Epidemiology in horses involves the study of the distribution and determinants of health-related states and events in equine populations. It encompasses the investigation of patterns, causes, and effects of diseases and health conditions within horse populations. This field of study aims to identify risk factors for disease and targets for preventive healthcare. Key components of equine epidemiology include disease surveillance, outbreak investigation, and the study of disease dynamics within herds or regions. Research in this area often focuses on infectious diseases, zoonotic diseases, and the impact of environmental factors on equine health. This page compiles peer-reviewed research studies and scholarly articles that explore various aspects of epidemiology in horses, including disease prevalence, transmission pathways, and strategies for disease prevention and control.
Kwak ML, Echigo H, Hoketsu T, Taya Y, Numata H, Shiraki Y, Kelava S, Markowsky G, McInnes D, Hayashi N, Nonaka N, Kawai M, Nakao R.The control of ticks is challenging owing to their ubiquity, complex ecologies, and difficulties relating to costs and non-target impacts of chemical control programs. Nature-based solutions centre around co-opting natural processes and biodiversity to address socio-environmental problems; and in some cases, rewilded species can provide nature-based solutions. In northern Japan, the winter ecology of ticks is poorly studied, though some species are believed to overwinter under the snow. Winter grazing activity of rewilded horses may disturb overwintering ticks, exposing them to sub-zero temper...
Barber C, McGlennon A, Whitlock F, Grewar J, Spalding S, Newton R, Dewé T.Charlotte Barber, Abigail McGlennon, Fleur Whitlock, John Grewar, Sophie Spalding, Richard Newton and Tamsin Dewé introduce a new government-funded initiative to strengthen the surveillance of antimicrobial resistance in the equine sector.
Costa VMD, de Aguiar Filho RN, Braz GF, Paz CFR, Drumond BP, Teixeira BM, Kroon EG.Equine infectious anemia (EIA) is a chronic disease caused by the equine infectious anemia virus (EIAV), a member of the Retroviridae family and the Lentivirus genus. Most infected animals are asymptomatic carriers, which makes clinical diagnosis challenging. This study aimed to conduct a clinical and laboratory evaluation of EIA in equids used for equestrian tourism in Jericoacoara National Park, Ceará, Brazil. A total of 112 equids (104 horses and 8 mules) underwent clinical, hematological, biochemical, serological, and molecular assessments. The EIAV seropositivity rates were 11.6% by AGID...
Björnsdóttir S, Sigurðardóttir ÓG, Oddsdóttir C, Reynisdóttir I, Hanche-Olsen S, Gröndahl G.Acquired equine polyneuropathy is a neuromuscular syndrome characterized by digital extensor dysfunction, primarily affecting the pelvic limbs, with consistent, repeated knuckling. Despite being recognized as an emerging disease in Scandinavia since 1995, the aetiology remains unknown, and cases have been limited to Norway, Sweden, and Finland. Methods: On a combined breeding and training farm in Iceland, 30 out of 145 horses (21%) presented with acute pelvic weakness, pelvic limb digital extensor dysfunction, knuckling and/or recumbency, from May to August 2019. The affected horses, aged 2-9...
Simó-Martínez MS, Marco-Fuertes A, Galán-Relaño Á, Astorga Márquez RJ, Marin C, Valero Díaz A, Vega S. are zoonotic pathogens, and rising antimicrobial resistance (AMR) amplifies their public health impact. Asymptomatic horses can act as reservoirs, contributing to environmental contamination and interspecies transmission. This study aimed to estimate the prevalence of and characterize AMR patterns in healthy horses from eastern Spain. Faecal samples from 95 asymptomatic horses were collected once daily over five consecutive days (475 samples in total) and processed under for detection. Epidemiological information was obtained through owner questionnaires, and associations with shedding we...
McDonald S, Verheyen KLP, Chang YM, Allen SE.Race-related injuries in horse racing, especially those requiring extended recovery, are a welfare concern and threaten the sport's social licence. Previous studies predominantly report on fatalities; however, serious non-fatal musculoskeletal injuries often end horses' racing careers or have a high recurrence risk. No recent studies have described or quantified long-term injuries (LTIs) in racing Thoroughbreds, which is essential to inform targeted risk prevention strategies. Objective: To describe the types, frequencies and incidences of LTIs in British jump racing. Methods: Retrospective co...
Gunsmaa G, Gurbazar U, Badarch TU, Ichikawa M.The aim of this study was to assess the effectiveness of safety regulations governing traditional Mongolian horse racing on the frequency and severity of injuries among child jockeys. Regulations introduced in 2019 mandate the wearing of helmets and protective clothing, prohibit the participation of jockeys aged < 7 years, and ban horse racing during the cold season (November-April). National injury surveillance data were used to compare the profile of injuries that occurred among children aged < 15 years in the 4-year periods before and after the introduction of the regulations (2015-2018 ...
White J, Thompson K, van den Berg D, O'Neill G, Mendez DH, Talwar J, Degeling C, Forsythe R, Durrheim DN.With more than 60% of emerging infectious diseases being zoonotic, we apply a One Health lens that connects human, animal, and environmental dimensions of the response to a Hendra virus (HeV) event. One Health promotes collaboration among health professionals, veterinarians, environmental scientists, and policymakers to strengthen health infrastructure and improve responses to complex health threats. HeV is an uncommon high-consequence and potentially fatal zoonotic disease endemic to parts of Australia. Previous research has largely focused on the uptake of preparedness measures by veterinari...
Ken-Dror G, Chua V, Sharma P.To determine the frequency of traumatic injuries in polo players in England. Methods: The survey included data on body location and reason for injury derived from accident reports using a retrospective cohort design from 26 participating English polo clubs between the years 2018 and 2024. Results: The study population included injuries in 236 polo players. The most common injury site was the limb (arm, hand, leg, wrist, shoulder) 47.9% (95% CI: 41.4-54.5), and face or head 38.6% (95% CI: 32.3-45.1), of which 12.1% (95% CI: 6.2-20.6) affected the eyes. The most common reason to require hospital...
West Nile Virus (WNV) is a mosquito-borne zoonosis with recurrent equine and human cases in Romania. Horses, although dead-end hosts, act as sentinels for local viral circulation. Farm-level risk conditions remain under-characterized. This pilot, exploratory cross-sectional study assessed 42 equine facilities in western Romania (2024). A standardized 10-item checklist was applied and a Composite Environmental Risk Score (CERS) (0-10, unweighted) was computed per facility. Spatial analysis in QGIS included distances to nearby water bodies. No serological or entomological data were collected; th...
Hananeh W, Al Rukibat R, Hammad H, Mukbel R.Leishmaniosis is an endemic parasitic infection in Jordan and the Middle East. Despite the endemicity of leishmaniosis in Jordan and frequently reported humancases, no singleclinical case has been documented in animals throughout the country. This report documents the first two animal Leishmania cases in two different animal species with a current literature review. Cutaneous leishmaniosis was diagnosed in an adult horse that presented with multiple variably sized skin nodules, some of which ulcerated. Visceral leishmaniosis was diagnosed in a stray dog. Cytological, histopathological, and mol...
Piketh G, Viljoen A, Eberhardt C.Equine encephalosis (EE) is caused by an Orbivirus from the family Sedoreoviridae and is thus similar to African horse sickness (AHS) and Bluetongue viruses (BTV). These viruses are transmitted by Culicoides midges. Equine encephalosis can infect horses, donkeys and zebras sub-clinically while only horses develop clinical disease. The vector's distribution is climate-dependent with evidence for circulation in Southern Africa, the Middle East and India. Global warming could facilitate the expansion of this distribution and consequently the potential spread into Europe should not be overlooked. ...
Linnegar B, Hoegh A, McCallum H, Peel AJ.Anthropogenic climatic and landscape change can drive behavioural shifts in wildlife and thus lead to increased risk of pathogen exposure for humans and domestic animals. While spillover research often focuses on the reservoir hosts or ongoing transmission in humans, livestock and companion animals can play important roles as bridging and amplifying hosts, facilitating the emergence of highly pathogenic diseases. Objective: To investigate the distribution and density of domestic horses in the context of their role as bridge hosts for Hendra virus and build models to study zoonotic emergence. M...
Haywood LMB, Clark A, Hause B, Sheahan B.Many cases of equine enterocolitis are suspected to be infectious in nature, but no pathogen is identified in many cases. Objective: Perform next-generation sequencing on faeces collected from cases of equine enterocolitis for the presence of novel viruses and determine if an identified novel virus is associated with cases of equine enterocolitis. Methods: Retrospective cohort study. Methods: Next generation sequencing was performed targeting viral genomes from n = 13 pooled faecal samples (n = 5 horses/pool) with enterocolitis. Subsequent qPCR was performed targeting the highly conser...
Silva-Ramos CR, Niño Rodríguez JA, Gil-Mora J, Betancourt-Ruiz P, Martínez-Díaz HC, Forero-Becerra E, Matiz-González JM, Bolaños E, Olaya-M LA....Babesia species are tick-borne protozoan parasites which affect several animal species. Babesia spp. infections are significantly important for veterinary medicine, affecting a wide range of domestic animal species such as dogs, cattle, and horses. In Colombia, studies of Babesia spp. infections in domestic animals are scarce. Thus, the aim of the present study was to explore the circulation of these parasites among domestic canines, bovines and equines from the department of Cauca. Methods: Between August and November, 2017, active domestic animal sampling of cattle was performed in eight rur...
This study presents the first investigation of West Nile virus (WNV) seroprevalence among farmed horses in Kazakhstan. In 2024, a total of 368 serum samples were collected from horses across 106 settlements in 10 regions of the Republic of Kazakhstan. Using an enzyme-linked immunosorbent assay (ELISA), antibodies to WNV were detected in 32 horses (8.7%; 95% CI: 6.2-12.0%) from six regions. Among the seropositive animals, 26 (81.25%) were females and 6 (18.75%) were males, ranging in age from 1 to 19 years. No statistically significant association between sex and the presence of antibodies to W...
Wang L, Zheng R, Li Z, Zhang L.Recent increases in cases of western equine encephalitis (WEE) in South America have raised significant concerns about the virus's potential to cause an endemic disease due to its adaptation to mosquito vectors. Currently, there are no effective vaccines or treatments for WEEV, despite ongoing research into various biochemical products in animal models. The virus presents different pathological effects depending on the host. In humans, WEEV infection leads to central nervous system damage, resulting in encephalitis and severe neurological sequelae, which underscores the need for further resear...
Malek IA, Baharudin F, Peng TL, Sabri J.Equine strongyles are harmful gastrointestinal parasites affecting horses' health and productivity. In tropical regions, environmental conditions, including temperature and soil type, significantly influence the development and survivability of strongyle larvae. This study aims to assess the development and survival of third-stage larvae (L3) of strongyles under different temperatures and soil types commonly found in Malaysia. Faecal samples from five adult horses aged between 22-24 years that were kept under a semi-intensive management system and had no history of recent anthelmintic treatmen...
: isolates from humans and horses of the equine-associated clonal complexes (CCs) CC1 and CC1660 were comparatively investigated for their genomic relationships. : A total of 91 isolates (64 human, 27 equine) were subjected to whole-genome sequencing (WGS), sequence analysis, and antimicrobial susceptibility testing. : WGS confirmed 75 CC1 and 16 CC1660 isolates, comprising nine sequence types (STs) in CC1 and four STs in CC1660. Ten types were present in CC1 and five in CC1660. In the gene of three CC1 isolates, a 285 bp deletion was detected, and a nucleotide deletion causing a premature...
Zhang Y, Zheng J, Zhang H, Lin Y, Wang Y, Ma Z, Wei J, Zhou B, Zhong D.Getah virus (GETV), Japanese encephalitis virus (JEV), West Nile virus (WNV), and African horse sickness virus (AHSV) are mosquito-borne viruses threatening the health of racehorses. However, the systematic surveillance of these viruses among Shanghai racehorses remains lacking. Therefore, molecular and serological surveillance was conducted for these viruses in racehorses and mosquitoes at horse farms in Shanghai, China, during 2022 to assess their prevalence. Among 11,140 mosquitoes collected from seven farms across four districts, and were identified as the dominant species. RT-qPCR detec...
Narouei M, Rahimi H, Kafshdouzan K.Infections caused by and , as zoonotic diseases, pose a serious threat to the health of humans and animals. To date, there is limited information regarding these diseases in horses. This study aimed to evaluate the prevalence of and in the serum of racehorses in Iran (Golestan province). 350 blood samples were collected from racehorses in four regions of Golestan province, and demographic data (sex, age, and sampling location) were recorded. The collected serum samples were examined by PCR to identify the genomes of and . The results showed that 3.4 % (P < 0.05, 95 % CI: 1.97 % - 5.9 %) of...
Mota RA, Silito IS, Martins MP, Oliveira PRF, Melo RPB, Vieira da Silva V, Jorge FR, Martins TF, Labruna MB.Tick-borne diseases are among the most widespread vector-borne infections, including zoonoses caused by bacterial and protozoal microorganisms. This study consisted of a serosurvey for Rickettsia spp. in 270 horses from 11 farms in the coastal region of Pernambuco, Brazil. Through the indirect immunofluorescence assay (IFA) based on antigens of five Rickettsia species, 164 (60.7%) horses were seroreactive to Rickettsia spp., with seroreactivity among farms ranging from 10 to 100%. Through molecular analysis, all 270 horse blood DNA samples tested negative by PCR assays targeting Anaplasmatacea...
Raftery AG, Gummery L, Garcia K, Mohite D, Capewell P, Sutton DGM.Equine trypanosomiasis is a neglected protozoal disease. Objective: To perform a systematic search of literature to explore: (1) In equines what is the global geographical distribution and prevalence of trypanosomiasis? In low and middle-income countries (LMICs) is trypanosomiasis more prevalent than in higher-income countries (HICs)? (2) Is trypanosomiasis infection a significant contributor to global morbidity and mortality? Methods: Systematic review and meta-analyses. Methods: Studies were identified that described naturally occurring equine trypanosomiasis worldwide following 'Preferred R...
Zanilabdin M, Ilgekbayeva G, Otarbayev B, Nissanova R, Mussayeva G, Takai S, Suzuki Y, Kakuda T, Kurman S, Kassymov Y, Valiyeva B. is a facultative intracellular pathogen causing bronchopneumonia in foals; data from Central Asia are limited. We conducted a cross-sectional serological and molecular survey in horses from three regions of Kazakhstan (Kyzylorda, Almaty, Akmola). Unassigned: Sera from 312 animals (272 adults, 40 foals) on 20 farms were tested by indirect ELISA. Selected clinical samples underwent culture, PCR, and 16S rRNA sequencing. Unassigned: Overall seroprevalence was 8.3% (26/312; 95% CI 5.8-11.9). Positivity among foals was 25.0% (10/40; 95% CI 14.2-40.2) versus 5.9% (16/272; 95% CI 3.7-9.3) in adults,...
Abbas G, Nielsen MK, E-Hage C, Ghafar A, Beveridge I, Bauquier J, Beasley A, Wilkes EJA, Carrigan P, Cudmore L, Jacobson C, Hughes KJ, Jabbar A.Over the past 25 years, significant progress has been made in understanding and managing equine gastrointestinal parasites in the Asia-Pacific region, particularly in Australia and New Zealand. This review synthesises current knowledge of the epidemiology, diagnostic methods, anthelmintic resistance (AR), and control strategies for major equine intestinal parasites, including cyathostomins, Parascaris spp., Anoplocephala perfoliata, and Strongyloides westeri. Recent studies highlight substantial regional variation in parasite prevalence, egg shedding and cyathostomin population composition, sh...
Asteraye GB, Jobling R, Jemberu WT, Pinchbeck G, Knight-Jones TJD, Critchlow R, Rushton J, Chaters GL.Working donkeys play a critical role in transportation, agriculture and household resilience in low- and middle-income countries. Other animals that are kept for production purposes, such as cattle, are often grouped into broad production system classes, such as dairy or pastoral, for comparison between and better understanding of the needs and outputs of animals within specific sectors. Despite the importance of working donkeys for sustaining livelihoods there are no systematic classifications of these populations. The aim of this study was to classify and characterise donkey systems in Ethio...
Al-Ebshahy E, Badr Y, El-Ansary RE, Alajmi R, El-Ashram S, Rady A, Elgendy E.The present study investigated the molecular detection and genetic characteristics of equine herpesvirus 1 (EHV-1) and EHV-4 circulating within Egyptian horse populations during 2019-2022. A total of 79 animals were sampled (54 nasal swabs and 25 aborted fetal tissues). PCR assays revealed that 24 (30.3%) and 7 (8.8%) samples were positive for EHV-1 and EHV-4, respectively. Additionally, 5 (6.3%) samples were concurrently infected with both viruses. Four EHV-1 and three EHV-4 isolates were genetically characterized based on partial sequencing of gB gene. The four EHV-1 strains displayed 100% n...
Gillen A, Hassel D, Gonzalez S, Savage V, Bauck A, Freeman D, Archer DC.Obstruction by strangulating lipoma (SLO) is one of the most common causes of small intestinal strangulation in horses and is fatal without surgery. Current knowledge of risk factors for SLO is limited to horse signalment features. To date, other risk factors have not been investigated. Objective: To investigate horse- and management-level risk factors for SLO using a population of healthy horses as controls. Methods: Matched, case-control study. Methods: A prospective, international multicentre study was conducted in the UK and USA between January 2022 and May 2024. Cases were horses with SLO...
de la Fuente J, Massung RF, Wong SJ, Chu FK, Lutz H, Meli M, von Loewenich FD, Grzeszczuk A, Torina A, Caracappa S, Mangold AJ, Naranjo V, Stuen S....The causative agent of human granulocytic ehrlichiosis was recently reclassified as Anaplasma phagocytophilum, unifying previously described bacteria that cause disease in humans, horses, dogs, and ruminants. For the characterization of genetic heterogeneity in this species, the homologue of Anaplasma marginale major surface protein 4 gene (msp4) was identified, and the coding region was PCR amplified and sequenced from a variety of sources, including 50 samples from the United States, Germany, Poland, Norway, Italy, and Switzerland and 4 samples of A. phagocytophilum-like organisms obtained f...
Schmiedel J, Falgenhauer L, Domann E, Bauerfeind R, Prenger-Berninghoff E, Imirzalioglu C, Chakraborty T.Multiresistant Gram-negative bacteria producing extended-spectrum β-lactamases (ESBLs) are an emerging problem in human and veterinary medicine. This study focused on comparative molecular characterization of β-lactamase and ESBL-producing Enterobacteriaceae isolates from central Hesse in Germany. Isolates originated from humans, companion animals (dogs and cats) and horses. Results: In this study 153 (83.6%) of the human isolates (n = 183) and 163 (91.6%) of the animal isolates (n = 178) were confirmed as ESBL producers by PCR and subsequent sequencing of the PCR amplicons. Predomin...
Scoles GA, Ueti MW.Equine piroplasmosis is a disease of Equidae, including horses, donkeys, mules, and zebras, caused by either of two protozoan parasites, Theileria equi or Babesia caballi. These parasites are biologically transmitted between hosts via tick vectors, and although they have inherent differences they are categorized together because they cause similar pathology and have similar morphologies, life cycles, and vector relationships. To complete their life cycle, these parasites must undergo a complex series of developmental events, including sexual-stage development in their tick vectors. Consequentl...
Frost MJ, Zhang J, Edmonds JH, Prow NA, Gu X, Davis R, Hornitzky C, Arzey KE, Finlaison D, Hick P, Read A, Hobson-Peters J, May FJ, Doggett SL....To determine the cause of an unprecedented outbreak of encephalitis among horses in New South Wales, Australia, in 2011, we performed genomic sequencing of viruses isolated from affected horses and mosquitoes. Results showed that most of the cases were caused by a variant West Nile virus (WNV) strain, WNV(NSW2011), that is most closely related to WNV Kunjin (WNV(KUN)), the indigenous WNV strain in Australia. Studies in mouse models for WNV pathogenesis showed that WNV(NSW2011) is substantially more neuroinvasive than the prototype WNV(KUN) strain. In WNV(NSW2011), this apparent increase in vir...
Johnston GM, Eastment JK, Wood J, Taylor PM.To document the equine perioperative mortality rate and to highlight any factor associated with an increased risk of death up to 7 days after anaesthesia. Methods: A prospective observational epidemiological multicentre study. Methods: Data were recorded from all equidae undergoing general anaesthesia in 62 clinics. Power calculations indicated that 45 000 cases were required to detect the significance of important variables. Details of each horse, operation, anaesthetic agents and clinic personnel were recorded. Outcome at 7 days was recorded as: alive, put to sleep (PTS) or dead. Data were a...
Criado-Fornelio A, Martinez-Marcos A, Buling-Saraña A, Barba-Carretero JC.Molecular epizootiology of piroplasmids (Babesia spp., Theileria spp.) and Hepatozoon canis was studied in mammals from southern Europe (mainly from Spain, but also from Portugal and France). Partial amplification and sequencing of the 18s rRNA gene was used for molecular diagnosis. In some particular cases (B. ovis and B. bovis) the complete 18s rRNA gene was sequenced. Blood samples were taken from domestic animals showing clinical symptoms: 10 dogs, 10 horses, 10 cows, 9 sheep and 1 goat. In addition, DNA samples were isolated from blood of 12 healthy dogs and from spleen of 10 wild red fox...
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. ...
Chandriani S, Skewes-Cox P, Zhong W, Ganem DE, Divers TJ, Van Blaricum AJ, Tennant BC, Kistler AL.Theiler's disease is an acute hepatitis in horses that is associated with the administration of equine blood products; its etiologic agent has remained unknown for nearly a century. Here, we used massively parallel sequencing to explore samples from a recent Theiler's disease outbreak. Metatranscriptomic analysis of the short sequence reads identified a 10.5-kb sequence from a previously undescribed virus of the Flaviviridae family, which we designate "Theiler's disease-associated virus" (TDAV). Phylogenetic analysis clusters TDAV with GB viruses of the recently proposed Pegivirus genus, altho...
Montelaro RC, Parekh B, Orrego A, Issel CJ.The recurrent nature of equine infectious anemia has been attributed to relatively rapid antigenic variations in equine infectious anemia virus (EIAV) during persistent infection under selective immune pressures. This model was tested by serological and biochemical analysis of virus isolates recovered from separate febrile episodes in two experimentally infected ponies. Neutralization assays employing immune sera from the experimentally infected ponies demonstrated that distinct antigenic strains of virus predominate during sequential febrile episodes in a single pony. Analysis of the test str...
Mehlhorn H, Schein E.The horse-parasitizing species Babesia equi Laveran, 1901 was redescribed as Theileria equi Mehlhorn, Schein 1998 and, thus, transferred from one valid genus to another. This transfer was needed since it turned out that this horse parasite showed the relevant characteristics of theilerians with regard to biological data, morphological features, biochemical properties, and molecular biological relationships.
Azlaf R, Dakkak A.The objectives of this epidemiological study on cystic echinococcosis (CE) in Morocco (2001-2004) were to update the prevalence of CE in different animal species living in the most important areas of the country and to collect protoscoleces and germinal layers for genetic research purposes. The post mortem inspection concerned 2948 sheep, 2337 goats, 618 cattle, 482 camels and 455 equines (325 horses, 60 mules and 70 donkeys) in five different regions: the Rif (Mediterranean coast and high mountains of the Rif), the Loukkos (Atlantic northwest plain), the center (Rabat and Casablanca regions),...
Rivas F, Diaz LA, Cardenas VM, Daza E, Bruzon L, Alcala A, De la Hoz O, Caceres FM, Aristizabal G, Martinez JW, Revelo D, De la Hoz F, Boshell J....In 1995, the first Venezuelan equine encephalitis (VEE) outbreak in Colombia in 22 years caused an estimated 75,000 human cases, 3000 with neurologic complications and 300 fatal, in La Guajira State. Of the state's estimated 50,000 equines, 8% may have died. An epizootic IC virus, probably introduced from Venezuela, was rapidly amplified among unvaccinated equines. Record high rainfall, producing high densities of vector Aedes taeniorhynchus, led to extensive epidemic transmission (30% attack rate) in the four affected municipalities. Native Wayuu Indians, constituting 24% of the state's popul...
Tulman ER, Delhon G, Afonso CL, Lu Z, Zsak L, Sandybaev NT, Kerembekova UZ, Zaitsev VL, Kutish GF, Rock DL.Here we present the genomic sequence of horsepox virus (HSPV) isolate MNR-76, an orthopoxvirus (OPV) isolated in 1976 from diseased Mongolian horses. The 212-kbp genome contained 7.5-kbp inverted terminal repeats and lacked extensive terminal tandem repetition. HSPV contained 236 open reading frames (ORFs) with similarity to those in other OPVs, with those in the central 100-kbp region most conserved relative to other OPVs. Phylogenetic analysis of the conserved region indicated that HSPV is closely related to sequenced isolates of vaccinia virus (VACV) and rabbitpox virus, clearly grouping to...
Field H, de Jong C, Melville D, Smith C, Smith I, Broos A, Kung YH, McLaughlin A, Zeddeman A.Hendra virus is a recently emerged zoonotic agent in Australia. Since first described in 1994, the virus has spilled from its wildlife reservoir (pteropid fruit bats, or 'flying foxes') on multiple occasions causing equine and human fatalities. We undertook a three-year longitudinal study to detect virus in the urine of free-living flying foxes (a putative route of excretion) to investigate Hendra virus infection dynamics. Pooled urine samples collected off plastic sheets placed beneath roosting flying foxes were screened for Hendra virus genome by quantitative RT-PCR, using a set of primers a...
Broder CC, Xu K, Nikolov DB, Zhu Z, Dimitrov DS, Middleton D, Pallister J, Geisbert TW, Bossart KN, Wang LF.Hendra virus and Nipah virus are bat-borne paramyxoviruses that are the prototypic members of the genus Henipavirus. The henipaviruses emerged in the 1990s, spilling over from their natural bat hosts and causing serious disease outbreaks in humans and livestock. Hendra virus emerged in Australia and since 1994 there have been 7 human infections with 4 case fatalities. Nipah virus first appeared in Malaysia and subsequent outbreaks have occurred in Bangladesh and India. In total, there have been an estimated 582 human cases of Nipah virus and of these, 54% were fatal. Their broad species tropis...
Castillo-Olivares J, Wood J.West Nile virus (WNV) is a flavivirus closely related to Japanese encephalitis and St. Louis encephalitis viruses that is primarily maintained in nature by transmission cycles between mosquitoes and birds. Occasionally, WNV infects and causes disease in other vertebrates, including humans and horses. West Nile virus has re-emerged as an important pathogen as several recent outbreaks of encephalomyelitis have been reported from different parts of Europe in addition to the large epidemic that has swept across North America. This review summarises the main features of WNV infection in the horse, ...
Carrera JP, Forrester N, Wang E, Vittor AY, Haddow AD, López-Vergès S, Abadía I, Castaño E, Sosa N, Báez C, Estripeaut D, Díaz Y, Beltrán D....The eastern equine encephalitis (EEE) and Venezuelan equine encephalitis (VEE) viruses are pathogens that infect humans and horses in the Americas. Outbreaks of neurologic disease in humans and horses were reported in Panama from May through early August 2010. Methods: We performed antibody assays and tests to detect viral RNA and isolate the viruses in serum samples from hospitalized patients. Additional cases were identified with enhanced surveillance. Results: A total of 19 patients were hospitalized for encephalitis. Among them, 7 had confirmed EEE, 3 had VEE, and 1 was infected with both ...
Olson JG, Ksiazek TG, Gubler DJ, Lubis SI, Simanjuntak G, Lee VH, Nalim S, Juslis K, See R.Sera were collected from humans, cattle, horses, goats, ducks, chickens, wild birds, bats and rats in Lombok, Indonesia, and were tested by haemagglutination inhibition (HI) for antibodies to JE, ZIKA, CHIK and RR. Selected sera were tested by microneutralization tests for antibodies to the following viruses: JE, ZIKA, MVE, TMU, LGT, KUN, SEP, DEN-2, CHIK, RR, GET, SIN, BUN, BAT and BAK. Human sera had JE HI antibody in 135 (30%) of 446 tested. Neutralization tests indicated that DEN-2, ZIKA, TMU, KUN and SEP may have caused flavivirus infections. Antibodies to other arboviruses tested for wer...
Daly JM, Lai AC, Binns MM, Chambers TM, Barrandeguy M, Mumford JA.Evolution of equine influenza a H3N8 viruses was examined by antigenic and genetic analysis of a collection isolates from around the world. It was noted that antigenic and genetic variants of equine H3N8 viruses cocirculate, and in particular that variants currently circulating in Europe and the USA are distinguishable from one another both in terms of antigenic reactivity and genetic structure of the HA1 portion of the haemagglutinin (HA) molecule. Whilst the divergent evolution of American and European isolates may be due to geographical isolation of the two gene pools, some mixing is believ...
Leroux C, Cadoré JL, Montelaro RC.Equine Infectious Anemia Virus (EIAV) is a lentivirus, of the Retrovirus family, with an almost worldwide distribution, infecting equids. It causes a persistent infection characterized by recurring febrile episodes associating viremia, fever, thrombocytopenia, and wasting symptoms. The disease is experimentally reproducible by inoculation of Shetland ponies or horses with EIAV pathogenic strains. Among lentiviruses, EIAV is unique in that, despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever ...
Valerio L, Marini F, Bongiorno G, Facchinelli L, Pombi M, Caputo B, Maroli M, Della Torre A.Knowledge of the frequency of contact between a mosquito species and its different hosts is essential to understand the role of each vector species in the transmission of diseases to humans and/or animals. However, no data are so far available on the feeding habits of Aedes albopictus in Italy or in other recently colonized temperate regions of Europe, due to difficulties in collecting blood-fed females of this diurnal and exophilic species. We analyzed Ae. albopictus host-feeding patterns in two urban and two rural sites within the area of Rome (Italy). Ae. albopictus was collected using stic...
Boyle AG, Timoney JF, Newton JR, Hines MT, Waller AS, Buchanan BR.This consensus statement update reflects our current published knowledge and opinion about clinical signs, pathogenesis, epidemiology, treatment, complications, and control of strangles. This updated statement emphasizes varying presentations in the context of existing underlying immunity and carrier states of strangles in the transmission of disease. The statement redefines the "gold standard" for detection of possible infection and reviews the new technologies available in polymerase chain reaction diagnosis and serology and their use in outbreak control and prevention. We reiterate the impo...
Thorpe CT, Clegg PD, Birch HL.Tendon injury is one of the most common causes of wastage in the performance horse; the majority of tendon injuries occur to the superficial digital flexor tendon (SDFT) whereas few occur to the common digital extensor tendon. This review outlines the epidemiology and aetiology of equine tendon injury, reviews the different functions of the tendons in the equine forelimb and suggests possible reasons for the high rate of failure of the SDFT. An understanding of the mechanisms leading to matrix degeneration and subsequent tendon gross failure is the key to developing appropriate treatment and p...
Murcia PR, Baillie GJ, Daly J, Elton D, Jervis C, Mumford JA, Newton R, Parrish CR, Hoelzer K, Dougan G, Parkhill J, Lennard N, Ormond D, Moule S....Determining the evolutionary basis of cross-species transmission and immune evasion is key to understanding the mechanisms that control the emergence of either new viruses or novel antigenic variants with pandemic potential. The hemagglutinin glycoprotein of influenza A viruses is a critical host range determinant and a major target of neutralizing antibodies. Equine influenza virus (EIV) is a significant pathogen of the horse that causes periodical outbreaks of disease even in populations with high vaccination coverage. EIV has also jumped the species barrier and emerged as a novel respirator...
Morales MA, Barrandeguy M, Fabbri C, Garcia JB, Vissani A, Trono K, Gutierrez G, Pigretti S, Menchaca H, Garrido N, Taylor N, Fernandez F, Levis S....West Nile virus (WNV) was isolated from the brains of 3 horses that died from encephalitis in February 2006. The horses were from different farms in central Argentina and had not traveled outside the country. This is the first isolation of WNV in South America.
Leroy G, Mary-Huard T, Verrier E, Danvy S, Charvolin E, Danchin-Burge C.Effective population sizes of 140 populations (including 60 dog breeds, 40 sheep breeds, 20 cattle breeds and 20 horse breeds) were computed using pedigree information and six different computation methods. Simple demographical information (number of breeding males and females), variance of progeny size, or evolution of identity by descent probabilities based on coancestry or inbreeding were used as well as identity by descent rate between two successive generations or individual identity by descent rate. Results: Depending on breed and method, effective population sizes ranged from 15 to 133 ...
Weese JS, Archambault M, Willey BM, Hearn P, Kreiswirth BN, Said-Salim B, McGeer A, Likhoshvay Y, Prescott JF, Low DE.Methicillin-resistant Staphylococcus aureus (MRSA) infection was identified in 2 horses treated at a veterinary hospital in 2000, prompting a study of colonization rates of horses and associated persons. Seventy-nine horses and 27 persons colonized or infected with MRSA were identified from October 2000 to November 2002; most isolations occurred in a 3-month period in 2002. Twenty-seven (34%) of the equine isolates were from the veterinary hospital, while 41 (51%) were from 1 thoroughbred farm in Ontario. Seventeen (63%) of 27 human isolates were from the veterinary hospital, and 8 (30%) were ...
Reperant LA, Rimmelzwaan GF, Kuiken T.Highly pathogenic avian influenza viruses of subtype H5N1 are remarkable because of their expanding non-avian host range and wide tissue tropism. They have caused severe or fatal respiratory and extra-respiratory disease in seven naturally infected species of carnivore. However, they are not unique in their ability to cross the species barrier, to cause clinical disease and mortality, or to replicate in extra-respiratory organs. Low pathogenic avian influenza viruses have crossed from birds to swine, horses, harbour seals, whales and mink; have resulted in severe respiratory disease and mortal...
