Disease transmission in horses refers to the spread of infectious agents such as bacteria, viruses, fungi, and parasites among equine populations. These pathogens can be transmitted through various routes, including direct contact, vector-borne transmission, or environmental exposure. Factors influencing disease transmission include horse density, management practices, and biosecurity measures. Understanding the mechanisms and conditions that facilitate the spread of diseases is essential for developing effective prevention and control strategies. This page compiles peer-reviewed research studies and scholarly articles that investigate the modes of transmission, risk factors, and management practices related to infectious diseases in horses.
Woo PCY, Mheiri FA, Cavalleri J, Joseph S, Tang JYM, Joseph M, Tsang CC, Lau SKP, Wernery U.Epizootic lymphangitis (EL) is a highly prevalent and contagious infectious disease affecting horses in many parts of Ethiopia caused by Histoplasma capsulatum sensu lato ('var. farciminosum'). In this study, 12 suspected isolates of H. capsulatum sensu lato or yeasts unidentified by conventional biochemical tests isolated from Ethiopian horses with EL were characterised by ITS sequencing. Six of the 12 isolates were identified to be members of H. capsulatum sensu lato and the other six were Pichia kudriavzevii (synonym: Candida krusei) (n = 3), Trichosporon asahii (n = 1), Geotrichum silv...
Scholtz M, Guthrie AJ, Newton R, Schulman ML.Three bacteria extensively acknowledged as venereal pathogens with the potential to induce endometritis include Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), specific strains of Pseudomonas aeruginosa, and certain capsule types of Klebsiella pneumoniae. The United Kingdom's Horserace Betting Levy Board recommends pre-breeding screening for these bacteria in their International Codes of Practice and >20 000 samples are tested per annum in the United Kingdom alone. While the pathogenesis and regulatory importance of CEM are well established, an evaluation...
Martínez-Sáez L, Pala S, Marín-García PJ, Llobat L.Toxoplasmosis is one of the most common parasitic zoonoses and represents a significant health risk for humans, especially for immunodeficient patients. The main transmission route is by oral uptake of oocysts and consumption of undercooked meat of infected animals. Different species have been evaluated as possible reservoirs of the parasite, but few studies have been carried out to examine the role of horses in transmission of the disease. Given the proximity of these animals to humans and the widespread consumption of their meat in many countries, including the Mediterranean basin, it is imp...
Ringo RS, Choonnasard A, Okabayashi T, Saito A. can establish persistent infections in animals such as equids, pigs, nonhuman primates, rodents, and possums. Some can even cause overt and severe diseases such as Equine Arteritis in horses and Porcine Reproductive and Respiratory Syndrome in pigs, leading to huge economic losses. have evolved viral proteins to antagonize the host cell's innate immune responses by inhibiting type I interferon (IFN) signaling, assisting viral evasion and persistent infection. So far, the role of the glycoprotein 5 (GP5) protein in IFN signaling inhibition remains unclear. Here, we investigated the inhibito...
White NA, Flynn K.The purpose of the study was to assess the challenges faced by state animal health officials (SAHOs) when managing equine disease outbreaks. Methods: A survey was conducted to assess SAHOs' collaboration with horse owners and practicing veterinarians to provide biosecurity and infection disease control. It was sent to 180 email addresses listed in the Equine Disease Communication Center website database. The responses in each category for each question were tabulated and reported as a percentage. Results: There were 72 survey responses from 45 states. The number of states responding suggested ...
Morais DA, Nunes BC, Barnabé NNC, Anjos DM, Bezerra CS, Costa DF, Santos CSAB, Azevedo SS, Alves CJ.Leptospirosis is an anthropozoonosis of economic and public health importance, caused by bacteria of the genus Leptospira. Horses are deemed important in its transmission chain due to their proximity to humans, and because the species is often asymptomatic, making these animals potential silent reservoirs. In this context, the objectives of this study were to determine the prevalence of seropositive horses for Leptospira spp., and to identify the presence of Leptospira spp. serogroups and antibody titers, the occurrence of areas with higher density of infection cases and demographic characteri...
Fairbanks EL, Daly JM, Tildesley MJ.Most mathematical models that assess the vectorial capacity of disease-transmitting insects typically focus on the influence of climatic factors to predict variations across different times and locations, or examine the impact of vector control interventions to forecast their potential effectiveness. We combine features of existing models to develop a novel model for vectorial capacity that considers both climate and vector control. This model considers how vector control tools affect vectors at each stage of their feeding cycle, and incorporates host availability and preference. Applying this...
Kabir A, Lamichhane B, Habib T, Adams A, El-Sheikh Ali H, Slovis NM, Troedsson MHT, Helmy YA.The equine industry holds substantial economic importance not only in the USA but worldwide. The occurrence of various infectious bacterial diseases in horses can lead to severe health issues, economic losses, and restrictions on horse movement and trade. Effective management and control of these diseases are therefore crucial for the growth and sustainability of the equine industry. While antibiotics constitute the primary treatment strategy for any bacterial infections in horses, developing resistance to clinically important antibiotics poses significant challenges to equine health and welfa...
Streng K, Hakze-van der Honing RW, Graham H, van Oort S, de Best PA, Abourashed A, van der Poel WHM.Zoonotic arboviruses (arthropod-borne) of the Orthoflavivirus genus, such as West Nile virus (WNV), Usutu virus (USUV) and Tick-borne encephalitis virus (TBEV), are emerging in Northwestern Europe and pose a threat to both human and animal health. In the Netherlands, passive symptomatic surveillance (notification of clinical cases) in horses is one of the main pillars for the early detection of WNV. For such passive surveillance to work properly, horse owners and veterinarians need to recognize symptoms and report suspected cases to the authorities. Currently, little is known about the seropre...
Maeda M, Abe M, Aoshima K, Kobayashi A, Fukushi H, Kimura T.Equine herpesvirus-1 (EHV-1) causes respiratory diseases, abortion, and encephalomyelitis in horses. The EHV-1 immediate-early (IE) protein, essential for viral replication, is transactivated by the binding of a multiprotein complex including the open reading frame 12 (ORF12) and some host factors to the IE promoter region. Promoter-associated non-coding RNAs (pancRNAs), which are transcribed from bidirectional promoters, regulate the transcription of neighboring genes in mammals and pathogens. In this study, we identified a novel pancRNA transcribed from across the areas of the 5'-untranslate...
Rar V, Marchenko V, Suntsova O, Epikhina T, Tikunov A, Meltsov I, Fedorets V, Igolkina Y, Kozlova I, Tikunova N.Equine piroplasmosis (EP) is a global worldwide infection, which can lead to the death of animals. Despite the causative agents of EP being well studied, there are no data on the distribution and genetic characteristics of EP agents in any region of Russia. In this study, blood samples from 750 horses from Novosibirsk province, Irkutsk province, and Altai region of Russian Siberia were examined for the presence of EP agents. Theileria equi and Babesia caballi were detected in all examined regions, with mean prevalence rates of 60.4% and 7.2%, respectively. The identified pathogens were genetic...
Marques CDP, da Silva BWS, Nogueira YVS, Bezerra TL, Borges-Silva W, Soares RM, Gondim LFP.Sarcocystis bertrami (synonym: Sarcocystis fayeri) is a coccidian parasite that infects horses and donkeys in several countries. Dogs are known as definitive hosts of the parasite, however, the patent period is not well defined, and S. bertrami shed by dogs has never been confirmed by molecular methods. Here we investigated the shedding of S. bertrami by experimentally infected dogs and examined the excreted parasites by morphological and molecular tools. Three dogs of small breeds (one Yorkshire terrier and two miniature Pinschers) were acquired with ages of 30 and 60 days and were exclusivel...
Diekmann I, Blazejak K, Krücken J, Strube C, von Samson-Himmelstjerna G.Surveillance of Strongylus vulgaris and other Strongylus spp. in equids is important for targeted intervention in parasite control, requiring reliable routine diagnostic methods. Objective: Comparing morphological examination and PCR analyses of larval cultures to identify Strongylus spp. species based on German diagnostic samples from 2018. Methods: Method comparison. Methods: During the routine diagnostic investigations, in total 712 strongyle-egg positive equine faecal samples were cultured. Third-stage larvae (L3) were morphologically differentiated. For molecular validation, samples were ...
An Q, Li Y, Sun Z, Gao X, Wang H.Equine Infectious Anemia (EIA) is a vector-borne persistent viral infection in equine animals. The EIA is characterized by recurrent fever, thrombocytopenia, depression, anemia, rapid weight loss, and lower body edema. Control of EIA is achieved through the elimination or isolation of infected animals, resulting in significant economic losses. In recent years, many countries in Europe have experienced outbreaks of EIA, which could potentially develop into a new wave of epidemic and pose a significant threat to the healthy development of the equine industry. This study utilized spatiotemporal a...
Pusterla N, Lawton K, Barnum S.In populations of healthy show horses, the subclinical transmission and circulation of respiratory pathogens can lead to disease outbreaks. Due to recent outbreaks of equine herpesvirus-1 myeloencephalopathy (EHM) in the USA and Europe, many show organizers have instituted various biosecurity protocols such as individual horse testing, monitoring for early clinical disease and increasing hygiene and cleanliness protocols. The aim of this study was to determine the accuracy of detecting EHV-1 in the various environmental samples collected from the stalls of subclinical shedders. Four healthy ad...
Ryt-Hansen P, Johansen VK, Cuicani MM, Larsen LE, Hansen S.Equine herpesvirus 4 (EHV-4) causes respiratory disease in horses, and the virus is considered endemic in the global equine population. However, outbreaks can occur when several horses are gathered in relation to shows, competitions, breeding units and at hospitals. In the spring year 2022, an EHV-4 outbreak occurred at the Large Animal Teaching Hospital, University of Copenhagen, Denmark. Nine horses were tested EHV-4 positive during the outbreak, which lasted approx. seven weeks. In addition, a tenth horse "Eq10" tested EHV-4 positive almost three weeks after the last of the outbreak horses ...
Sedgwick RL, ElBohy O, Daly JM.In this review, we explore how pseudotyped viruses (PVs) are being applied to the study of viruses affecting both humans and horses. For the purposes of this review, we define PVs as non-replicative viruses with the core of one virus and the surface protein(s) of another and encapsulating a reporter gene such as luciferase. These 'reporter' PVs enable receptor-mediated entry into host cells to be quantified, and thus can be applied to study the initial stages of viral replication. They can also be used to test antiviral activity of compounds and measure envelope protein-specific antibodies in ...
Germann JA, O'Sullivan TL, Greer AL, Spence KL.Disease outbreaks present a significant challenge to horse health and welfare and the economic stability of horse industries internationally. This is a particular concern in Ontario, Canada, where there have been frequent outbreaks of respiratory infectious diseases among horses. Despite these risks, there has been limited research on whether Ontario horse owners engage in biosecurity measures sufficient to mitigate risk of equine diseases, and whether current events such as the COVID-19 pandemic influence attitudes towards equine biosecurity practices. Objective: To explore Ontario horse owne...
Ribeiro M, Gomes-Gonçalves S, Moreira G, Cardoso L, Mesquita JR.The life-cycle of the parasitic forms of Halicephalobus gingivalis is yet to be fully understood. In cases where there is evidence to support the presence of eggs from this parasite or its DNA in the faeces of equines, a thorough investigation of the clinical status and gastro-intestinal tract of the affected animals is warranted, as well as detailed descriptions of the employed coprological technique. Since reports of the identification of H. gingivalis eggs in faeces are sparse, objective measurements and high-quality images must be provided, in order to ensure optimal criteria for classific...
Carey KJ, Smith I, Barr J, Caruso S, Au GG, Hartley CA, Bailey KE, Perriam W, Broder CC, Gilkerson JR.Hendra virus (HeV) is lethal to horses and a zoonotic threat to humans in Australia, causing severe neurological and/or respiratory disease with high mortality. An equine vaccine has been available since 2012. Foals acquire antibodies from their dams by ingesting colostrum after parturition, therefore it is assumed that foals of mares vaccinated against HeV will have passive HeV antibodies circulating during the first several months of life until they are actively vaccinated. However, no studies have yet examined passive or active immunity against HeV in foals. Here, we investigated anti-HeV a...
Atabek B, Zhyldyz A, Aitakin K, Rysbek N, Jailobek O, Ahedor B, Mumbi NNM, Ma Y, Otgonsuren D, Perera WPPSI, Guswanto A, Sivakumar T, Yokoyama N.Equine piroplasmosis is caused by Theileria equi and Babesia caballi, which are hemoprotozoan parasites. Understanding the epidemiology and genotypes of T. equi and B. caballi is crucial for developing effective control strategies in endemic countries. However, the endemic status of these two parasite species remains uncertain in Kyrgyzstan due to lack of surveys. Our study, therefore, aimed to detect T. equi and B. caballi infections in Kyrgyzstan and identify their genotypes. Blood samples were collected from 226 horses across all seven provinces of Kyrgyzstan, namely Chuy, Issyk-Kul, Naryn,...
Öhrmalm J, Cholleti H, Theelke AK, Berg M, Gröndahl G.Equid alphaherpesvirus 1 (EHV-1) is a ubiquitous and significant viral pathogen in horses worldwide, causing a range of conditions, including fever, respiratory disease, abortion in pregnant mares and the severe neurological disease called equine herpes myeloencephalopathy (EHM). Despite that EHV-1 is a notifiable animal disease in Sweden, there is limited knowledge about the circulating strains. This study aimed to analyze the genetic diversity of EHV-1 strains in equine samples from different Swedish outbreaks by partial genome sequencing. Genotyping based on three selected open reading fram...
Grabatin M, Fux R, Zablotski Y, Goehring LS, Witte TS.Contagious equine metritis (CEM) is caused by Taylorella equigenitalis. It is a venereal disease that is detected in some breeds more than others and can cause temporary infertility with substantial costs for regular testing, sanitation and retesting. There was a perceived increase in T. equigenitalis-positive cases in Icelandic intact males where natural cover is common. Objective: We aimed to investigate the prevalence of T. equigenitalis in Icelandic intact males and compare to draught horse and Haflinger intact males. We hypothesised that prevalence of T. equigenitalis is higher in Iceland...
Lale D, Dirks EE, Preining I, Lyrakis M, Gömer A, Steinmann E, Cavalleri JV, Ramsauer AS.Equine parvovirus hepatitis (EqPV-H) can cause Theiler's disease and subclinical hepatitis in horses. Objective: Assess the frequency of subclinical EqPV-H infection in hospitalized horses and to study viral transmission by investigating potential shedding routes. Methods: One hundred sixteen equids, that presented to the University Equine Hospital of the University of Veterinary Medicine Vienna between February 2021 and March 2022, for causes other than hepatopathy. Methods: In this cross-sectional study, samples (serum, feces, nasal, and buccal swabs) of hospitalized horses were collected. S...
Nakajima K, Kasuya K, Senba H, Tagami K, Kinoshita Y, Niwa H.Strangles is a globally widespread, commonly diagnosed and important infectious disease of equids caused by Streptococcus equi subsp. equi. We performed whole genome sequencing of 19 S. equi isolates collected from imported horses at the Japanese border. Of these isolates, 15 isolates were obtained from clinical cases and 4 were from subclinical cases. The 19 isolates were grouped into 3 Bayesian analysis of population structure (BAPS) groups by the core genome single nucleotide polymorphism analysis corresponding to exporting country, SeM typing, or exporter of the horses. The 19 isolates pos...
Afify AF, Hassanien RT, El Naggar RF, Rohaim MA, Munir M.Equid herpesviruses (EHVs) are a group of highly impactful viral pathogens that affect horses, presenting a substantial risk to the global equine industry. Among these, equid herpesvirus-1 (EHV-1) primarily causes respiratory infections. However, its ability to spread to distant organs can lead to severe consequences such as abortion and neurological diseases. These viruses can enter a dormant phase, with minimal activity, and later reactivate to trigger active infections at any time. Recently, there has been a notable rise in the prevalence of a particularly devastating strains of EHV-1 known...
Williams RAJ, Criollo Valencia HA, López Márquez I, González González F, Llorente F, Jiménez-Clavero MÁ, Busquets N, Mateo Barrientos M....West Nile virus (WNV) is a re-emerging flavivirus, primarily circulating among avian hosts and mosquito vectors, causing periodic outbreaks in humans and horses, often leading to neuroinvasive disease and mortality. Spain has reported several outbreaks, most notably in 2020 with seventy-seven human cases and eight fatalities. WNV has been serologically detected in horses in the Community of Madrid, but to our knowledge, it has never been reported from wild birds in this region. To estimate the seroprevalence of WNV in wild birds and horses in the Community of Madrid, 159 wild birds at a wildli...
Ding J, Wang Y, Liang J, He Z, Zhai C, He Y, Xu J, Lei L, Mu J, Zheng M, Liu B, Shi M.Equine influenza (EI) is a severe infectious disease that causes huge economic losses to the horse industry. Spatial epidemiology technology can explore the spatiotemporal distribution characteristics and occurrence risks of infectious diseases, it has played an important role in the prevention and control of major infectious diseases in humans and animals. For the first time, this study conducted a systematic analysis of the spatiotemporal distribution of EI using SaTScan software and investigated the important environmental variables and suitable areas for EI occurrence using the Maxent mode...
Gonzalez-Obando J, Zuluaga-Cabrera A, Moreno I, Úsuga J, Ciuderis K, Forero JE, Diaz A, Rojas-Arbeláez C, Hernández-Ortiz JP, Ruiz-Saenz J.Equine influenza is a viral disease caused by the equine influenza virus (EIV), and according to the WOAH, it is mandatory to report these infections. In Latin America and Colombia, EIV risk factors have not been analyzed. The objective of this research is to perform an epidemiological and molecular analysis of the EIV in horses with respiratory symptoms from 2020 to 2023 in Colombia. Molecular EIV detection was performed using RT-qPCR and nanopore sequencing. A risk analysis was also performed via the GEE method. A total of 188 equines with EIV respiratory symptoms were recruited. The positiv...
Houben RMAC, Newton JR, van Maanen C, Waller AS, Sloet van Oldruitenborgh-Oosterbaan MM, Heesterbeek JAP.Strangles, a disease caused by infection with Streptococccus equi subspecies equi (S. equi), is endemic worldwide and one of the most frequently diagnosed infectious diseases of horses. Recent work has improved our knowledge of key parameters of transmission dynamics, but important knowledge gaps remain. Our aim was to apply mathematical modelling of S. equi transmission dynamics to prioritise future research areas, and add precision to estimates of transmission parameters thereby improving understanding of S. equi epidemiology and quantifying the control effort required. A compartmental deter...
de Vos CJ, Hoek CA, Nodelijk G.African horse sickness (AHS) is a vector-borne viral disease of equines that is transmitted by Culicoides spp. and can have severe consequences for the horse industry in affected territories. A study was performed to assess the risk of introducing AHS virus (AHSV) into the Netherlands (P_AHS) by international equine movements. The goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and (c) the effectiveness of measures to prevent introduction of AHSV. Countries worldwide were grouped ...
Yadav PD, Albariño CG, Nyayanit DA, Guerrero L, Jenks MH, Sarkale P, Nichol ST, Mourya DT.A virus isolated from a sick horse from India in 2008 was confirmed by next-generation sequencing analysis to be equine encephalosis virus (EEV). EEV in India is concerning because several species of Culicoides midge, which play a major role in EEV natural maintenance and transmission, are present in this country.
Venter M, Human S, van Niekerk S, Williams J, van Eeden C, Freeman F.In 2010, lineage 1 West Nile virus was detected in South Africa in the brain of a pregnant mare that succumbed to neurologic disease and in her aborted fetus, suggesting an association with abortion in horses. All West Nile virus strains previously detected in horses and humans in South Africa were lineage 2.
Chapman GE, Sherlock K, Hesson JC, Blagrove MSC, Lycett GJ, Archer D, Solomon T, Baylis M.There has been no evidence of transmission of mosquito-borne arboviruses of equine or human health concern to date in the UK. However, in recent years there have been a number of outbreaks of viral diseases spread by vectors in Europe. These events, in conjunction with increasing rates of globalisation and climate change, have led to concern over the future risk of mosquito-borne viral disease outbreaks in northern Europe and have highlighted the importance of being prepared for potential disease outbreaks. Here we assess several UK mosquito species for their potential to transmit arboviruses ...
Gildea S, Arkins S, Cullinane A.Outbreaks of equine influenza (EI) in endemic populations continue to cause economic loss despite widespread vaccination. Objective: To identify the key management and environmental factors that determine the risk of horses contracting EI in an endemic country and to identify control strategies. Methods: Real time-polymerase chain reaction (RT-PCR), virus isolation and haemagglutination inhibition were carried out on nasopharyngeal swabs and clotted blood samples collected from horses and ponies showing signs of respiratory disease. On premises where a diagnosis of EI was confirmed, the attend...
Watson J, Daniels P, Kirkland P, Carroll A, Jeggo M.In August 2007 Australia experienced its first outbreak of equine influenza. The disease occurred first in a quarantine station for imported horses near Sydney and subsequently escaped into the general horse population. After an extensive campaign the disease was eradicated and Australia is again recognised as free of this disease. Equine influenza was then, and is now, recognised to be the major disease risk associated with live horse imports into Australia and measures designed to mitigate this risk formed the basis of the quarantine protocols then in place. Subsequent investigations into th...
Spier SJ, Leutenegger CM, Carroll SP, Loye JE, Pusterla JB, Carpenter TE, Mihalyi JE, Madigan JE.To develop and use a sensitive molecular assay for detecting the phospholipase D (PLD) exotoxin gene of Corynebacterium pseudotuberculosis in an attempt to identify insect vectors that may be important in transmission of clinical disease in horses. Methods: 2,621 flies of various species. Methods: A real-time polymerase chain reaction (PCR)-based fluorogenic 5' nuclease (TaqMan) system (ie, TaqMan PCR assay) was developed for the detection of the PLD gene in insects. Flies were collected monthly (May to November 2002) from 5 farms in northern California where C. pseudotuberculosis infection in...
Diarra M, Fall M, Fall AG, Diop A, Seck MT, Garros C, Balenghien T, Allène X, Rakotoarivony I, Lancelot R, Mall I, Bakhoum MT, Dosum AM, Ndao M....The African horse sickness epizootic in Senegal in 2007 caused considerable mortality in the equine population and hence major economic losses. The vectors involved in the transmission of this arbovirus have never been studied specifically in Senegal. This first study of the spatial and temporal dynamics of the Culicoides (Diptera: Ceratopogonidae) species, potential vectors of African horse sickness in Senegal, was conducted at five sites (Mbao, Parc Hann, Niague, Pout and Thies) in the Niayes area, which was affected by the outbreak. Methods: Two Onderstepoort light traps were used at each s...
Damborg P, Marskar P, Baptiste KE, Guardabassi L.The objective of this longitudinal study was to investigate the occurrence and genetic background of faecal Escherichia coli resistant to cefotaxime (CTX) in horses receiving broad-spectrum antimicrobial prophylaxis after admission to a veterinary teaching hospital. The ten horses enrolled in the study were treated with cefquinome either alone (n=4) or in combination with metronidazole (n=3) or other antimicrobial agents (n=3). CTX-resistant coliforms in faeces collected before, during and after treatment were quantified on selective MacConkey agar supplemented with CTX, and a colony isolated ...
Leblond A, Sandoz A, Lefebvre G, Zeller H, Bicout DJ.Geographic information system and remote sensing technologies were used to identify landscape features associated with risk of West Nile virus transmission as defined by the presence of confirmed horse cases. SPOT-4 images of Camargue area were used to generate a map of landscape categories of epidemic foci and the geographic information system was employed to determine the proportion of landscape components surrounding 10 horse case sites and 17 control sites. The spatio-temporal analysis of the cases outbreak gave the best results for a spatial window of 9 km and a temporal window of 18 days...
Bamberg WM, Pape WJ, Beebe JL, Nevin-Woods C, Ray W, Maguire H, Nucci J, Massung RF, Gershman K.Coxiella burnetii is a bacterium located worldwide that can cause Q fever when inhaled. We describe an outbreak of Q fever associated with a horse-boarding ranch that had acquired two herds of goats. We conducted case finding and cohort studies among persons who boarded horses on the ranch and ranchers and among residents in the surrounding community, and conducted sampling of the goats and environment, to determine risk factors for infection and guide public health interventions. Sixty-six ranchers and persons who boarded horses on the ranch were interviewed; 62 (94%) were not professional ra...
Harvey AM, Meggiolaro MN, Hall E, Watts ET, Ramp D, Šlapeta J.Australia has over 400,000 wild horses, the largest wild equid population in the world, scattered across a range of different habitats. We hypothesised that wild horse populations unexposed to anthelmintics would have a high prevalence of infections. Verminous endarteritis and colic due to migrating larvae is now absent or unreported in domestic horses in Australia, yet wild horses may pose a risk for its re-emergence. A total of 289 faecal egg counts (FECs) were performed across six remote wild horse populations in south-east Australia, of varying densities, herd sizes and habitats. Total s...
Álvarez-Narváez S, Giguère S, Cohen N, Slovis N, Vázquez-Boland JA.Multidrug resistance has been detected in the animal and zoonotic human pathogen Rhodococcus equi after mass macrolide/rifampin antibioprophylaxis in endemically affected equine farms in the United States. Multidrug-resistant (MDR) R. equi emerged upon acquisition of pRERm46, a conjugative plasmid conferring resistance to macrolides, lincosamides, streptogramins, and, as we describe, tetracycline. Phylogenomic analyses indicate that the increasing prevalence of MDR R. equi since it was first documented in 2002 is caused by a clone, R. equi 2287, attributable to coselection of pRErm46 with a ch...
Campos RK, Brum MC, Nogueira CE, Drumond BP, Alves PA, Siqueira-Lima L, Assis FL, Trindade GS, Bonjardim CA, Ferreira PC, Weiblen R, Flores EF....During the last bovine vaccinia (BV) outbreaks, several Vaccinia virus (VACV) strains were isolated and characterised, revealing significant polymorphisms between strains, even within conserved genes. Although the epidemiology of VACV has been studied in BV outbreaks, there is little data about the circulation of the Brazilian VACV isolates. This study describes the genetic and biological characterisation of two VACV isolates, Pelotas 1 virus (P1V) and Pelotas 2 virus (P2V), which were obtained concomitantly from a horse affected by severe cutaneous disease. Despite being isolated from the sam...
Laperriere V, Brugger K, Rubel F.The West Nile virus (WNV) is an arthropod-borne virus (arbovirus) circulating in a natural transmission cycle between mosquitoes (enzootic vectors) and birds (amplifying hosts). Additionally, mainly horses and humans (dead-end hosts) may be infected by blood-feeding mosquitoes (bridge vectors). We developed an epidemic model for the simulation of the WNV dynamics of birds, horses and humans in the U.S., which we apply to the Minneapolis metropolitan area (Minnesota). The SEIR-type model comprises a total of 19 compartments, that are 4 compartments for mosquitoes and 5 compartments or health st...
Björnsdóttir S, Harris SR, Svansson V, Gunnarsson E, Sigurðardóttir ÓG, Gammeljord K, Steward KF, Newton JR, Robinson C, Charbonneau ARL....Iceland is free of the major infectious diseases of horses. However, in 2010 an epidemic of respiratory disease of unknown cause spread through the country's native horse population of 77,000. Microbiological investigations ruled out known viral agents but identified the opportunistic pathogen subsp. () in diseased animals. We sequenced the genomes of 257 isolates of to differentiate epidemic from endemic strains. We found that although multiple endemic clones of were present, one particular clone, sequence type 209 (ST209), was likely to have been responsible for the epidemic. Concurrent ...
Leblond A, Pradier S, Pitel PH, Fortier G, Boireau P, Chadoeuf J, Sabatier P.Anaplasmosis is caused by the bacterium Anaplasma phagocytophilum and transmitted by Ixodes spp. ticks. According to some reports the disease can be introduced into disease-free zones by migrating birds. The purpose of this study was to evaluate the seroprevalence of A. phagocytophilum in horses in the Camargue. Data concerning 424 horses were gathered and the sera were tested for A. phagocytophilum and for piroplasmoses using an enzyme-linked immunosorbent assay and a complement fixation test, respectively. The seroprevalence rates were 11.3 % for A. phagocytophilum, 64.4 % for Theileria equi...
Haussler KK.The clinical assessment of pain is subjective; therefore, variations exist between practitioners in their ability to identify and localize pain. Due to differing interpretations of the signs or severity of pain equine practitioners may assign varying levels of clinical significance and treatment options. There is a critical need to develop better tools to qualify and quantify pain in horses. Palpation is the most common method to detect local tenderness or sensitivity. To quantify this applied pressure, pressure algometry has been used to gradually apply pressure over specified landmarks until...
Roth D, Henry B, Mak S, Fraser M, Taylor M, Li M, Cooper K, Furnell A, Wong Q, Morshed M.In 2009, an expansion of West Nile virus (WNV) into the Canadian province of British Columbia was detected. Two locally acquired cases of infection in humans and 3 cases of infection in horses were detected by ELISA and plaque-reduction neutralization tests. Ten positive mosquito pools were detected by reverse transcription PCR. Most WNV activity in British Columbia in 2009 occurred in the hot and dry southern Okanagan Valley. Virus establishment and amplification in this region was likely facilitated by above average nightly temperatures and a rapid accumulation of degree-days in late summer....
Deardorff ER, Weaver SC.The mosquito Culex (Melanoconion) taeniopus is a proven vector of enzootic Venezuelan equine encephalitis virus (VEEV) subtype IE in Central America. It has been shown to be highly susceptible to infection by this subtype, and conversely to be highly refractory to infection by other VEEV subtypes. During the 1990s in southern coastal Mexico, two VEE epizootics in horses were attributed to subtype IE VEEV. These outbreaks were associated with VEEV strains with an altered infection phenotype for the epizootic mosquito vector, Aedes (Ochlerotatus) taeniorhynchus. To determine the infectivity for ...
Mughini-Gras L, Mulatti P, Severini F, Boccolini D, Romi R, Bongiorno G, Khoury C, Bianchi R, Montarsi F, Patregnani T, Bonfanti L, Rezza G....In Italy, West Nile virus (WNV) equine outbreaks have occurred annually since 2008. Characterizing WNV vector habitat requirements allows for the identification of areas at risk of viral amplification and transmission. Maxent-based ecological niche models were developed using literature records of 13 potential WNV Italian vector mosquito species to predict their habitat suitability range and to investigate possible geographical associations with WNV equine outbreak occurrence in Italy from 2008 to 2010. The contribution of different environmental variables to the niche models was also assessed...
Reif JS, Webb PA, Monath TP, Emerson JK, Poland JD, Kemp GE, Cholas G.In 1982-1983, an epizootic of vesicular stomatitis occurred in the western United States. Veterinarians, research workers, and regulatory personnel who were exposed to vesicular stomatitis virus were examined for patterns of human infection and prevalence of vesicular stomatitis New Jersey serotype neutralizing antibody. Insight into the mechanism of transmission was sought by comparing activities of antibody-positive and antibody-negative persons. A statistically significant risk factor was a history of infected animals sneezing in the face of serosurvey participants. Elevated odds ratios wer...
Guthrie AJ, Stevens KB, Bosman PP.Equine-2 influenza A virus (H3N8) infection first occurred among naïve horses in South Africa in December 1986. The virus was introduced following the importation of six horses from the United States of America. While the release of in-contact horses from quarantine three days after the arrival of these six horses played a role in the rapid spread of the disease in South Africa, other outbreaks of disease were associated with viral introduction by personnel or contaminated instruments. The control measures and implications of the introduction of equine influenza to South Africa are also discu...
Timoney PJ, McCollum WH, Murphy TW, Roberts AW, Willard JG, Carswell GD.The carrier state has been confirmed virologically in Thoroughbred and non-Thoroughbred stallions naturally infected with equine arteritis virus (EAV). Short-term or convalescent and long-term carriers occur. The frequency rate of the long-term carrier state in Thoroughbreds was high, averaging 33.9% among the three groups of stallions under study. While the convalescent carrier state only lasted a few weeks after clinical recovery, the long-term carrier state could persist for years. There was evidence, however, that not all such carriers might remain persistently infected for life. Carrier s...
Powell DG, Watkins KL, Li PH, Shortridge KF.Equine-2 influenza virus A (H3N8) infection occurred among vaccinated thoroughbred horses in Hong Kong during November and December 1992. The outbreak was unique in that it occurred among a large population stabled under intensive conditions. It resulted in the postponement of seven race meetings over a period of 32 days. The outbreak originated after the importation of horses 25 to 32 days before any clinical signs were reported. Vaccination did not prevent 75 per cent of the population from becoming infected, and half the infected horses developed clinical signs. Vaccination did, however, co...
Marsh GA, Todd S, Foord A, Hansson E, Davies K, Wright L, Morrissy C, Halpin K, Middleton D, Field HE, Daniels P, Wang LF.Bat-to-horse transmission of Hendra virus has occurred at least 14 times. Although clinical signs in horses have differed, genome sequencing has demonstrated little variation among the isolates. Our sequencing of 5 isolates from recent Hendra virus outbreaks in horses found no correlation between sequences and time or geographic location of outbreaks.
Xu Z, Kang X, Han P, Du P, Li L, Zheng A, Deng C, Qi J, Zhao X, Wang Q, Liu K, Gao GF.The origin and host range of SARS-CoV-2, the causative agent of coronavirus disease 2019 (COVID-19), are important scientific questions as they might provide insight into understanding of the potential future spillover to infect humans. Here, we tested the binding between equine angiotensin converting enzyme 2 (eqACE2) and the receptor binding domains (RBDs) of SARS-CoV, SARS-CoV-2 prototype (PT) and variant of concerns (VOCs), as well as their close relatives bat-origin coronavirus (CoV) RaTG13 and pangolin-origin CoVs GX/P2V/2017 and GD/1/2019. We also determined the crystal structures of eq...
Kecerova Z, Cizek A, Nyc O, Krutova M.Clostridium difficile has been recovered from the faeces of several animal species as well as horses. Between April 2015 and October 2016, 213 samples of faeces from non-hospitalized (n = 138) and hospitalized horses (n = 75) were investigated and eighteen C. difficile isolates were cultured using an enrichment method. Sixteen C. difficile positive samples were identified from hospitalised horses (p < 0.01). Molecular typing revealed seven ribotypes and sequence types (RT033/ST11 n = 8, 44.4%; RT081/ST9 n = 4, 22.2%; RT009/ST3 n = 2, 11.1%; RT003/ST12 n = 1, 5.6%;...
Silva RO, Ribeiro MG, Palhares MS, Borges AS, Maranhão RP, Silva MX, Lucas TM, Olivo G, Lobato FC.Toxin detection and screening could contribute to knowledge of the transmission patterns, risk factors and epidemiology of Clostridium difficile and Clostridium perfringens. Objective: To isolate C. difficile and C. perfringens and to detect A/B toxins in faecal samples from diarrhoeic and nondiarrhoeic foals. Methods: Cross-sectional observational study. Methods: A total of 153 samples from foals were collected: 139 samples from farms and 14 samples from diarrhoeic foals admitted to a veterinary hospital. The A/B toxins were detected by cytotoxicity assay. All suspected colonies of C. perfrin...
