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...
Arai N, Niwa H, Uchida-Fujii E, Sawa Y, Tamamura-Andoh Y, Kinoshita Y, Momoki A, Watanabe-Yanai A, Iwata T, Kubo M, Kusumoto M.Sequence type 34 (ST34) Salmonella enterica serovar Typhimurium and its monophasic variant (Salmonella 4,[5],12:i:-) are the most prevalent clones among humans and animals worldwide, including in Japan. Although cross-species transmission may have occurred in the background of global spread, the matter remains unresolved. Here, we conducted high-resolution phylogenetic analysis using whole-genome sequencing data of Salmonella Typhimurium and 4,[5],12:i:- obtained from a horse and cattle breeding district in Japan and identified cases of cross-species transmission of ST34 Salmonella 4,[5],12:i:...
Gräf T, Rodriguez MC, de Oliveira Brandão Y, Royer CA, do Nascimento Ferreira C, Confortin C, Zanluca C, Strottmann DM, Duarte Dos Santos CN....Rocio virus (ROCV), a neurotropic arbovirus of the genus, caused Brazil’s largest encephalitis outbreak in the 1970s but has since been rarely detected. We report the first ROCV encephalitis clinical case after nearly 40 years and isolated and sequenced the virus from CNS tissue of a horse. Metatranscriptomics enabled full-genome sequencing, revealing divergence from the reference sequence at an evolutionary rate of 5.8–7.0 × 10⁻⁴, consistent with . Thirty-one non-synonymous substitutions were identified, with the envelope protein most affected. Findings indicate ROCV cryptic circula...
Liu J, Huang X, Wang Y, Wang Y, Luo R, Lu X, Cao K, Xing J, Tu Y, Zheng W.Antibiotic resistance genes (ARGs) are emerging contaminants threatening public health, yet their transmission risk via mare milk products remains understudied. Using metagenomics, we analyzed lactic acid bacteria (LAB)-inoculated fermented, naturally fermented, raw, and pasteurized mare milk to investigate the effect of LAB inoculation on the distribution and transmission pathways of ARGs in mare milk. The results showed that naturally fermented, raw, and pasteurized mare milk had the highest number of pathogens, relative abundance of ARGs, and relative abundance of mobile genetic elements (M...
Kwak ML, Echigo H, Hoketsu T, Taya Y, Numata H, Shiraki Y, Kelava S, Markowsky G, McInnes D, Hayashi N, Nonaka N, Kawai M, Nakao R.The control of ticks is challenging owing to their ubiquity, complex ecologies, and difficulties relating to costs and non-target impacts of chemical control programs. Nature-based solutions centre around co-opting natural processes and biodiversity to address socio-environmental problems; and in some cases, rewilded species can provide nature-based solutions. In northern Japan, the winter ecology of ticks is poorly studied, though some species are believed to overwinter under the snow. Winter grazing activity of rewilded horses may disturb overwintering ticks, exposing them to sub-zero temper...
Narouei M, Rahimi H, Kafshdouzan K.Infections caused by and , as zoonotic diseases, pose a serious threat to the health of humans and animals. To date, there is limited information regarding these diseases in horses. This study aimed to evaluate the prevalence of and in the serum of racehorses in Iran (Golestan province). 350 blood samples were collected from racehorses in four regions of Golestan province, and demographic data (sex, age, and sampling location) were recorded. The collected serum samples were examined by PCR to identify the genomes of and . The results showed that 3.4 % (P < 0.05, 95 % CI: 1.97 % - 5.9 %) of...
Harel B, Sévin C, Le Hello S, Moreau P, Giard JC, Petry S, Gravey F.Enterobacteriaceae are opportunistic pathogens responsible for local or systemic infections in both human and veterinary medicine. To monitor circulating strains in stud farms in Normandy (France), we investigated a collection of Enterobacteriaceae isolated from necropsied equids performed in the region between 1997 and 2020. These strains were initially identified using MALDI-TOF; however, as this method failed to identify some isolates, whole genome sequencing followed by rMLST analysis was subsequently performed. Different genera were identified: Enterobacter spp., Huaxiibacter spp., Lellio...
Zhang Y, Zheng J, Zhang H, Lin Y, Wang Y, Ma Z, Wei J, Zhou B, Zhong D.Getah virus (GETV), Japanese encephalitis virus (JEV), West Nile virus (WNV), and African horse sickness virus (AHSV) are mosquito-borne viruses threatening the health of racehorses. However, the systematic surveillance of these viruses among Shanghai racehorses remains lacking. Therefore, molecular and serological surveillance was conducted for these viruses in racehorses and mosquitoes at horse farms in Shanghai, China, during 2022 to assess their prevalence. Among 11,140 mosquitoes collected from seven farms across four districts, and were identified as the dominant species. RT-qPCR detec...
Wang L, Zheng R, Li Z, Zhang L.Recent increases in cases of western equine encephalitis (WEE) in South America have raised significant concerns about the virus's potential to cause an endemic disease due to its adaptation to mosquito vectors. Currently, there are no effective vaccines or treatments for WEEV, despite ongoing research into various biochemical products in animal models. The virus presents different pathological effects depending on the host. In humans, WEEV infection leads to central nervous system damage, resulting in encephalitis and severe neurological sequelae, which underscores the need for further resear...
Mota RA, Silito IS, Martins MP, Oliveira PRF, Melo RPB, Vieira da Silva V, Jorge FR, Martins TF, Labruna MB.Tick-borne diseases are among the most widespread vector-borne infections, including zoonoses caused by bacterial and protozoal microorganisms. This study consisted of a serosurvey for Rickettsia spp. in 270 horses from 11 farms in the coastal region of Pernambuco, Brazil. Through the indirect immunofluorescence assay (IFA) based on antigens of five Rickettsia species, 164 (60.7%) horses were seroreactive to Rickettsia spp., with seroreactivity among farms ranging from 10 to 100%. Through molecular analysis, all 270 horse blood DNA samples tested negative by PCR assays targeting Anaplasmatacea...
In Italy, West Nile virus (WNV) has been consistently causing disease in humans, horses, and birds since 2008; it was initially confined to the northeast of the country and then spread gradually to the western and southern regions. WNV lineage 1 (WNV-L1) virus was the only lineage that circulated in Italy until 2011, but it was progressively replaced by WNV lineage 2 (WNV-L2). WNV disease in humans was not observed in Sicily, southern Italy, until 2016, when the first case of West Nile neuroinvasive disease (WNND) due to WNV-L1 was reported. Our results demonstrate the introduction of WNV-L2 i...
Djellouli M, Eddaikra N, Beneldjouzi A, Benikhlef R, Ghimire R, Wilkins M, Lafri I.Cutaneous leishmaniosis remains a major public health concern in Algeria, predominantly affecting humans and dogs. However, the role of other animal hosts, particularly equids, in the transmission cycle remains underexplored. This cross-sectional study presents the first systematic investigation of Leishmania spp. exposure and infection in equids, along with associated environmental and host factors, from southeastern Algeria, El Oued Wilaya, the third most affected region for human cutaneous leishmaniasis in the country. A total of 122 equids from eight communes were clinically examined and t...
Pereira EL, Pereira GR, Osório ML, Terra JLA, Gayger JB, Gularte JS, Demoliner M, Pereira VMAG, Filippi M, de Matos QS, Tessman A, Canal CW, Daudt C....Papillomaviruses (PV) are significant agents capable of inducing simple, multiple, and/or proliferative lesions in the dermis and epidermis of animals, known as cutaneous papillomatosis. These lesions can be benign or malignant and have been identified in various hosts, including mammals, birds, reptiles, and fish. PVs are strictly species- and tissue-specific, although some established and unusual cases of cross-infection, such as BPV in equine sarcoids, have been reported. Sarcoids are horses' most common skin tumors, which can be locally aggressive and cause significant clinical signs. It i...
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...
Gholmohammadi S, Malekifard F, Yakhchali M.Ticks are important ectoparasites in equids, causing economic losses in animal husbandry in Iran and worldwide. This study was aimed to determine frequency and species diversity of hard ticks in equids in Ardabil province, during the four seasons in 2021. A total of 240 equids (187 horses, 53 donkeys) were randomly selected and examined. Ixodid ticks were collected from body surface of examined animals and identified. Of all examined equids, 32.5% horses, and 4.58% donkeys were infested with a total number of 412 ixodid ticks. Tick indices (tick number per animal) were 4.62. There was signific...
Taylor WTT, Delsol N, Oelze VM, Mitchell P, Stricker L, Lavin M, Ogundiran A, Hosek L, Barrón-Ortiz CI, Ojediran O, Quintero-Bisono D....Domestic equids were central to the initial colonization of the Atlantic coast of the Americas, a process partially chronicled by historical records. While Spanish colonists brought horses to the Caribbean decades earlier, settlement of the English colony at Jamestown, Virginia, was among the first dispersals of horses to the eastern seaboard. Archaeozoological analysis of identifiable domestic equid remains from two contexts associated with the initial occupation of Jamestown demonstrates intense processing and consumption of the first Jamestown horses during the "Starving Time" winter of 160...
Molazadeh S, Tukmechi A, Hadian M, Dalir-Naghadeh B.This study aimed to determine the prevalence and phylogenetic analysis of Ehrlichia spp. in horses and dogs in Iran. Blood samples were collected from 400 animals, including 200 horses and 200 dogs, from five different provinces in Iran. Polymerase chain reaction (PCR) was used to detect Ehrlichia spp. based on amplification of the 16S rRNA gene. The semi-nested PCR method was used to amplify the dsb, TRP36, and gltA genes. The results showed that 4.5 % of the samples (3 % horses and 6 % dogs) were positive for Ehrlichia sp. The highest prevalence was observed in Kerman and Khuzestan, while th...
: isolates from humans and horses of the equine-associated clonal complexes (CCs) CC1 and CC1660 were comparatively investigated for their genomic relationships. : A total of 91 isolates (64 human, 27 equine) were subjected to whole-genome sequencing (WGS), sequence analysis, and antimicrobial susceptibility testing. : WGS confirmed 75 CC1 and 16 CC1660 isolates, comprising nine sequence types (STs) in CC1 and four STs in CC1660. Ten types were present in CC1 and five in CC1660. In the gene of three CC1 isolates, a 285 bp deletion was detected, and a nucleotide deletion causing a premature...
Eissa N, Salman MB, Younes AM, Mohamed ESA, Abu-Seida AM, Abdulkarim A, Zin Eldin AI.Worldwide, zoonotic diseases represent serious risks to public health, underscoring the need for efficient surveillance techniques. The One Health concept has gained popularity as a comprehensive paradigm for tackling zoonotic disease surveillance because it acknowledges the correlation of pathogens, animals, humans, and the surrounding environment. Public health is now concerned about antibiotic-resistant (), which causes severe impurities in animals and humans, leading to morbidity and mortality. Unassigned: This study examined the collaborative efforts between human and animal (cattle and ...
Azócar-Aedo L, Meniconi G, Pino-Olguín C, Gallardo M.At a veterinary hospital in southern Chile, we conducted an epidemiological study involving domestic dogs, cats, and horses to determine the seropositivity for pathogenic spp., identify the infecting serogroups, measure antibody titers, and characterize seropositive animals by sex and age. None of the sampled animals showed clinical signs of leptospirosis. The microscopic agglutination test, using a panel of eight serogroups, was used for diagnosis. The seropositivity was 36.5% (95% confidence interval [CI] = 24.5-48.4) in dogs, 12.9% (95% CI = 2.6-23.1) in cats, and 45.2% (95% CI = 30.1-60.2...
Chwirot A, Niedźwiedź A, Stygar D, Siwińska N, Paszkowska M, Niżański W, Napierkowska S, Migdał P, Kublicka A, Marynowska M, Matczuk A....This study investigated the presence of antibodies to human adenovirus type 36 (HAdV-D36) in horses with different metabolic statuses, including normal, overweight, and those diagnosed with equine metabolic syndrome (EMS). A total of 151 serum samples were tested, of which 47.6% were positive for anti-HAdV-D36 antibodies. Although the horses were confirmed to be susceptible to HAdV-D36 infection, there was no significant correlation between infection and blood glucose or cholesterol levels. However, the triglyceride levels showed significant differences-they were particularly elevated in the s...
Falsini A, Coppola C, Fiori A, Buonavoglia D, Marchi S, Montomoli E, Pellegrini F, Lanave G, Martella V, Camero M, Trombetta CM.Influenza D virus (IDV), belonging to the family, was first discovered in 2011 in pigs. Surveys in humans and animals have been carried out to decipher IDV ecology. In this seroepidemiological study, we investigated the circulation of IDV lineages across Italy in livestock and wildlife animals. A total of 1038 animal serum samples (from 246 bovines, 249 swine, 98 equines, and 445 wild boars) were tested using hemagglutination inhibition and virus neutralization assays. The results confirm bovines as the primary reservoir for IDV, with high seroprevalence for both D/660 (87%) and D/OK (80%) st...
Al-Rammahi HM, Mohsen RK, Othman RM.West Nile virus (WNV) circulates between birds and mosquitoes, with horses and humans as incidental dead-end hosts. Despite documented cases in neighboring countries and human cases in southern Iraq, no previous studies have investigated WNV in Iraqi horses. Unassigned: To determine the seroprevalence of WNV in horses from three southern Iraqi governorates (Thi-Qar, Misan, and Basrah) between March and June 2024. Unassigned: Blood samples were collected from 236 horses regardless of age, sex, or health status. Serum samples were analyzed using commercial competitive enzyme-linked immunosorbent...
Mojsiejczuk L, Whitlock F, Chen H, Magill C, Aranday-Cortes E, Bone J, Tong L, Da Silva Filipe A, Bryant N, Newton JR, Chambers TM, Reedy SE....Influenza A viruses (IAVs) are prime examples of emerging viruses in humans and animals. IAV circulation in domestic animals poses a pandemic risk as it provides new opportunities for zoonotic infections. The recent emergence of H5N1 IAV in cows and subsequent spread over multiple states within the USA, together with reports of spillover infections in humans, cats and mice highlight this issue. The horse is a domestic animal in which an avian-origin IAV lineage has been circulating for >60 years. In 2018/19, a Florida Clade 1 (FC1) virus triggered one of the largest epizootics recorded in the ...
Pinho APVB, Ferreira F, Fuck JJ, de Oliveira JP, Dias RA, Grisi-Filho JHH, Heinemann MB, Telles EO, Amaku M, Ferreira Neto JS.Considering that control strategies for Equine Infectious Anemia, based on the serological diagnosis of equids and the removal of positive animals, may not be optimal for developing countries with an absolute predominance of grade working animals, this study aimed to address this issue based on the epidemiological situation of the disease in Pará, a state in the Brazilian Amazon. Pará was divided into five regions, and within each region a pre-established number of farms were randomly selected. Within each farm, a pre-set number of animals were randomly selected and submitted to Agar Gel Imm...
Kloster H, Stormo C, Haaland AH, Stuen S, Kjelland V. ticks play a crucial role as carriers of diseases, transmitting pathogens to vertebrate hosts, including horses. This study aimed to investigate the seroprevalence of IgG antibodies against sensu lato (s. l.), , and tick-borne encephalitis virus (TBE-virus) in equine sera collected in southern Norway. In total, sera from 331 horses stabled in four counties (Agder, Vestfold and Telemark, Vestland, and Viken) were analyzed by immunoblot. In total, 66% of the horses were IgG-seropositive for antibodies against one or multiple tick-borne pathogens. The highest seroprevalence was detected against...
da Silva VV, de Sá Barreto Maia Leite DP, de Crasto Souza Carvalho Reis J, de Almeida Braz BM, Junior JWP, de Almeida JC, Mota RA.This study identifies high-risk areas for Equine Infectious Anemia (EIA) in Brazil and analyzes the temporal trend of the disease across regions and Federative Units over an 18-year period (2006-2023), using data from the National Animal Health Information System (SIZ). During the analyzed period, 111,826 cases of EIA were reported in Brazil, with a predominance in the Northeast (39.75 %), Central-West (27.56 %), and North (20.95 %) regions. The state of Mato Grosso recorded the highest number of cases (17.02 %), while Sergipe had the lowest (0.36 %). In the incidence risk analysis, the s...
Houben RMAC, van Maanen C, Newton JR, van den Broek J, Sloet van Oldruitenborgh-Oosterbaan MM, Heesterbeek JAP.Equine herpesvirus 1 (EHV-1) infection is the cause of high impact disease syndromes, affecting the global horse industry. The effect of vaccination on transmission dynamics of EHV-1 in naturally occurring outbreaks is not quantified. Our aims were to estimate R for EHV-1 in equine populations from outbreak data, and evaluate the effect of vaccination status of the herd on R through a systematic review, model-based estimations and meta-analysis. A literature search for outbreak reports was carried out. Depending on available data, the early epidemic growth rate (GR) or final attack rate (AR) a...
Suganuma K, Fujita G, Macalanda AMC, Regilme MAF, Izumida H, Inoue N, Acosta TJ.Horseflies are pests that cause discomfort from blood-sucking and disease transmission, and economic losses in the equine industry. This study evaluated the efficacy of horsecloth impregnated with icaridin in reducing horsefly attacks and deterring horseflies. Repellent activities were evaluated under three conditions: treatment 1 (no horsecloth), 2 (horsecloth without icaridin), and 3 (horsecloth impregnated with icaridin), using three native Hokkaido horses (Dosanko) and three mixed-breed horses (Dosanko and Haflinger) in July 2023 at a riding horse club in Hokkaido, Japan. Treatment 3 signi...
Muñoz-Caro T, Gavilán P, Villanueva J, Oberg C, Herrera C, Fonseca-Salamanca F, Hidalgo A.Parasitic infections are among the most important causes of morbidity and mortality in horses worldwide. In the Andean mountainous regions of Chile, horses are a highly valued specie, playing a key role as working animals also providing support in cattle transhumance grazing into high mountainous areas during dry season. The breeding and maintenance of horses in the mountainous region of La Araucanía in Chile is a key issue allowing to the subsistence economy of communities with a strong ethnic component represented by Mapuche-Pehuenche origin families. However, the health status of these ani...
Uprety T, Soni S, Sreenivasan C, Hause BM, Naveed A, Ni S, Graves AJ, Morrow JK, Meade N, Mellits KH, Adam E, Kennedy MA, Wang D, Li F.Equine rotavirus species A (ERVA) G3P[12] and G14P[12] are two dominant genotypes that cause foal diarrhoea with a significant economic impact on the global equine industry. ERVA can also serve as a source of novel (equine-like) rotavirus species A (RVA) reassortants with zoonotic potential as those identified previously in 2013-2019 when equine G3-like RVA was responsible for worldwide outbreaks of severe gastroenteritis and hospitalizations in children. One hurdle to ERVA research is that the standard cell culture system optimized for human rotavirus replication is not efficient for isolatin...
