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.
Tirosh-Levy S, Gottlieb Y, Mimoun L, Mazuz ML, Steinman A.Although the main route of transmission of is through tick feeding, transplacental transmission is also possible and may lead to abortion, or to the birth of a sick or carrier foal. The aim of this study was to evaluate the role of as a cause of abortions in Israel and the risk of foals being infected at a young age. Eight aborting mares were serologically evaluated for exposure to via the immunofluorescence antibody test (IFAT) and their aborted fetuses were evaluated using PCR and qPCR. In addition, five mares and their foals (aged 4-6 months) from a highly endemic farm were tested for i...
Sack A, Oladunni FS, Gonchigoo B, Chambers TM, Gray GC. Worldwide, horses play critical roles in recreation, food production, transportation, and as working animals. Horses' roles differ by geographical region and the socioeconomic status of the people, but despite modern advances in transportation, which have in some ways altered humans contact with horses, potential risks for equine zoonotic pathogen transmission to humans occur globally. While previous reports have focused upon individual or groups of equine pathogens, to our knowledge, a systematic review of equine zoonoses has never been performed. Using PRISMA's systematic review guidelines...
Socha W, Sztromwasser P, Dunowska M, Jaklinska B, Rola J.Equine arteritis virus (EAV) is maintained in the horse populations through persistently infected stallions. The aims of the study were to monitor the spread of EAV among Polish Hucul horses, to analyse the variability of circulating EAVs both between- and within-horses, and to identify allelic variants of the serving stallions EqCXCL16 gene that had been previously shown to strongly correlate with long-term EAV persistence in stallions. Serum samples (n = 221) from 62 horses including 46 mares and 16 stallions were collected on routine basis between December 2010 and May 2013 and tested f...
Sunday Idoko I, Tirosh-Levy S, Leszkowicz Mazuz M, Mohammed Adam B, Sikiti Garba B, Wesley Nafarnda D, Steinman A.Equine piroplasmosis (EP) is a tick-borne disease of equids, caused by the two haemoprotozoal parasites: and Nigeria constitutes a major crossroads of animal transport in West Africa and may serve as a factor in EP dissemination in the region. The study aim was to characterize EP parasites in donkeys and horses in northern Nigeria using a molecular approach. Blood was collected from 57 donkeys and 47 horses. EP infection was detected and characterized by polymerase chain reaction (PCR). Twenty five donkeys (43.8%) were infected with , five (8.8%) with three (5.3%) with dual infections. Four...
Gildea S, Lyons P, Lyons R, Gahan J, Garvey M, Cullinane A.Equine influenza (EI) outbreaks occurred among horses on four racing yards (two National Hunt, one Flat, one mixed National Hunt racing/breeding yard) in Ireland within a 4-week period. Objective: To carry out a detailed analysis of racing yards affected in order to identify the source of infection and monitor virus spread among a vaccinated population. Methods: Observational field study. Methods: Epidemiological and vaccination data along with repeat clinical samples were collected from 118 horses on four premises. Results: Failure to implement appropriate biosecurity measures following the i...
Shnaiderman-Torban A, Navon-Venezia S, Dor Z, Paitan Y, Arielly H, Ahmad WA, Kelmer G, Fulde M, Steinman A. We aimed to investigate the prevalence, molecular characteristics and risk factors of extended-spectrum β-lactamase (ESBL)-producing (ESBL-E) shedding in horses. A prospective study included three cohorts: (i) farm horses (13 farms, n = 192); (ii) on hospital admission (n = 168) and; (iii) horses hospitalized for ≥72 h re-sampled from cohort (ii) (n = 86). Enriched rectal swabs were plated, ESBL-production was confirmed (Clinical and Laboratory Standards Institute (CLSI)) and genes were identified (polymerase chain reaction (PCR)). Identification and antibiotic susceptibility were determi...
Soilemetzidou ES, de Bruin E, Eschke K, Azab W, Osterrieder N, Czirják GÁ, Buuveibaatar B, Kaczensky P, Koopmans M, Walzer C, Greenwood AD.The majority of influenza A virus strains are hosted in nature by avian species in the orders of Anseriformes and Charadriformes. A minority of strains have been able to cross species boundaries and establish themselves in novel non-avian hosts. Influenza viruses of horses, donkeys, and mules represent such successful events of avian to mammal influenza virus adaptation. Mongolia has over 3 million domestic horses and is home to two wild equids, the Asiatic wild ass or khulan (Equus hemionus hemionus), and Przewalski's horse (Equus ferus przewalskii). Domestic and wild equids are sympatric acr...
Jenkins E, Backwell AL, Bellaw J, Colpitts J, Liboiron A, McRuer D, Medill S, Parker S, Shury T, Smith M, Tschritter C, Wagner B, Poissant J....Sable Island, Nova Scotia, Canada hosts one of few natural populations of feral horses (Equus caballus) never exposed to anthelmintics. Coproculture revealed cyathostomes, Strongylus equinus, S. edentatus, and S. vulgaris, with S. equinus (unusually) dominating in adult horses and cyathostomes dominating in young horses (<3 years of age). We examined 35 horses found dead in the springs of 2017 and 2018, as well as fecal samples from live horses in spring (n = 45) and summer 2018 (n = 236) using McMaster fecal flotation and Baermann larval sedimentation on fresh samples, and modified Wiscon...
Drozdzewska K, Potocnik E, Schwarz B.Placing a nasogastric tube can be a life-saving act for a horse but is considered an occupational hazard for veterinarians. An online questionnaire was performed to assess and specify potential risks. 123 equine veterinarians completed the survey, and the majority admitted using the mouth to handle the end of the nasogastric tube (sucking or blowing air) and having accidentally swallowed or aspirated stomach content or medications. This can potentially lead to aspiration pneumonia or pneumonitis. Mineral oil seems to be especially dangerous as aspiration may be asymptomatic at the beginning an...
Li F, Wang R, Guo Y, Li N, Feng Y, Xiao L.Limited data are available on infection rates and genetic identity of Enterocytozoon bieneusi and Giardia duodenalis in horses and donkeys. In this study, 865 fecal specimens were collected from donkeys (n = 540) and horses (n = 325) in three provinces and autonomous regions in northern China during 2015-2019. Enterocytozoon bieneusi was detected and genotyped by PCR and sequence analyses of the ribosomal internal transcribed spacer (ITS) and G. duodenalis was detected and genotyped by PCR and sequence analyses of the β-giardin, glutamate dehydrogenase, and triosephosphate isomerase g...
Paillot R.The Food and Agriculture Organization of the United Nations has recently estimated that the world equid population exceeds 110 million (FAOSTAT 2017).[...].
Xie J, Tong P, Zhang A, Song X, Zhang L, Shaya N, Kuang L.In 2015, a novel equine parvovirus, equine parvovirus-cerebrospinal fluid (EqPV-CSF), was identified from cerebrospinal fluid of a horse with neurological signs and lymphocytosis in USA. In our study, an EqPV-CSF-like virus was detected from 15 serum samples of 65 imported thoroughbred horses during custom quarantine in north Xinjiang province, China. Further field investigation in several major horse-producing areas in Xinjiang using specific PCR showed that this virus was detected mainly in thoroughbred horses (39/154 positive) previously imported, not in local breeds (0/127 positive). Phylo...
Tang L, Xiu Y, Yan L, Cui Y, Ma X, Ente M, Zhang Y, Li K, Zhang D.Reintroduction of endangered species to natural habitat is considered as an important tool for conservation. The effect of drug management on captive population of reintroduced species is largely neglected. Decreased drug efficacy could pose a substantial threat to health of animals. More importantly, captive population without proper drug administration could act as transmission medium of resistance nematodes to wild population, making it important to delay the occurrence of drug resistance in captive population. Ivermectin have been used in captive Przewalski's horse () to eradicate intestin...
Duquesne F, Merlin A, Pérez-Cobo I, Sedlák K, Melzer F, Overesch G, Fretin D, Iwaniak W, Breuil MF, Wernery U, Hicks J, Agüero-García M....The accurate identification of Taylorella equigenitalis strains is essential to improve worldwide prevention and control strategies for contagious equine metritis (CEM). This study compared 367 worldwide equine strains using multilocus sequence typing according to the geographical origin, isolation year and equine breed. The strains were divided into 49 sequence types (STs), including 10 described for the first time. Three major and three minor clonal complexes (CCs), and 11 singletons, were identified. The genetic heterogeneity was low (0.13 STs/strain) despite the wide diversity of geographi...
Qi M, Ji X, Zhang Y, Wei Z, Jing B, Zhang L, Lin X, Karim MR, Wang H, Sun M.Giardia duodenalis is a zoonotic intestinal parasite infecting humans and mammals worldwide. In this study, we evaluated the prevalence of G. duodenalis in racehorses in China and genetically characterized it. In total, 621 fecal samples were collected from racehorses at 17 equestrian clubs in 15 cities in China. Forty-eight (7.7%) animals from 11 equestrian clubs were positive for G. duodenalis of assemblages A (n = 10), B (n = 36), and E (n = 2), based on the small subunit ribosomal RNA (SSU rRNA) gene. Statistically significant differences in the prevalence of this parasite were...
Denys M, Léon A, Robert C, Saulnier N, Josson-Schramme A, Legrand L, Wimel L, Maddens S, Pronost S. The growing interest in mesenchymal stromal cells (MSCs) in equine medicine, together with the development of MSC biobanking for allogeneic use, raises concerns about biosafety of such products. MSCs derived from umbilical cord (UC) carry an inherent risk of contamination by environmental conditions and vertical transmission of pathogens from broodmares. There is yet no report in the scientific literature about horses being contaminated by infected MSC products, and no consensus about systematic infectious screening of umbilical cord-derived mesenchymal stromal cells (UC-MSCs) to ensure micro...
Baird J, Tegtmeyer B, Arroyo L, Stang A, Brüggemann Y, Hazlett M, Steinmann E.Theiler's disease was confirmed within a group horses located on a farm in southwestern Ontario during the summer and autumn of 2005. Five sudden deaths occurred between 3 July and 21 August, 2005, none of which were necropsied, however two of the horses showed clinical signs compatible with hepatic encephalopathy prior to death. No horse on the farm had received a biologic product of equine blood origin in the preceding six months. The only biologics used on the property were the administration of killed vaccines for rabies, tetanus and West Nile Virus to all horses 30 days prior to the onset...
Verma A, Beigel B, Smola CC, Kitts-Morgan S, Kish D, Nader P, Morgan J, Roberson J, Christmann U, Gruszynski K, Brandt L, Cho E, Murphy K, Goss R.Leptospirosis is a widespread zoonotic disease that causes reproductive losses and/or hepatorenal failure in a number of animal species. Wild reservoirs of the disease, such as rodents, harbor the causative bacterium, Leptospira spp., in their kidneys and contaminate the environment by excreting infected urine. In this study, we tested small wild mammals, environmental water, and livestock in the Cumberland Gap region of southeastern Appalachia for the presence of pathogenic Leptospira or leptospiral antibodies. Small wild mammals (n = 101) and environmental water samples (n = 89) were screene...
Tarazona AM, Ceballos MC, Broom DM.Excessive human population growth, uncontrolled use of natural resources, including deforestation, mining, wasteful systems, biodiversity reduction by agriculture, and damaging climate change affect the existence of all animals, including humans. This discussion is now urgent and people are rethinking their links with the animals we use for clothing, food, work, companionship, entertainment, and research. The concepts of one health, one welfare, and one biology are discussed as a background to driving global change. Nothing should be exploited without considering the ethics of the action and t...
Vera E, Taddei S, Cavirani S, Schiavi J, Angelone M, Cabassi CS, Schiano E, Quintavalla F.A cross-sectional study was carried out in Bardigiano horses in the Province of Parma, Northern Italy, to assess the seroprevalence of spp. and to investigate risk factors associated with the infection. A representative sample of 134 horses from 43 farms was selected by stratified systematic randomization. Blood sera were examined by MAT for the presence of antibodies against seven serovars. Ninety animals (67.2%; 95% Confidence Interval 63.2-71.1) and 41 farms (95.3%; 95% CI 92.2-98.5%) were found positive to at least one of the serovars. The most frequently detected reactions were against ...
Jones B, Taylor K, Lucas RM, Merritt T, Chicken C, Heller J, Carrick J, Givney R, Durrheim DN.This report describes the challenges encountered in using serological methods to study the historical transmission risk of from horses to humans. In 2017, serology and risk factor questionnaire data from a group of individuals, whose occupations involved close contact with horses, were collected to assess the seroprevalence of antibodies to and identify risk factors associated with previous exposure. 147 participants were enrolled in the study, provided blood samples, and completed a questionnaire. On ELISA testing, antibodies to the Chlamydia genus were detected in samples from 17 participa...
Kachrimanidou M, Tzika E, Filioussis G. is ubiquitous in the environment and is also considered as a bacterium of great importance in diarrhea-associated disease for humans and different animal species. Food animals and household pets are frequently found positive for toxigenic without exposing clinical signs of infection. Humans and animals share common ribotypes (RTs) suggesting potential zoonotic transmission. However, the role of animals for the development of human infection due to remains unclear. One major public health issue is the existence of asymptomatic animals that carry and shed the bacterium to the environment, an...
Egbe-Nwiyi TN, Paul BT, Cornelius AC.This study aimed to investigate the prevalence and intensity of nematode infection among slaughtered donkeys in Kaltungo, Nigeria. Methods: A total of 72 fecal samples were examined by salt flotation and the modified McMaster fecal egg count technique to morphologically identify nematodes eggs and determine their egg per gram (EPG) outputs. Results: Out of a total of 72 (100%) donkeys sampled, 36 (50%) tested positive, but the prevalence of nematodes was independent of the age, sex, and breed of donkeys (p>0.05). Among the four species of nematodes identified in single and mixed infections,...
Pronost S, Fortier C, Marcillaud-Pitel C, Tapprest J, Foursin M, Saunier B, Pitel PH, Paillot R, Hue ES.(1) Background: Equine hepacivirus (EqHV), also referred to as non-primate hepacivirus (NPHV), infects horses-and dogs in some instances-and is closely related to hepatitis C virus (HCV) that has infected up to 3% of the world's human population, causing an epidemic of liver cirrhosis and cancer. EqHV also chronically infects the liver of horses, but does not appear to cause serious liver damages. Previous studies have been looking to identify route(s) of EqHV transmission to and between horses. (2) Methods: In this retrospective study, we sought to evaluate the prevalence of vertical transmis...
Rui P, Zhao F, Yan S, Wang C, Fu Q, Hao J, Zhou X, Zhong H, Tang M, Hui W, Li W, Shi D, Ma Z, Song T.Hepatitis E virus (HEV) is the causative agent of acute self-limiting hepatitis in humans in developing countries. Hepatitis E virus RNA was first detected in donkeys in Spain, but little is known about the possible presence of HEV in donkeys in China. Objective: To investigate the prevalence of HEV in donkeys in northern China. Methods: Investigation of the prevalence of HEV in donkeys using serological, molecular and phylogenetic approaches. Methods: A total of 401 donkey serum specimens were tested for serological and molecular detection of HEV via enzyme-linked immunosorbent assay and quan...
Oladunni FS, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) is one of the most important and prevalent viral pathogens of horses and a major threat to the equine industry throughout most of the world. EHV-1 primarily causes respiratory disease but viral spread to distant organs enables the development of more severe sequelae; abortion and neurologic disease. The virus can also undergo latency during which viral genes are minimally expressed, and reactivate to produce lytic infection at any time. Recently, there has been a trend of increasing numbers of outbreaks of a devastating form of EHV-1, equine herpesviral myeloenceph...
Albert E, Biksi I, Német Z, Csuka E, Kelemen B, Morvay F, Bakos Z, Bodó G, Tóth B, Collaud A, Rossano A, Perreten V.Between July 2011 and May 2016, a total of 40 Staphylococcus aureus strains originating from 36 horses were confirmed as methicillin resistant (methicillin-resistant Staphylococcus aureus [MRSA]) in a university equine clinic. An additional 10 MRSA strains from 36 samples of clinic workers were obtained in October 2017. The first equine isolate represented the sequence type ST398, spa-type t011, and SCCmec IV. This isolate was resistant to a wide spectrum of antimicrobial agents. MRSA strains with the same genotype and with very similar resistance profiles were isolated on 21 more occasions fr...
Pronost S, Fortier C, Marcillaud-Pitel C, Tapprest J, Foursin M, Saunier B, Pitel PH, Paillot R, Hue ES.(1) Background: Equine hepacivirus (EqHV), also referred to as non-primate hepacivirus (NPHV), infects horses-and dogs in some instances-and is closely related to hepatitis C virus (HCV) that has infected up to 3% of the world's human population, causing an epidemic of liver cirrhosis and cancer. EqHV also chronically infects the liver of horses, but does not appear to cause serious liver damages. Previous studies have been looking to identify route(s) of EqHV transmission to and between horses. (2) Methods: In this retrospective study, we sought to evaluate the prevalence of vertical transmis...
Yamanaka T, Nemoto M, Bannai H, Tsujimura K, Kondo T, Matsumura T, Muranaka M, Ueno T, Kinoshita Y, Niwa H, Hidari KI, Suzuki T.Since equine influenza A virus (H3N8) was transmitted to dogs in the United States in 2004, the causative virus, which is called canine influenza A virus (CIV), has become widespread in dogs. To date, it has remained unclear whether or not CIV-infected dogs could transmit CIV to horses. To address this, we tested whether or not close contact between horses and dogs experimentally infected with CIV would result in its interspecies transmission. Methods: Three pairs of animals consisting of a dog inoculated with CIV (10(8.3) egg infectious dose 50/dog) and a healthy horse were kept together in i...
Alanazi AD, Said AE, Morin-Adeline V, Alyousif MS, Slapeta J.Equine piroplasmosis is the most important tick-borne disease of horses. Regulations on movement of horses into disease-free countries are in place to preserve international trade. Introduction of infectious disease, such as equine piroplasmosis, into non-endemic countries remains a substantial risk owing to the wide-spread distribution of vectors. Identification and restriction of movement of Theileria equi persistently infected horses is an integral part of control strategies, because persistently infected horses with low parasitaemia are an important reservoir. We used real-time PCR for dia...
Guimarães AM, Lima JD, Ribeiro MF.The development of Babesia equi in salivary glands of adult female Boophilus microplus was observed under a light microscope using semithin sections stained with toluidine blue. Engorged nymphs were obtained from splenectomized foals experimentally infected with B. equi. As adults, they were then fed on rabbits for 5 days and the salivary glands of manually collected individuals were removed at intervals of 24 h. Sporozoites were found in type III granular acini cells between the 2nd and 5th days following feeding on the rabbits. Sporoblasts and sporozoites were observed in the same or adjacen...
Sugiura T, Shimada K.A sero-epizootiological survey was conducted for Japanese encephalitis virus (JEV) and Getah virus (GeV) at 10 to 20 regional horse race tracks from 1991 to 1997 in Japan. It was observed that geometrical mean (GM) antibody titer to JEV and GeV was 10 to 50 times higher than others at several race courses (RCs) almost every year. Of them, several race horses showing high antibody titer, which were suggested to be infected with the virus, were also observed in this survey. These data suggested that the viruses have spread among race horses almost every year in Japan, although, fortunately, no h...
Pusterla N, Barnum S, Young A, Mendonsa E, Lee S, Hankin S, Brittner S, Finno CJ.While the main goal in the management of an EHM outbreak focuses on identifying early clinical disease in order to physically separate infected horses, little effort is placed towards monitoring healthy horses. The assumption that EHV-1 shedding parallels clinical disease is erroneous, as subclinical shedders have been shown to be actively involved in viral spread. In an attempt to document the frequency of EHV-1 shedders and their impact on environmental contamination, we collected nasal swabs from 231 healthy horses and 203 environmental samples for the testing of EHV-1 by qPCR. Six horses a...
Gómez-Sanz E, Simón C, Ortega C, Gómez P, Lozano C, Zarazaga M, Torres C.Eight coagulase-positive staphylococci from equines with different pathologies obtained between 2005 and 2011 were investigated. Isolates were characterized by different molecular techniques (spa-, agr-, MLST), and clonal relatedness of strains was investigated by ApaI and SmaI PFGE. Anti-microbial resistance and virulence profiles were determined. Six isolates were identified as Staphylococcus aureus, and two as Staphylococcus pseudintermedius. Of these, four isolates were methicillin-resistant S. aureus (MRSA) ST398 and one S. pseudintermedius was mecA positive and typed as ST68. One MRSA ...
Onder Z, Yildirim A, Pekmezci D, Duzlu O, Pekmezci GZ, Ciloglu A, Simsek E, Kokcu ND, Yetismis G, Ercan N, Inci A.A total of 1340 fresh fecal samples from farm and pet animals in Central Anatolia and the Middle Black Sea Region of Turkey were investigated using a PCR assay targeting the SSU rRNA of Blastocystis sp. An overall Blastocystis sp. prevalence of 19.4% (183/940) was found in farm animals, including cattle, sheep, water buffaloes, and chickens. Fecal samples of dogs, cats, and horses were negative. The highest prevalence of Blastocystis sp. was found in sheep (38.2%) among the farm animals. The SSU rRNA sequence analysis revealed two animal-specific subtypes, including ST10 in cattle and sheep an...
Kay BH, Pollitt CC, Fanning ID, Hall RA.Eleven weanling horses were inoculated with Murray Valley encephalitis and Ross River viruses either by intravenous injection or by the bite of Culex annulirostris or Aedes vigilax mosquitoes infected orally. Five of the 11 horses circulated trace amounts of MVE virus for 1 to 5d and they infected 7/408 Cx annulirostris which subsequently fed on them. Haemagglutination-inhibiting antibody persisted at detectable levels for the 24-week observation period. With Ross River virus, only one of 11 horses inoculated developed a viraemia detectable by inoculation of suckling mice but 5 horses containe...
Sudia WD, Fernandez L, Newhouse VF, Sanz R, Calisher CH.Virus vector studies were conducted in the States of Durango, Chihuahua, and Tamaulipas, Mexico, in June and July 1972. Apparently only a low level of Venzuelan equine encephalitis (VEE) virus transmission to equines occured at the time of the study, and the infection was restricted to areas which had not experienced overt activity during the preceding year. The low level of infection was associated with a scarcity of mosquitoes. The IB (epidemic) strain of VEE virus was isolated from two pools of Anopheles pseudopunctipennis (Theo.) and the blood of one symptomatic equine. The low mosquito po...
Horak IG, Heyne H, Halajian A, Booysen S, Smit WJ.The aim of the study was to determine the species spectrum of ixodid ticks that infest horses and donkeys in South Africa and to identify those species that act as vectors of disease to domestic livestock. Ticks were collected opportunistically from 391 horses countrywide by their owners or grooms, or by veterinary students and staff at the Faculty of Veterinary Science, University of Pretoria. Ticks were also collected from 76 donkeys in Limpopo Province, 2 in Gauteng Province and 1 in North West province. All the ticks were identified by means of a stereoscopic microscope. Horses were infest...
Lillini E, Macrì G, Proietti G, Scarpulla M.Ixodes ricinus (I. ricinus) is one of the vectors of Anaplasma phagocytophilum (A. phagocytophilum) in Europe, in which rates of infection range from 1.9% to 34%. In 1998, human granulocytic ehrlichiosis-like (HGE-like) Ehrlichia DNA was detected in Italy, by PCR technique in one I. ricinus nymph out of 55 ticks that were examined. In 1996, 6.3% of 310 human sera in high-risk subjects from Italy were found positive for antibodies to Ehrlichia phagocytophila (E. phagocytophila). In the same year, the authors reported the first case of equine granulocytic ehrlichiosis. In 1997, only 2 out of 563...
Baird JD, Arroyo LG.In the summer of 1924 Dr. Frank W. Schofield conducted investigations into an endemic disease of horses in the Kent and Essex counties of Ontario. According to farmers in these counties the disease had existed in this region for at least 50 years previously. The clinical, pathological, histopathological, and epidemiological findings outlined in Schofield's detailed report strongly suggest that this endemic disease was what was designated in 1979 as "Potomac horse fever" (PHF). This assumption is further substantiated by transmission experiments involving horses and laboratory animals that were...
Verheyen K, Newton JR, Talbot NC, de Brauwere MN, Chanter N.Three protracted outbreaks of strangles were investigated using endoscopic examination and a total of 14 asymptomatic carriers of Streptococcus equi were identified of which 13 showed evidence of carriage in the guttural pouch. Treatment was initiated to eliminate S. equi colonisation since these animals posed an infectious risk to susceptible horses. Two further horses were referred to us with severe guttural pouch pathology and from which S. equi was cultured, and treatment of these cases is also described. Treatment in the first instance was directed towards removal of gross guttural pouch ...
Berthoud H, Frey J, Kuhnert P.Actinobacillus equuli, a member of the family Pasteurellaceae is the etiologic agent of a frequently lethal septicemia in neonatal foals as well as other more chronic diseases like arthritis, pleuritis, pneumonia or peritonitis. It may also be isolated from the oral cavity of healthy horses. Hemolytic isolates of A. equuli are known but so far no virulence determinants have been described for this bacterial species. By screening hemolytic A. equuli strains with specific gene probes, a hemolysin, designated Aqx (A. equuli RTX (repeats in the structural toxin)) was identified. This hemolysin was...
Duggan JM, Coates DM, Ulaeto DO.Venezuelan equine encephalomyelitis (VEE) virus is an important human and veterinary pathogen of Central and South America. The virus can cause widespread epidemics, affecting hundreds of thousands of horses, and thousands of humans. Detection of the virus early in infection and in mosquito populations may allow epidemics to be predicted such that suitable prophylaxis, such as vaccination, can be used to reduce disease severity and transmission. The sensitivity and specificity of current immunoassays, based on conventional monoclonal and polyclonal antibodies, needs to be improved for the diag...
Muscatello G, Gilkerson JR, Browning GF.Virulent Rhodococcus equi causes pyogranulomatous bronchopneumonia in foals. The route of infection of foals has been considered to be inhalation of aerosolized bacteria from soil that is contaminated with equine feces. Thus, disease caused by R. equi has been regarded as an opportunistic infection of environmental origin and not a contagious disease. In this study, we report the exhalation of virulent R. equi from the respiratory tract of naturally infected foals. A handheld air-monitoring system was used to recover virulent R. equi from the exhaled breath of foals, and the concentration of v...
Ghosh S, Taniguchi K, Aida S, Ganesh B, Kobayashi N.Equine group A rotaviruses (RVA) are a major cause of severe diarrhea in foals. The whole genomes of only six common and three unusual equine RVA strains have been analyzed so far. To date, there are no reports on whole genomic analyses of equine RVAs from Asian countries. We report here the whole genomic analyses of three common (strains RVA/Horse-tc/JPN/BI/1981/G3P[12], RVA/Horse-tc/JPN/HH-22/1989/G3P[12] and RVA/Horse-tc/JPN/CH-3/1987/G14P[12]) and an unusual (RVA/Horse-tc/JPN/OH-4/1982/G6P[5]) equine RVA strains isolated from diarrheic foals in Japan. Strains BI, HH-22 and CH-3 shared a la...
Auty H, Mundy A, Fyumagwa RD, Picozzi K, Welburn S, Hoare R.Horses kept for recreational riding purposes by a wildlife tourism company in a heavily tsetse fly-infested region of north-western Tanzania were systematically monitored to investigate the occurrence, presentation and management of tsetse-transmitted trypanosomosis. During a 23-month period, 18 clinical cases were diagnosed (Trypanosoma brucei or Trypanosoma congolense were identified) and treated and trypanosomes were implicated of involvement in four deaths. Pyrexia consistently aided early detection (17 cases). Ataxia, weight loss and anaemia were seen in chronic cases and conferred a poor...
Myers R, Cembran A, Fernandez-Funez P.Prion diseases are a group of neurodegenerative diseases endemic in humans and several ruminants caused by the misfolding of native prion protein (PrP) into pathological conformations. Experimental work and the mad-cow epidemic of the 1980s exposed a wide spectrum of animal susceptibility to prion diseases, including a few highly resistant animals: horses, rabbits, pigs, and dogs/canids. The variable susceptibility to disease offers a unique opportunity to uncover the mechanisms governing PrP misfolding, neurotoxicity, and transmission. Previous work indicates that PrP-intrinsic differences (s...
de Oliveira PB, Harvey TV, Fehlberg HF, Rocha JM, Martins TF, da Acosta ICL, Labruna MB, Faccini JLH, Albuquerque GR.Tick-borne spotted fever in Brazil is known to be caused by two agents, Rickettsia rickettsii and Rickettsia parkeri. Nothing was known about these agents in one area of the Atlantic rainforest biome of Bahia state, where during March to June 2016, 356 rural dogs and 69 horses were sampled and their sera were processed through indirect immunofluorescence assay against antigens of R. rickettsii, R. parkeri, Rickettsia amblyommatis and Rickettsia bellii. Ticks collected from these dogs and horses were molecularly tested for the presence of rickettsial DNA. Overall, 16.4% (58/356) dogs and 24.6% ...
Lawton KOY, Arthur RM, Moeller BC, Barnum S, Pusterla N.More and more studies are reporting on the natural transmission of SARS-CoV-2 between humans with COVID-19 and their companion animals (dogs and cats). While horses are apparently susceptible to SARS-CoV-2 infection based on the homology between the human and the equine ACE-2 receptor, no clinical or subclinical infection has yet been reported in the equine species. To investigate the possible clinical role of SARS-CoV-2 in equids, nasal secretions from 667 horses with acute onset of fever and respiratory signs were tested for the presence of SARS-CoV-2 by qPCR. The samples were collected from...
Fall M, Fall AG, Seck MT, Bouyer J, Diarra M, Balenghien T, Garros C, Bakhoum MT, Faye O, Baldet T, Gimonneau G.Culicoides biting midges (Diptera: Ceratopogonidae) are important vectors of arboviruses in Africa. Culicoides oxystoma has been recently recorded in the Niayes region of Senegal (West Africa) and its high abundance on horses suggests a potential implication in the transmission of the African horse sickness virus in this region. This species is also suspected to transmit bluetongue virus to imported breeds of sheep. Little information is available on the biology and ecology of Culicoides in Africa. Therefore, understanding the circadian host-seeking activity of this putative vector is of prima...
Hamond C, Pinna A, Martins G, Lilenbaum W.Leptospirosis is a zoonotic disease of global importance and has a worldwide distribution. This infection displays clear seasonal nature in some regions of the tropics, where the rainy season is marked by high temperatures. Household and wild animals carry leptospires and contribute to their dissemination in nature. Transmission mainly occurs by contact with water contaminated with the urine of infected animals, and consequently, it is quite widespread especially in times of rain, since many areas are subject to flooding and have poor sanitation. Serological tests demonstrate that Leptospira s...
Badenhorst M, Page P, Ganswindt A, Laver P, Guthrie A, Schulman M.The prevalence of equine herpesvirus types-1 and -4 (EHV-1 and -4) in South African Thoroughbreds at auction sales is currently undefined. Commingling of young Thoroughbreds from various populations together with physiological stress related to their transport and confinement at a sales complex, may be associated with shedding and transmission of EHV-1 and -4. This prospective cohort study sampled 90 young Thoroughbreds consigned from eight farms, originating from three provinces representative of the South African Thoroughbred breeding demographic to a sales complex. Nasal swabs for quantitat...
Kumar K, Arshad SS, Selvarajah GT, Abu J, Toung OP, Abba Y, Yasmin AR, Bande F, Sharma R, Ong BL.Japanese encephalitis (JE) is a vector-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). It causes encephalitis in human and horses, and may lead to reproductive failure in sows. The first human encephalitis case in Malaya (now Malaysia) was reported during World War II in a British prison in 1942. Later, encephalitis was observed among race horses in Singapore. In 1951, the first JEV was isolated from the brain of an encephalitis patient. The true storyline of JE exposure among humans and animals has not been documented in Malaysia. In some places such as Sarawak, JEV ha...
Misra KK, Roy S, Choudhury A.Trypanosoma (Trypanozoon) evansi is a causative agent of the dreadful mammalian disease trypanosomiasis or 'Surra' and carried as a latent parasite in domestic cattle but occasionally proves fatal when transmitted to horses and camel. Sporadic outbreak of 'Surra' to different animals (beside their natural hosts) reminds that T. evansi may be zoonotic, as their close relative cause sleeping sickness to human being. This haemoflagellate is mechanically transmitted by horse fly and its effect on different host varies depending on certain factors including the effectiveness of transmission by mech...
Shepard JJ, Andreadis TG, Thomas MC, Molaei G.Eastern equine encephalitis virus (EEEV) is a highly pathogenic mosquito-borne arbovirus, with active transmission foci in freshwater hardwood swamps in eastern North America, where enzootic transmission is maintained between the ornithophilic mosquito, Culiseta melanura, and wild passerine birds. The role of other locally abundant mosquito species in virus transmission and their associations with vertebrate hosts as sources of blood meals within these foci are largely unknown but are of importance in clarifying the dynamics of enzootic and epidemic/epizootic transmission. Blood-engorged mosqu...
Johansen CA, Williams SH, Melville LF, Nicholson J, Hall RA, Bielefeldt-Ohmann H, Prow NA, Chidlow GR, Wong S, Sinha R, Williams DT, Lipkin WI....In northern Western Australia in 2011 and 2012, surveillance detected a novel arbovirus in mosquitoes. Genetic and phenotypic analyses confirmed that the new flavivirus, named Fitzroy River virus, is related to Sepik virus and Wesselsbron virus, in the yellow fever virus group. Most (81%) isolates came from Aedes normanensis mosquitoes, providing circumstantial evidence of the probable vector. In cell culture, Fitzroy River virus replicated in mosquito (C6/36), mammalian (Vero, PSEK, and BSR), and avian (DF-1) cells. It also infected intraperitoneally inoculated weanling mice and caused mild c...
