frías M, Jiménez-Ruiz S, Risalde MA, Gómez-Villamandos JC....Hepatitis E (HE) is an important emerging disease in European countries. To analyse the role of equids as potential reservoirs for HE virus (HEV), we determined the prevalence of HEV infection in 861 equines from 464 herds in Spain. HEV RNA in serum was detected in 0.4% (3/692) of horses, 1.2% (1/86) of donkeys and 3.6% (3/83) of mules. Phylogenetic analysis identified the zoonotic genotype 3 as being closely related to viral human and swine strains. In this first report on HEV in equids in Europe, we confirm the susceptibility of horses, donkeys and mules to HEV infection. The low prevalence ...
Wagner B, Goodman LB, Babasyan S, Freer H, Torsteinsdóttir S, Svansson V, Björnsdóttir S, Perkins GA.Equine herpesvirus type 1 (EHV-1) continues to cause severe outbreaks of abortions or myeloencephalopathy in horses despite widely used vaccination. The aim of this work was to determine the effects of frequent vaccination with an inactivated EHV vaccine on immune development in horses. Fifteen EHV-1 naïve mares were vaccinated a total of 5 times over a period of 8 months with intervals of 20, 60, 90 and 60 days between vaccine administrations. Total antibody and antibody isotype responses were evaluated with a new sensitive EHV-1 Multiplex assay to glycoprotein C (gC) and gD for up to 14 mon...
PLUMMER G.A VIRUS was isolated in monkey kidney tissue cultures from the fæces of 13 of 290 horses held in the stables of the Wellcome Research Laboratories. One of these strains was selected for investigation. Rabbit hyperimmune serum prepared against it and possessing a neutralizing titre of 1/4,000 neutralized all 12 remaining isolates to the same titre.
Theelen MJ, Wilson WD, Edman JM, Magdesian KG, Kass PH.Sepsis is an important cause of death in foals. Knowledge of which pathogens are likely to be involved is important for selection of antimicrobial drugs for initial treatment. Objective: To identify temporal trends in prevalence of bacteria isolated from foals with sepsis between 1979 and 2010. Methods: Retrospective review of medical records. Methods: All foals ≤30 days of age presented to the Veterinary Medical Teaching Hospital (VMTH) at the University of California, Davis between 1979 and 2010, with a diagnosis of sepsis confirmed by culture of bacteria from blood or internal organs (ant...
Friedhoff KT, Soulé C.A review of the distribution of Babesia equi and Babesia caballi, the
transmission of these protozoa by ticks and the immune response of infected
horses, in addition to a brief survey of diagnostic. tests and chemotherapy.
Fritsche AK, Borchers K.A single nucleotide polymorphism within EHV-1 gene ORF 30, which encodes for the viral DNA polymerase, allows the differentiation of the neuropathogenic (G2254) from non-neuropathogenic genotype (A2254). The aim of our study was to investigate the distribution of the neuropathogenic and non-neuropathogenic genotype of EHV-1 isolates associated with abortions in Germany. To determine the nucleotide sequence at the polymorphic site the amplification product of ORF 30 gene specific nested PCR was digested with restriction enzyme SalI and sequenced. Thirty-two EHV-1 isolates from six abortion outb...
Gomez HH, Georgi JR.A programme of selective anthelmintic therapy was used in a herd of 31 horses. Faecal egg counts were done during the months of September, November, January, March, May and the following September. Horses with greater than or equal to 100 eggs per gram (epg) were treated with ivermectin, and those with less than 100 epg were not treated. The criteria for adequate internal parasite control in the herd was a median herd faecal egg count of less than or equal to 100 epg. Effectiveness of selective therapy was assessed by faecal egg count after nine months of treatment and was determined to be ade...
Edington N, Welch HM, Griffiths L.Equid herpesviruses 1 or 4 (EHV-1 or -4) were isolated by cocultivation from 60% of 40 horses examined at slaughter. The lymph nodes draining the respiratory tract were the most common source of virus. EHV-1 or EHV-4 was never isolated from the trigeminal ganglia (SLG). The polymerase chain reaction (PCR) detected virus in 87.5% of bronchial lymph nodes and a similar level in the trigeminal ganglia that were examined. By both assays approximately one third of the positive animals harboured both viruses. Equid herpesvirus 2 (EHV-2) was isolated from all but one of the horses and from > 75% o...
Matsuo K, Kamai R, Uetsu H, Goto H, Takashima Y, Nagamune K.The presence of antibodies to Toxoplasma gondii in livestock and poultry was investigated by latex agglutination tests; samples that agglutinated at dilutions of 1:64 or higher were regarded as positive. Sera were collected from fattening beef cattle (102 Japanese black, 105 crossbreeds and 114 castrated Holstein), culled dairy cattle (101 Holstein), 100 horses, 115 fattening pigs and 235 chickens (163 free-range and 72 broilers) at abattoirs in Gifu Prefecture, Japan, from August 2012 to August 2013. Antibodies to T. gondii were found in 7.3% (31/422) in cattle, 5.2% (8/155) in pigs, but not ...
Walther B, Klein KS, Barton AK, Semmler T, Huber C, Merle R, Tedin K, Mitrach F, Lübke-Becker A, Gehlen H.Continuing introduction of multi-drug resistant, zoonotic pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) in horse clinics challenges the biosafety of employees and animal patients. This study was aimed to determine the occurrence of mobile genetic elements facilitating survival in the early stages of invasive infection in different host species, including humans and horses, in MRSA carried by equine patients admitted to a large horse clinic. A total of 341 equine patients were investigated for carriage of MRSA by hygiene screening directly at hospital admission. MRSA were...
