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.
Findlay GM, Maccallum FO.(1) Among 3,100 persons immunized against yellow fever with virus and immune serum over a period of five years, 89 cases of jaundice have been traced.(2) The symptoms are those of a hepatitis and closely resemble those produced by common infective hepatic jaundice, cases of which have frequently been noted as occurring in the same areas.(3) The average period between the time of inoculation and the development of hepatitis is between two and three months.(4) Attention is directed to the occurrence of hepatitis in horses, usually two to three months after immunization against the viruses of hor...
Tenbroeck C, Hurst EW, Traub E.Equine encephalomyelitis of the eastern type is a disease of the late summer and fall and cases are found in greatest numbers near salt marshes. The epidemiological findings are against its transmission by contact and favor the view that it is insect borne. Although virus can be demonstrated in the blood of infected horses it is present for a relatively short time, and the possibility that the disease is not primarily an infection of horses but that it is transmitted to them from another host is considered.
Woods AC, Chesney AM.A filterable agent has been obtained from the humors and tissues of the eyes of horses suffering from active periodic ophthalmia. The intra-vitreous injection of this filtrate produced in normal horses the same clinical and pathological picture observed in the natural disease. This filtrate injected into rabbits produced a different clinical picture, but the essential pathological lesions closely resembled those found in horses. After passage of the filterable agent through six generations of rabbits, it again produced the clinical and pathological picture of the natural disease when injected ...
Shams N, Jaydari A, Khademi P, Eydi J, Sgroi G.Due to the abundance of ticks on open grassy surfaces, racetracks may represent ideal scenarios for tick-borne pathogens. Therefore, in 2024/2025 Turkmen horses (Akhal-Teke breed) and ticks collected by dragging in paddocks of Iran were screened for Anaplasmataceae using Sanger sequencing on 16S rRNA, TRP36 and dsb genes. Amongst 200 horses, 11 (5.5%) tested positive without signs/symptoms, being 8 (4%) for Ehrlichia canis and 3 (1.5%) for Anaplasma ovis; no difference in prevalence was found by gender and age (p>0.05). All ticks were identified as Hyalomma asiaticum and Haemaphysalis sulca...
K-Jánosi K, Sztojka A, Kis IE, Biksi I, Bakos Z, Kaszab E, Mag T, Albert E.In 2024, a highly fatal outbreak of equine salmonellosis occurred in a Hungarian equine referral hospital, resulting in the death or euthanasia of four out of five affected horses. () subsp. serovar Typhimurium was identified as the primary causative agent from equine faecal, reflux, and post-mortem intestinal content samples, while one case involved Coeln. Extensive environmental sampling during the outbreak also yielded multiple serovars. Whole-genome sequencing revealed a high degree of genetic relatedness among the Typhimurium isolates, confirming nosocomial transmission. The source ...
West Nile virus (WNV) circulates endemically in Romania, yet prevention of WNV infection in horses largely depends on owner-driven decisions that require accurate risk perception and veterinary guidance. A cross-sectional online survey was carried out between May and November 2025 to evaluate the knowledge, attitudes, and preventive practices (KAP) regarding WNV among 227 horse owners from various Romanian regions. In total, 67.4% of respondents had previously heard of WNV. The main transmission route was correctly identified as mosquito bites by 49.8% of participants, while 32.2% answered "do...
Firdausy LW, Fikri F, Wicaksono AP, Maslamama ST, Purnama MTE.Equine viral arteritis (EVA) is a globally widespread infectious disease affecting equids, with significant consequences for reproductive efficiency and the regulation of international equine trade. Nevertheless, despite the accumulation of numerous region-specific investigations, an integrated synthesis of global seroprevalence estimates and overarching epidemiological patterns remains insufficiently developed. Objective: To calculate the pooled global seroprevalence of EVA and to explore sources of epidemiological heterogeneity. Methods: A systematic review and meta-analysis were undertaken ...
Ehizibolo DO, Oyekan O, Mkpuma N, Haliru H, Garba I, Turaki IZ, Williams EE, Danmarwa A, Mohammed A, Muhammad MA, Abubakar M, Brown C, Faburay B.Rift Valley Fever (RVF) is a neglected vector-borne zoonotic disease of significant veterinary and public health concern in Sub-Saharan Africa. This study investigated the seroprevalence of Rift Valley Fever Virus (RVFV) exposure and associated risk factors among camels and horses marketed in northern Nigeria. A total of 1117 animals were sampled, comprising camels (812) and horses (305), across three major livestock markets (Maigatari, Maiduguri, and Illela). The overall seroprevalence was 18.8% (95% CI: 16.6-21.2%), with a striking six-fold disparity: camels showed a prevalence of 24.4% (95%...
Jiang Z, Merits A, Qin Y, Xing G, Zhang L, Chen J, Wang N, Varjak M, Zhai X, Li D, Song W, Su S.Alphaviruses are important arthropod-transmitted pathogens of humans and livestock. Getah virus (GETV) is an arthritogenic alphavirus that causes disease in horses and piglets; it also poses a potential threat to humans. A live attenuated vaccine candidate named GETV-3ΔS2-CM1, harbouring a deletion in nonstructural protein 3 and substitutions in the capsid protein, is genetically stable and exhibits robust immunogenicity. It was shown to confer passive protection to piglets born to immunized sows. In mice, a single dose of GETV-3ΔS2-CM1 protected against infection with different strains of G...
Noh H, Cho HU, Kim SH.The genus is widely distributed and includes species with ecological and biotechnological importance. In this study, morphological and phylogenetic analyses of the ITS and LSU rDNA sequences revealed two novel species, sp. nov. and sp. nov., as well as one previously unrecorded species in Korea, , from horse dung collected in Seopjikoji, Jeju Island, Republic of Korea. sp. nov. is unique in producing conidia from conidiomata instead of teleomorphic structures, a feature not observed in any other known species of the genus. sp. nov. is morphologically distinguished by the absence of a nec...
Delling C, Helm C, Heinze P, Friedman M, Böttcher D.While the principle definitive host of the zoonotic cestode in Europe is the red fox, several rodent species act as main intermediate hosts. Among others, e.g., humans, dogs, and pigs, also horses have been described to act as aberrant hosts in highly endemic regions. Here, a case of an infection in a kulan () is described. The five years old kulan from a zoo in Slovakia was transported to an animal park in Germany. The animal had to be euthanized within a few weeks after the import due to its poor general state of health. The pathological examination revealed a nodular mass in the liver as ...
Stokes JE, Labuschagne K, Fèvre EM, Baylis M.In recent decades there has been a huge increase in the export of cut flowers from countries in Africa and elsewhere to European flower markets, with the vast majority first entering the Netherlands for local use or for export. Coincidentally, three significant livestock disease outbreaks caused by viruses associated with Africa or other tropical regions were first detected in the Netherlands (bluetongue virus serotype 8 (BTV-8), 2006, and BTV-3, 2023) and in western Germany about 200 km from the Netherlands border (Schmallenberg virus, SBV, 2011). This study aimed to determine whether Culic...
Ma W, Gao L, Wu X, Zhong L, Huang X, Yang R, Wu H, Zhu L, Ma W, Peng L, Li B, Song J, Luo S, Bao F, Liu A.Both Borrelia burgdorferi (Bb) and Anaplasma phagocytophilum (Ap) can infect humans and animals through tick-borne transmission, resulting in zoonosis. Under certain conditions, human infection can lead to Lyme disease (LD) and human granulocytosis (HGA), whereas infection in animals can cause various acute and non-specific symptoms. The combination of Bb and Ap has been reported to increase the disease severity in infected animals. In this systematic review and meta-analysis, we investigated the global diversity of Bb and Ap coinfection in animals and their prevalence and distribution regardi...
Kozak S, Merda D, Duquesne F, Breuil MF, Mawhinney I, Petry S.In 2018, a T. asinigenitalis strain (MCE663) was isolated in a Persian onager tested for contagious equine metritis (CEM) in a United Kingdom (UK) zoo. This bacterium had never been reported in the UK and Multilocus Sequence Typing described a new atypically divergent ST (ST60). Although the causative agent of CEM is the bacterium Taylorella equigenitalis, a first natural outbreak of endometritis caused by T. asinigenitalis ST70 was reported in 2019, putting its pathogenic potential into question. In this context, we aimed to further sequence the T. asinigenitalis MCE663 genome and characteriz...
Bland J, McGowan C, Bush E, Lloyd V.Zoonotic diseases have major impacts on human and animal health, as well as being ecologically significant. Lyme Borreliosis or Lyme disease, caused by infection by pathogenic members of the Borrelia genus, is among these zoonotic diseases. Serology is one of the most accessible means for indirect surveillance of pathogen presence by monitoring the presence, abundance, and type of immune response to the pathogen or pathogen-associated epitopes. Serological surveillance of wild animals is important as wild animals are the primary reservoirs of many zoonotic diseases. Similarly, serological sur...
Rouby S, Ewies S.Bovine papillomatosis is an infectious viral disease of cattle characterized by development of benign cutaneous warts. The present study describes bovine papillomavirus infection in cattle on clinco-pathological and molecular bases and compares the identified strains with the previously characterized papillomavirus isolates in Egypt either of bovine or equine origin. Out of sixty examined cattle, skin lesions were collected from eleven clinically diseased cattle exhibiting typical papillomatosis clinical signs and subjected to histopathological and molecular identification. Histological sectio...
Fan X, Li W, Oros J, Plung JS, Plante JA, Basu H, Nagappan-Chettiar S, Boeckers JM, Tjang LV, Mann CJ, Brusic V, Buck TK, Varnum H, Yang P....After decades of inactivity throughout the Americas, western equine encephalitis virus (WEEV) recently re-emerged in South America, causing a large-scale outbreak in humans and horses. WEEV binds protocadherin 10 (PCDH10) as a receptor; however, nonpathogenic strains no longer bind human or equine PCDH10 but retain the ability to bind avian receptors. Highly virulent WEEV strains can also bind the very low-density lipoprotein receptor (VLDLR) and apolipoprotein E receptor 2 (ApoER2) as alternative receptors. Here, by determining cryo-electron microscopy structures of WEEV strains isolated from...
Rosa-Xavier IG, Pinter A, Giuffrida R, Biondo AW, Kmetiuk LB, Santarém VA.(1) Background: Brazilian spotted fever (BSF) is a tick-borne disease that has occurred in several Brazilian regions, caused by spp. bacteria and mainly transmitted by ticks. Despite the high BSF lethality in several Brazilian endemic areas, predictors and associated risk factors remain to be fully established. Accordingly, the retrospective study herein aimed to assess BSF cases and associated factors in an endemic area of western São Paulo state. (2) Methods: Notified cases identified by the System for Epidemiological Surveillance of São Paulo (CVE), from January 2007 to December 2021, w...
Oshida J, Ito H, Ubukata K, Takata M, Ohkusu K, Ohba S, Saida A, Nakamura S, Kobayashi D.Streptococcus suis is a Gram-positive zoonotic pathogen primarily associated with pigs, but its potential transmission from other animals remains unclear. We report a case of S. suis serotype 2 meningitis in a 56-year-old Filipino stable worker with no known contact with pigs but a history of direct exposure to horses. He presented with fever and persistent headache following a head injury sustained one month prior. Cerebrospinal fluid (CSF) analysis revealed bacterial meningitis, and blood and CSF cultures identified S. suis serotype 2. Despite appropriate antibiotic therapy, the patient deve...
Zu H, Sun R, Li J, Guo X, Wang M, Guo W, Wang X.Strangles, a highly contagious disease caused by subspecies (), significantly impacts horse populations worldwide, with Iceland as the only exception. This disease poses serious threats to equine health and results in considerable economic losses. Consequently, the accurate, sensitive, and rapid detection of from clinical samples is essential for early warning and effective disease management. This study introduces a novel detection method that integrates recombinase-aided amplification (RAA) with CRISPR/Cas12a technologies. We specifically designed RAA primers and CRISPR RNA to target the ...
Bauswein M, Arnold L, Springer DN, Redlberger-Fritz M.Borna disease virus 1 (BoDV-1) is a zoonotic virus with a recently confirmed potential to cause rare but severe cases of encephalitis in humans. While the bicolored white-toothed shrew (Crocidura leucodon), which represents the reservoir, is widely distributed over eastern, central, and southern Europe as well as south-west Asia, human infections have so far only been reported from Germany. As infections in sentinels such as horses indicate the endemic circulation of the virus also in circumscribed regions of neighboring countries (Austria, Liechtenstein, Switzerland), we initiated a retrospec...
Martin G, Tyson GH, Guag J, Strain E, Ceric O.Klebsiella spp. is an important human and animal pathogen, and it is commonly found with resistance to clinically important antimicrobials worldwide. The main goals of this study were to determine the prevalence of antimicrobial resistance genes in our study population and to assess the relatedness between Klebsiella spp. isolated from humans and animals. Isolates were collected in 2019 and 2020 from various animal hosts that presented to veterinary hospitals in the U.S. that participate in the FDA's Center for Veterinary Medicine Veterinary Laboratory Investigation and Response Network's anti...
Yuan Y, Hao Y, Peng C, Zhang D, Ma W, Xiao P, Li N.Getah virus (GETV) is a member of the of the . It is a single-stranded positive-RNA virus that is mainly transmitted by mosquitoes. In recent years, the spread of GETV has become increasingly serious, causing serious losses to the animal economy and posing a potential threat to public health. GETV infected animals extend from traditional domestic animals such as horses and pigs to cattle, foxes and other animals. Especially in China, the virus has been detected in many provinces in recent years. In addition, GETV-specific antibodies were detected in healthy humans. However, the threat posed b...
Gomes-Gonçalves S, Mesquita JR, Ruano ZM, Barradas PF.Coxiella burnetii is a bacterium that causes coxiellosis in animals and Q fever in humans. While ruminants are the main reservoirs, the role of ticks in their transmission is still uncertain. This study looked for C. burnetii in ticks collected from two autochthonous breeds in Portugal: Churra Galega Mirandesa sheep and Garrano horses. A total of 555 ticks were tested, including 100 Rhipicephalus sanguineus sensu (s.) stricto (s.) from sheep and 455 Rhipicephalus bursa from horses. Coxiella burnetii was found in 7 % of R. sanguineus s.s., but not in R. bursa. Phylogenetic analysis confirmed th...
Singh B, Sulaiman ZI, Raynor EM.We present a rare case of subspecies zooepidemicus (SEZ) bacteremia in a 73-year-old male with a history of Parkinson's disease, pulmonary embolism, and recent left knee total arthroplasty who developed fever and sepsis complicated by septic arthritis of a prosthetic knee and deep vein thrombosis (DVT). Blood cultures grew in four out of four bottles, and history revealed frequent horse exposure, suggesting zoonotic transmission with hematogenous seeding of the prosthetic joint. The diagnosis was further challenged by systemic computed tomography (CT) abnormalities and the concurrent DVT, wh...
Jochumsen S, Kk Vishram-Nielsen J, Pump BB, Seibæk MB, Bruun NE.Infective endocarditis (IE) is a dreaded disease with a high mortality rate. In Denmark, IE is most often caused by or species. We present a rare case of a 50-year-old woman with a history of a dual-chamber pacemaker due to third-degree atrioventricular block and a mechanical mitral valve inserted due to mitral stenosis. The patient was admitted to the hospital after she was found lying on the floor in her home. The patient was diagnosed with subspecies () prosthetic heart valve IE, which was complicated with meningitis, myocardial infarction, and an increasing vegetation load despite antib...
Songsungthong W, Pornthanakasem W, Leartsakulpanich U, Srijuntongsiri G.The ability to accurately and rapidly identify causative agents of infectious diseases facilitates precise treatment, improves clinical outcomes, and augments epidemiology studies. For many veterinary and zoonotic pathogens, however, simple molecular tests for species identification are not available. causes severe diseases, such as sleepy foal disease, septicemia, and meningitis in horses and pigs. can also cause severe diseases in humans bitten by infected animals. Existing identification methods are biochemical tests, 16S rRNA gene amplification followed by DNA sequencing, and MALDI-TOF ...
Buyens ARM, van Staden V, Theron J.African horse sickness, caused by African horse sickness virus (AHSV) that is transmitted by midges of the Culicoides genus, leads to rapid mortality among horses. Proteases in the saliva of Culicoides midges cleave the VP2 outer capsid protein, resulting in infectious sub-virus particles that have increased infectivity for the Culicoides vector insect and Culicoides-derived cells (KC cells). The AHSV VP7 protein has an arginine-glycine-aspartate (RGD) motif, but the functional relevance of this protein and motif in facilitating binding to insect cells is unknown. To investigate, core-like par...
de Mello Zanim M, Rodriguez MC, Martins FDC, Camargos MF, Headley SA.West Nile fever is a zoonotic arboviral disease caused by the West Nile Virus (WNV), responsible for deaths in humans, mammals, and birds with associated neurological manifestations. All previous investigations of WNV from Brazil were based primarily on serological and molecular analyses and in humans, equids, and birds in the northern and southeastern regions of the country. This study describes the pathological and molecular findings observed in a mule, from the state of Paraná, southern Brazil, that died during an outbreak involving equids with clinical manifestations of a neurological dis...
Dos Santos Pinto M, Angeluci GC, Neto JABC, Dos Santos Barbosa I, da Silva Tito RK, Lima SG, Braga VG, Lima VMF, Lucheis SB, Sabioni MS, Kawai JGC....In this research, a seroepidemiological survey was conducted on 202 horses located on 21 properties in the northwestern region of the state of São Paulo (Brazil) to estimate exposure to Leishmania spp., Toxoplasma gondii, and Trypanosoma cruzi. Antibodies against Leishmania, T. gondii and T. cruzi, were detected in 48 (23.76%), 29 (14.36%) and 2 (0.99%) of the 202 horses, respectively. We found a significantly higher occurrence of antibodies against Leishmania compared to those against the other protozoa (Chi-Square = 46.7, 2 d.f., P < 0.001). Seropositivity for the aforementioned prot...
Langlands Z, Gubbins S, Carpenter S, England M.African horse sickness virus (AHSV: Sedoreoviridae; Orbivirus) causes a severe and often fatal disease in horses (African horse sickness: AHS) and is transmitted almost exclusively by Culicoides biting midges (Diptera: Ceratopogonidae). In recent years, unprecedented outbreaks of AHSV have occurred in new geographical foci in Thailand and other related Culicoides-borne viruses continue to emerge unexpectedly, causing disease outbreaks in northern Europe. This study investigated Culicoides abundance and diversity at a donkey (Equus asinus) sanctuary in southern England. The incidence and severi...
Rymaszewska A, Kubiak K, Dmitryjuk M, Rząd I, Kirczuk L.Ixodes ricinus is a widespread vector of numerous microorganisms pathogenic to humans and animals in Europe. The risk of exposure to tick-borne pathogens (TBPs) has increased in recent years due to climate change, the conversion of natural green areas to recreational areas, and growing human and animal populations, including pets. Using molecular methods, the prevalence, diversity, and co-occurrence of selected tick-borne microorganisms were assessed in questing I. ricinus collected from recreational areas (n = 409), in ticks feeding on horses (n = 135), and in blood samples from red d...
Abdulkadir A, Kabir J, Bello M, Olayinka B.Methicillin resistant Staphylococcus aureus (MRSA) represents a worrying example of antimicrobial resistance, and it is essential to acquire new information to monitor the spread and limit it further diffusion. This study aimed to characterise 22 MRSA isolates from horses, dogs, cats, and their human handlers focusing on spa typing. In the analysis of the sequences obtained, the spa type is "unknown" (unidentified) and all the sequences except one had repeats previously not known in all databases potentially indicating new spa-repeats. This could possibly indicate either permanent import of no...
