Microbiology and horses explores the interactions between microorganisms and equine hosts, focusing on the role of bacteria, viruses, fungi, and other microbes in horse health and disease. This field examines the microbial flora present in various equine environments, including the gastrointestinal tract, skin, and respiratory system, and investigates how these microorganisms influence equine physiology and pathology. Research in this area includes studies on microbial infections that affect horses, the development of antimicrobial resistance, and the impact of probiotics and prebiotics on equine health. This page compiles peer-reviewed research studies and scholarly articles that investigate the diversity, dynamics, and implications of microbial communities in horses, as well as the strategies for managing microbial-related diseases.
Tajima M, Nakajima H, Ito Y.Equine infectious anemia (EIA) virus was observed in thin sections of infected cultured horse leukocytes by electron microscopy. The virus particles had a spherical shape and were between 80 and 120 nm in diameter. Most of them contained an electron-dense nucleoid 40 to 60 nm in diameter. They were observed to form by a process of budding from the plasma membrane and appeared to have thin surface projections. The particles described were not detected in uninfected cultured cells, and their appearance could be prevented by adding EIA immune serum to the inoculum. The implications of these findi...
Rogers HJ.Under a variety of conditions of concentration, Eh, and pH, horse anti- serum and normal horse serum exerted similar bacteriostatic effects against Type A. Ferric iron abolished the bacteriostatic effect when added during the first 2 hours of incubation at Eh+60 mV. Ferrous iron abolished the bacteriostatic effect when added after 3 hours. Ferric iron abolished the bacteriostatic effect at—140 mV. A mixture consisting of horse β- and γ-globulins together with human transferrin exerted a bacteriostatic effect similar to that of whole serum. This system responded in the same way as whole se...
Haque RU.A technique for identifying and characterizing staphylococcal hemolysins by first separating them electrophoretically in barbital-buffered agar gel (pH 8.4) at 5 ma/cm for 2 hr and then determining their hemolytic activities by exposing them to human, horse, rabbit, and sheep erythrocytes is described. The alpha-hemolysin produced by a White variant of the Wood 46 strain of Staphylococcus aureus migrated 18 mm towards the cathode, and it lysed horse, rabbit, and sheep erythrocytes, whereas a Clear variant of the Wood 46 strain of S. aureus produced a lysin which migrated similarly to the alpha...
Goebel WF, Staub AM.1. The immunization of horses with the colicinogenic bacillus E. coli K235 L + O(m) stimulates antibodies which precipitate and neutralize colicine K and neutralize the heterologous colicine I as well. 2. Unlike rabbits, horses evoke predpitating antibodies for the sialic acid-containing polysaccharide colominic acid.
HARDY FM, ARBITER D.Hardy, Frank M. (Fort Detrick, Frederick, Md.), and David Arbiter. Lipid inclusions in L cells associated with Venezuelan equine encephalomyelitis virus infection. J. Bacteriol. 89:1101-1103. 1965.-Venezuelan equine encephalomyelitis (VEE) virus has been shown to induce changes of lipid components within the L cell. Lipid inclusions in the form of dark granular bodies were observed in the L cell after aqueous osmium tetroxide fixation and Sudan black staining. Microscopic examination of cells as early as 8 hr after infection with VEE virus showed an increase in the concentration of these inclu...
BOYD WL, BOYD JW.Boyd, William L. (Ohio State University, Columbus) and Josephine W. Boyd. Viability of coliform bacteria in antarctic soil. J. Bacteriol. 85:1121-1123. 1963.-The distribution of coliform bacteria in soils of Ross Island and the nearby mainland was studied. None was found in almost all of the samples collected, including some from the Adelie penguin rookeries at Cape Royds and Cape Crozier and in soil at the McMurdo Base which had been recently contaminated by human sewage. Samples of pony manure left from previous expeditions were also negative, with one exception where Escherichia coli were p...
VAN UDEN N, DO SOUSA LC, FARINHA M.From the caeca of 252 horses, 503 sheep, 250 goats and 250 swine, 486 yeast isolates belonging to 28 species and 1 variety were obtained. The distribution of the yeasts of any species and for Candida albicans respectively was: horses, 52·4%, 4·4%; sheep, 6·8%, 4·2%; goats, 6·4%, 08%; swine, 88·8%, 9·2%. The suitability of the sheep and goats as hosts for yeasts of any species seems very limited.
The most frequent occurrences for single species were: Candida slooffii in swine (48·4%), Trichosporon cutaneum in horses (21·8%) and Saccharomyces tellustris (Candida bovina) in swine (14%...
ADAMS KM.The ciliate population of the large intestine of the horse shows large, daily variations. The ventral colon is the site where the ciliate fauna varies most. Two species, Cycloposthium edentatum and C. dentiferum, became established in the large intestine after passage through the stomach and small intestine. The introduction of new species into the ventral colon caused significant changes in the fauna of that part of the gut.
Girma T, Chala G, Mekibib B.Epizootic lymphangitis is an infectious and chronically debilitating disease of the equines. Histoplasma capsulatum var. farciminosum, a thermally dimorphic fungi, is the causative agent for the disease. In Ethiopia, the disease significantly affects carthorses, posing threats to animal welfare, and resulting in substantial economic losses. Limited availability of widely accessible antifungals in addition to the chronic nature of the disease is the major challenge against management of epizootic lymphangitis. This study aimed to assess the in vitro efficacy of specific local medicinal plant ex...
Mirabal B, Andrade BS, Souza SPA, Oliveira IBDS, Melo TS, Barbosa FS, Jaiswal AK, Seyffert N, Portela RW, Soares SC, Azevedo V, Meyer R, Tiwari S....Equine strangles is a prevalent disease that affects the upper respiratory in horses and is caused by the Gram-positive bacterium . In addition to strangles, other clinical conditions are caused by the two subspecies, and , which present relevant zoonotic potential. Treatment of infections caused by has become challenging due to the worldwide spreading of infected horses and the unavailability of effective therapeutics and vaccines. Penicillin treatment is often recommended, but multidrug resistance issues arised. We explored the whole genome sequence of 18 isolates to identify candidate p...
Marcelino I, Keizer J, Monti G, Cornelissen P, Santman-Berends I, Lam JH, van der Poel WHM.Monitoring and surveillance of pathogens are crucial for safeguarding animal and public health. While passive surveillance is more common for wild and free-living animals, active monitoring improves the detection and characterisation of specific pathogens relevant to animal and public health. In the (OVP) nature reserve in the Netherlands, an active monitoring system for Heck cattle (), Konik horses () and red deer () has been in place since 1997. This study utilised the data generated from the monitoring system to estimate pathogen prevalence and to evaluate the ongoing monitoring efforts. Y...
Hart KJ, Hegarty MJ, Hart EH.It is more evident that horse health is linked to the gastrointestinal tract and microbial community structure (MCS) as affected by diet. There are many marketed feeds available to enhance nutrition for horses, however the effects of these feeds on hindgut MCS are largely unknown. Objective: The aim was to test the effect of a complementary forage feed (FF) on the fermentation profile and MCS in contrasting basal diets. Methods: A 2×2 factorial design was used to assess the effect of basal diet, forage only (FOR) or forage/concentrate (MIX), and presence/absence of FF on fermentation paramete...
Bustamante CC, Pereira PAM, Fernandes CC, Canola PA, Doria RGS, Costa MC, Valadão CAA.Starch overload induces dysbiosis primarily through a reduction in cecal pH. This study aimed to evaluate the cecal microbiota following excessive starch intake, with or without the administration of an intracecal buffering solution. We hypothesized that the buffering solution would mitigate changes in the intestinal microbiota and associated clinical signs. Ten horses were randomly assigned to two groups, each receiving distinct treatments (Group I: saline solution [WSa] and starch-buffer [SB]; Group II: buffer-water [WB] and starch-saline [SSa]). Following starch overload (17.6 g/kg body wei...
Sévin C, Duquesne F, Copin S, Raguenet V, Guy M, Wilhelm A, Gassilloud B, Moreau P, Petry S.A retrospective review of equine necropsies performed at the Normandy Laboratory for Animal Health, French Agency for food, environmental and occupational health and safety (1996-2022) unexpectedly reported Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio vulnificus in equine samples using API 20NE, prompting a re-evaluation of bacterial identification. Of 27 strains, 25 were cultivable, and re-examined using API 20NE, API 20E, MALDI-TOF, 16S rRNA gene sequencing and Vibrio-specific PCR assays. API 20NE confirmed the original (erroneous) identifications; all Vibrio-specific PCR assays ...
Li M, Lin J, Ma C, Wei G, Hu Q, Li X.L-selenomethionine (L-SeMet), a highly bioavailable organic form of selenium, plays a critical role in maintaining antioxidant homeostasis, regulating reproductive hormone secretion, and improving intestinal microbial ecology. Previous studies have demonstrated that appropriate supplementation with L-SeMet can significantly enhance the production performance and health status of ruminants. However, the nutritional regulatory mechanisms and physiological effects of L-SeMet in monogastric herbivores, particularly horses during mid- to late gestation, remain inadequately understood. Therefore, th...
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 ...
Breton AL, Storme J, Gibbons J, Lewis N.Fungal endometritis is an uncommon uterine condition associated with poor fertility. Objective: This study aimed to 1) provide a descriptive summary of 11 cases of fungal endometritis, 2) assess prevalence trends of fungal endometritis over time, 3) assess fungal species distribution in diagnostic samples, and 4) evaluate the diagnostic accuracy of cytology. Methods: Study 1 reviewed records of 11 mares diagnosed with fungal endometritis for history, presentation, treatment, and outcome. Study 2 analysed 6,727 uterine samples (swabs and lavages; 2019-2024) for factors influencing fungal cultur...
Huguet A-S, Gourbeyre O, Bousquet-Mélou A, Ferran AA, Lallemand EA. is an opportunistic intracellular pathogen responsible for severe respiratory infections in foals, requiring prolonged antibiotic treatment. Despite its susceptibility to multiple antibiotics, the eradication of intracellular remains challenging due to its ability to persist and survive within alveolar macrophages. This study aimed to assess the extracellular and intracellular activity of rifampicin, doxycycline, and four macrolides against while assessing current methodologies used to differentiate intracellular and extracellular bacteria. We found that the removal of extracellular wit...
Bouverat VMA, Pradervand N, Wichert BA, Greim E, Dolf GJ, Gerber V.Hay quality is a key factor in equine respiratory health, with microbiological contaminants in inhaled organic dust posing significant risks. Sensory assessment has been used to evaluate hay hygiene, but its value to identify deficiencies remains unclear. This study aimed to explore the potential of sensory assessment to predict both particulate matter (PM) dust concentrations and microbiological contamination. Fifty hay samples were collected from horse owners and evaluated using a structured sensory examination, microbiological analyses, and dust concentration measurements obtained with the ...
Wei J, Wei L, Ullah A, Geng M, Zhang X, Wang C, Khan MZ, Wang C, Zhang Z.Herbivorous animals rely on complex gastrointestinal systems and microbial communities to efficiently digest plant-based diets, extract nutrients, and maintain health. Recent advances in metagenomic technologies have enabled high-resolution, culture-independent analysis of gut microbiota composition, functional potential, and host-microbe interactions, providing insights into microbial diversity across the herbivore digestive tract. This review summarizes key findings on the gastrointestinal microbiota of herbivores, focusing on ruminant foregut and non-ruminant hindgut fermentation. Ruminants...
Bettio MK, Vidal T, Rose JJ, Jois M, Flavel M, Petrovski S.The gastrointestinal microbiota plays a critical role in horse health and performance. While sugarcane-derived polyphenols have shown microbiota-modulating properties in other species, their effects in horses remain unexplored. Objective: This study investigated whether supplementation with a sugarcane-derived polyphenol feed material modulates the hindgut microbiota of healthy adult horses. Methods: An observational longitudinal study was conducted on six horses over 12 weeks. Faecal samples were collected at three time points: baseline (P1), during supplementation (P2), and post-supplementat...
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...
Boshuizen B, Willems M, De Maré L, Hosotani G, De Oliveira JE, Horemans B, Vidal Moreno De Vega C, Verdegaal EJMM, Delesalle C.Aleurone, a bioactive wheat bran component, has been shown to modulate host metabolism and gut microbiota, but its effects across different compartments of the equine gastrointestinal (GI) tract remain unclear. In this study, we aimed to characterize aleurone-derived metabolite profiles using an fermentation model with digesta from three equine GI compartments (jejunum, cecum, and colon). Unassigned: Three substrates (control feed, aleurone-containing feed, and pure aleurone) were fermented over 72 h, and targeted metabolomics was performed on 38 metabolites. Unassigned: Significant substrate...
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...
Castelain D, Bokma J, Pas ML, Verbanck S, Paepe D, Pardon B, Boyen F.Accurate diagnosis of bloodstream infections is crucial for survival and antimicrobial de-escalation in veterinary medicine. Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry enables faster identification of bacteria in BSIs. This study aimed to compare diagnostic accuracy of two Sepsityper methods (Rapid Sepsityper and Sepsityper Extraction) with conventional culture method for bacterial identification in clinical samples. Mean time-to-positivity and frequency of bacteria in BSIs were also determined. This diagnostic test study used bloodstream infection samples fro...
Schüler MA, Daniel R, Poehlein A.We provide the complete genome of a non-toxigenic strain isolated from horse feces. The strain represents a sub-cluster in the cryptic clade C-III. The genome consists of one chromosome (4,144,784 bp) and one plasmid (10,144 bp) and encodes 3,798 putative genes.
Kubai MA, Roy MM, Stinman CC, Kenne DE, Allbaugh RA, Sebbag L.Bacterial keratitis is a common and serious condition that often leads to vision impairment and potential loss of the eye if not treated promptly and adequately. Topical blood products are often used concurrently with topical antibiotics, helping to mitigate corneal 'melt' from proteases released on the ocular surface. However, blood products are rich in albumin and could affect the efficacy of antibiotics due to drug-protein binding. In this study, serum and plasma samples were harvested from 10 healthy dogs and 10 healthy horses, obtaining fresh and frozen (1 month at -20°C) aliquots for ...
Aydin A, Sudagidan M, Abdramanov A, Yurt MNZ, Mamatova Z, Ozalp VC.Domestic horses could be bred for leisure activities and meat production, as is already the case in many countries. Horse meat is consumed in various countries, including Kazakhstan and Kyrgyzstan, and with the increase in this consumption, horses are registered as livestock by the Food and Agricultural Organization. In this study, horse meat microbiota of horse samples ( = 56; 32 samples from Kazakhstan and 24 samples from Kyrgyzstan) from two countries, Kazakhstan ( = 3) and Kyrgyzstan ( = 1), were investigated for the first time by next-generation sequencing and metabarcoding analysis. The ...
Fernandes CM, Prestes AS, Ianiski LB, Maciel AF, Noro BG, da Silva FD, Vizzotto BS, Botton SA, Schumacher RF, Pereira DIB, Barbosa NV.Pythiosis, caused by Pythium insidiosum, is an infectious and non-transmissible disease affecting horses, dogs, and humans, with no effective drug treatment available. Triazoles are compounds of interest for their potential pharmacological properties against fungi and bacteria. In this study, we synthesized three new triazole compounds (C1, C2, and C3) to assess their in vitro activities against P. insidiosum and their safety on human leukocytes. Susceptibility testing was performed against P. insidiosum isolates (n = 15) to determine the minimum inhibitory concentration (MIC) and minimum ...
Amaral Júnior FP, Souza de Sousa CE, Rafael de Almeida Moreira B, Rodrigues Alves BJ, Longhini VZ, da Silva Cardoso A, Ruggieri AC.There is an important gap in how variations in herbivore dung composition affect GHG emissions on pastures, especially due to differences in dry matter (DM) and nitrogen contents. Oversimplifications can compromise the accuracy of mitigation strategies. This study aims to address this gap by investigating how the chemical composition of dung from different species influences GHG emissions in pasture systems. The results showed that drier dung led to higher cumulative N₂O emissions. The highest emissions were observed from goat at 9.47 mg N-N₂O g⁻ dry soil, followed by sheep at 5.95 mg ...
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 ...
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...
Belhout C, Wang F, Rossano A, Collaud A, Fernandez JE, Marchionatti E, Keller JE, Overesch G, Kaessmeyer S, Schwendener S, Perreten V.Nine Gram-positive, non-motile, facultatively anaerobic cocci, designated EM39Eᵀ, JEK85, 18KM676, 21M1142, 18KM445, 18KM444, 18KM245, 18KM583 and 21KM1573, were isolated from diverse animal material, including horse and pig skin, bovine mastitis milk and feline urine from a urinary tract infection. Phylogenomic analysis based on amino-acid alignment obtained from translated whole-genome sequences; digital DNA-DNA hybridization (dDDH); 16S rRNA, , , and gene comparison; and MALDI-TOF MS spectral profiles placed the strains within the clade. They were closely related to CCM 7100ᵀ, CCM 7...
Tasnim Y, Rahman MK, Awosile B.We aimed to determine the genetic relatedness among β-lactamase-producing Escherichia coli isolated from soil, lake water, and feces of geese, pigs, dogs, cattle, coyotes, wild hogs, and horses at one health interface in West Texas. Results: Previously isolated 56 β-lactamase-producing E. coli isolates from the feces of geese, pigs, horses, coyotes, dogs, cattle, and wild hogs, and soil and lake water from different locations in West Texas were analyzed for genetic relatedness using whole-genome sequencing, core genome multilocus sequence typing, and phylogenetic single-nucleotide polymorphi...
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...
