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.
Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging problem in horses; however, the epidemiology of infection and colonization is poorly understood. This study evaluated factors associated with MRSA colonization at the time of admission to a veterinary teaching hospital. A case-control study evaluating historical factors was performed. Previous colonization of the horse, previous identification of colonized horses on the farm, antimicrobial administration within 30 days, admission to the neonatal intensive care unit, and admission to a service other than the surgical service were...
Fukumoto N, Shibata M, Hayashi M, Kawauchi K, Yabuuchi Y, Oue Y, Matsuyama R, Yamamoto T, Mita H, Kawanishi N, Bannai H, Tsujimura K, Yamanaka T....In 2025, an outbreak of equine influenza occurred among draft horses at Obihiro Racecourse in Hokkaido, Japan. The number of horses showing clinical signs increased dramatically in April. The proportion affected was significantly higher in 2-year-olds than in older groups. The proportion that developed fever during the outbreak was significantly higher than that observed among Thoroughbreds during the 2007 outbreak. In non-epidemic periods, the geometric mean hemagglutination inhibition antibody titer of 2-year-old draft horses was significantly lower than that of 2-year-old Thoroughbreds. The...
Aguirre Siliezar K, Datu C, Proia K, Rotstein D, Nemser SM, Tyson GH, Ragsdale JM, Wilkes RP, Baker RE, Carossino M, Del Piero F, Sasaki E, Yant P....A multi-state outbreak of equine botulism occurred between December 2022 and March 2023 in the United States. Follow-up and testing were performed on 42 horses, including 24 that died or were euthanized in the outbreak that affected ~98 horses. Affected horses had all been exposed to the same commercial feed. Clinical signs included progressive muscle weakness and tremors, recumbency, and colic. No significant gross or microscopic abnormalities were observed on autopsy. Feces and gastrointestinal content were tested for various infectious agents, including botulinum toxin; fecal samples from 2...
Elsawy BSM, Alzan HF., a recently discovered tick-borne hemoparasite infecting equids globally, has significant implications for equine health. Although it is closely related to (sharing 23% genomic divergence), it establishes an asymptomatic carrier state in persistently infected horses, creating a silent transmission reservoir. Its discovery and unique genetics justify its classification as a new taxon. A critical diagnostic challenge is that the lack of the gene in prevents its detection by the standard cELISA, emphasizing the need for species-specific tools. Although species-specific PCR assays, including ...
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...
