Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Microbiology
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.
Fecal microbiota of weaned equine and mule foals grazing bermudagrass pastures. Weaning is a critical period in the lives of foals. After weaning, forage consumption represents a major challenge for both equine or mule foals. Objective: This study evaluated the fecal bacterial concentration, composition, diversity and differential abundance in weaned equine and mule foals under rotational grazing on Bermudagrass (Cynodon spp.) pasture. Methods: A randomized design was used with equine and mule foals grazing two rotations on three Bermudagrass cultivars (Coastcross, Florakirk, and Tifton-85). Pasture rotation occurred every 20 days. The first rotation was evaluated at 20, ...
Screening Equine Skin and Mucous Membranes for Carriage of Coagulase-Positive Staphylococci. Commensal populations of coagulase-positive Staphylococcus spp. (CoPS) in healthy horses are not well-defined. Objective: To determine the point prevalence, anatomical distribution, antimicrobial susceptibility and genomic characteristics of CoPS in healthy horses. Methods: One-hundred and fifty privately owned, systemically healthy horses from seven facilities were enrolled in this study. Methods: Horses were sampled from the nares, buccal mucosa and three skin sites. Isolates were identified using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry, and antimicrobial...
Detecting and measuring respiratory events in horses during exercise with a microphone: deep learning vs. standard signal processing. Monitoring respiration parameters such as respiratory rate could be beneficial to understand the impact of training on equine health and performance and ultimately improve equine welfare. In this work, we compare deep learning-based methods to an adapted signal processing method to automatically detect cyclic respiratory events and extract the dynamic respiratory rate from microphone recordings during high-intensity exercise in Standardbred trotters. Results: Our deep learning models are able to detect exhalation sounds (median F1 score of 0.94) in noisy microphone signals and show promising r...
Antibiotics in Veterinary Ophthalmology: Resistance, Stewardship, and Emerging Antibiotic-Sparing Strategies. Antimicrobial resistance (AMR) is a growing challenge in veterinary ophthalmology, particularly in cases of bacterial keratitis, where progressive stromal infection can threaten vision and globe integrity within hours to days. This review synthesizes current evidence on pathogen distribution, antimicrobial susceptibility profiles, multidrug resistance (MDR) prevalence, and determinants of nonsusceptibility in veterinary patients, highlighting the emerging role of antibiotic-sparing alternatives. Across contemporary studies, Staphylococcus pseudintermedius, β-hemolytic streptococci, and Pseud...
Complete genome of Bacillus anthracis strain ter21 from an infected zoo pony in Ternopil, Ukraine, 2021. Using rapid nanopore whole-genome sequencing, we assembled the genome of strain ter21 (5,229,480 bp), a Tsiankovskii-I group isolate cultured from a fatal case in 2021 of a pony from a zoo in Ternopil, Ukraine, identifying virulence plasmid pXO1 that encodes anthrax toxin, and pXO2.
Phage Therapy for a Refractory and Multidrug-resistant Equine Surgical Site Infection. A 14-year-old American Quarter Horse mare developed a refractory deep surgical site infection following emergency celiotomy for acute right dorsal large colon displacement with 180° volvulus. Initial cultures revealed a high-burden polymicrobial infection with and , associated with delayed healing, and later followed by multidrug-resistant , further limiting therapeutic options. Phage therapy was initiated using a customized lytic phage cocktail administered topically on a daily basis over a 35-day period, with cocktail composition guided by daily wound culture results. Phage therapy markedl...
The Occurrence of Bacterial Infections in Equine Wounds and Abscesses in Horses from 2019 to 2023. Bacterial infections in equine wounds are common and can complicate treatment and healing. This five-year retrospective study examined 2844 samples from wounds and abscesses from horses in Germany (2019-2023), analyzing bacterial prevalence by care setting and geographical region. A total of 4464 bacterial isolates were identified, with β-hemolytic streptococci (20.6%), (15.6%), and (13.0%) being the most common. Methicillin-resistant (MRSA) accounted for 35.9% of isolates. Resistance to third- and fourth-generation cephalosporins was detected in 15.2% of isolates. Samples from clinics s...
Bacteroides fragilis – an overlooked cause of abortion in the mare? A near late-term pregnant mare developed purulent vaginal discharge, fever and peripheral edema. Preterm foaling was medically induced, and the mare delivered a weak foal that was subsequently euthanized. Necropsy revealed an extensive, severe allantochoroiditis affecting the entire corpus segment. Necrosuppurative choroiditis with multiple colonies of gram-negative bacilli and suppurative bronchioalveolitis was found at histology. Anaerobic culture of the chorion revealed a mixed culture clearly dominated by Bacteroides fragilis. B. fragilis has not previously been associated with abortion in...
Prevalence, genomic diversity and emerging antimicrobial resistance of Taylorella asinigenitalis in Grand Noir du Berry breeding donkeys. Taylorella asinigenitalis is a fastidious Gram-negative bacterium of the equine genital tract, found more commonly in donkeys than horses. Although considered non-pathogenic, it is closely related to Taylorella equigenitalis, the agent of contagious equine metritis, and has been linked to experimental and natural cases of endometritis. The SAFRAN project (French acronym for "Sauvegarde de la fertilité de l'âne", meaning "Preservation of donkey fertility"), launched in 2024 by the French National Research Institute for Agriculture, Food and Environment (INRAE) with support from the Centre-Val...
Impact of collagen supplementation on the fecal microbiome of young horses in training. Intense training in athletic foals may alter fecal microbiota, highlighting the need for nutritional strategies such as hydrolyzed collagen supplementation. Objective: This study aimed to evaluate the effects of dietary hydrolyzed collagen on the fecal microbiome of weanlings in training. Methods: Twenty Mangalarga Marchador foals (206 ± 18 kg; 7 ± 1 mo age) were assigned to two groups: a supplemented group (50 g/day of hydrolyzed collagen for 180 days) and a control group. A completely randomized design with repeated measures over time was used. Foals were exercised five consecutive days pe...
Evaluation of autologous fecal microbiota transplantation for restoring equine gut microbiota after antibiotic-induced dysbiosis. Microbial resilience is important to maintain a healthy gut environment in horses, especially after antibiotic administration, but the efficacies of post-antibiotic recovery strategies remain poorly characterized. We used microbial amplicon sequencing to compare spontaneous recovery, autologous fecal microbiota transplantation (FMT), and probiotic administration in 18 horses following antibiotic-induced dysbiosis. Clinically healthy horses received a combination of cephalothin and minocycline for 5 consecutive days before intervention. Fecal microbial recovery was longitudinally evaluated by u...
Comparative metagenomic analysis of gut microbiomes in Yunnan ponies and Dutch warmblood horses. The Yunnan pony is an officially protected pony breed in China. However, its gut microbiome characteristics remain largely unexplored. This study aimed to compare the gut microbiome and antibiotic resistance genes (ARGs) profiles between Yunnan ponies and Dutch warmblood horses. Unassigned: A total of 14 fresh fecal samples were collected from Yunnan ponies and Dutch warmblood horses. Metagenomic sequencing was employed to comprehensively analyze and compare the gut microbial composition, function, and ARGs profiles between the two breeds. Unassigned: The results showed no significant differen...
Genomic diversity of multidrug-resistant Rhodococcus equi: novel sequence types, pangenome architecture, and phylogenomic evolution. Rhodococcus equi is a major cause of life-threatening pneumonia in foals under 6 months of age and an opportunistic pathogen in immunocompromised humans. Although common in soil and equine farm environments, its evolutionary dynamics, virulence architecture, and pathways of antimicrobial resistance (AMR) emergence remain poorly understood. This study integrated phenotypic characterization and whole-genome sequencing of 46 R. equi isolates from horses submitted for necropsy (n = 45) and equine fecal samples (n = 1) in Kentucky between January 2022 and December 2023 to define their resistance la...
Prevalence, risk factors, and antimicrobial resistance of Staphylococcus aureus in equines in Egypt. Staphylococcus aureus is a common commensal organism in both humans and animals, frequently colonizing the skin and nasal cavities of healthy individuals, although it can also cause a wide range of severe infections. The present study investigated the prevalence and risk factors of S. aureus in equines, along with antimicrobial resistance patterns of methicillin-resistant S. aureus (MRSA) isolates. The results revealed a prevalence of 38.6% in nasal samples collected from equines, highlighting the organism's significant presence and potential to cause infections in these animals. A genotypic p...
Cross-protective effect of a multicomponent fusion protein vaccine during a natural episode of Streptococcus zooepidemicus respiratory disease in ponies. Streptococcus equi subspecies zooepidemicus is a highly diverse opportunistic pathogen of horses, associated with respiratory disease and endometritis. Objective: To characterise S. zooepidemicus isolates recovered from young ponies during a natural episode of respiratory disease, and to determine if vaccination with Strangvac®, a vaccine against Streptococcus equi subspecies equi, conferred cross-protection. Methods: Retrospective analysis of a double-blinded placebo-controlled study involving 32 ponies (16 vaccinates and 16 placebo controls) that experienced a natural episode of respiratory...
Cheek tooth extraction in geriatric versus non-geriatric horses. Age-related dental changes are major contributors to dental disorders in older horses, and cheek tooth extractions are often required to maintain masticatory function and oral comfort. However, limited information is available on clinical and treatment characteristics in this older patient population. Objective: To describe clinical features, treatments, complication rates and short-term outcomes of horses undergoing oral cheek tooth extraction and treatment of odontogenic sinusitis, and to compare findings between geriatric and non-geriatric horses. Methods: Retrospective analysis of clinical...
Integrative and conjugative elements carrying high-level gentamicin resistance genes in Streptococcus dysgalactiae subsp. equisimilis from horses. In streptococci, the acquisition of high-level gentamicin resistance (HLGR) abolishes the synergy with beta-lactams, constituting a medical concern for humans and animals. This synergy between gentamicin and beta-lactams is useful to treat severe infections like endocarditis, among others. HLGR has been characterized mostly in roup B Streptococci mediated by the bi-functional gene (6)-(2).HLGR- subsp. () (=27) were isolated from the uterus of mares during a routine screening before fecundation. One HLGR- was isolated from a lymph node of a mare. The mares resided in six different studs locat...
Effects of Dietary Zinc Cysteamine Supplementation on Growth Performance, Physiological Responses, and Fecal Microbiota in Weaned Foals. Zn-CS chelate has shown beneficial effects on gut health and growth in piglets, but its impact on weaned foals remains largely unknown. This study evaluated the effects of dietary Zn-CS supplementation on growth performance, nutrient digestibility, physiological status, and fecal microbiota in weaned Ili foals. Thirty-two six-month-old foals were randomly assigned to four treatment groups receiving 0, 2, 4, or 6 mg Zn-CS/kg body weight per day for 90 days. Growth performance, nutrient digestibility, plasma biochemical parameters, liver function enzymes, serum hormones, antioxidant indices, fec...
Growth kinetics of Taylorella equigenitalis and its survival in straw-based bedding. Taylorella equigenitalis, the causative agent of contagious equine metritis, is a fastidious bacterium with limited tolerance to extra-host conditions; however, quantitative data on its growth dynamics and survival outside the host remain scarce. This study evaluated the growth of T. equigenitalis under aerobic and microaerophilic conditions in liquid medium and its survival in wet and dry straw-based bedding under controlled laboratory conditions.Growth was assessed at 20 °C and 37 °C using real-time optical density monitoring and viable cell counts. No proliferation was observed at 20 ...
Alkaline-Promoted Hydrothermal Liquefaction of Polo Horse Manure for Biocrude Production. Horse manure (collected as pure feces) is a high-moisture, nutrient-dense organic waste stream with potential for valorization via hydrothermal liquefaction (HTL). However, catalyst selection is often reported without direct catalyst-class comparisons under identical conditions. In this study, manure collected in Thailand was characterized and converted via noncatalytic and catalytic HTL in a batch reactor at 300 °C for 40 min (feedstock/water = 1:10, w/w; heating rate 10 °C min). Four catalysts (KOH, NaOH, HPO, NH·HO) were evaluated at 10 and 20 wt % (dry feed basis), with biocrude recover...
Clinical audit on antimicrobial stewardship effectiveness in reducing antimicrobial-resistant bacterial colonisation in hospitalised horses. International guidelines support the One Health approach and recommend antimicrobial stewardship programmes (ASPs) in veterinary medicine. National data on antimicrobial-resistant bacterial colonisation rates (AMRb CR) in horses remain limited. Objective: To evaluate the effectiveness of an ASP in reducing AMRb CR in a Veterinary Teaching Hospital using a clinical audit. Methods: Clinical audit. Methods: In Autumn 2021 active AMR surveillance in Perinatology/Reproduction and Internal Medicine Units planned; January-July 2022-first audit cycle (A1); Autumn 2022-review and implementation of anti...
Vaginal host-microbe signatures linked to placental outcomes in mares. Ascending placentitis is a leading cause of late-term pregnancy loss in mares. Although pathogens are presumed to ascend from the caudal reproductive tract, the association between the vaginal microbiome and placentitis has not been systematically examined. Objective: To characterise microbial and host gene expression in the equine vagina during gestation and to identify taxa or transcripts that were associated with the presence of an abnormal placenta at birth. Methods: Prospective, paired observational study. Methods: Vaginal wall swabs were collected from 49 multiparous Thoroughbred mares a...
Insights from healthy mares reveal that mammalian uteri harbor a diverse virome. The Earth's estimated 10 virions, primarily phages, significantly impact microbial ecosystems. Despite their abundance, viromes remain relatively understudied-particularly in domestic animals. While recent studies have described a dynamic commensal microbiome in mammalian uteri, no research has yet characterized the commensal virome in a mammalian uterus. In this study, we report for the first time the presence of a sparse, but diverse native virome in the equine uterus. The resulting virome database consists of 513 non-redundant viral genomes (> 2 kb). Taxonomic annotations revealed the...
Long-Read Sequencing for Species-Level Resolution of the Equine Gut Microbiota Reveals the Need for Improved Databases. Differences in gut microbiota composition related to diet have been reported in horses, but characterization of specific microbial taxa remains limited, particularly at the species level. The objective of this study was to use long-read sequencing of the 16S rRNA gene to provide additional taxonomic insight into the intestinal microbiota in horses. Fecal samples were collected from 12 horses on pasture and from 6 of them after switching to a hay diet. Sequencing yielded low read counts per sample, and the analysis failed to detect statistical differences in alpha- and beta-diversity among diet...
A novel flowable calcium silicate cement for endodontic therapy in equine teeth. Equine endodontic treatment for apical infections is performed infrequently due to anatomical and accessibility challenges of equine cheek teeth. However, the alternative of extraction is not without risk and lifelong implications for the horse. Mineral trioxide aggregate (MTA), a calcium silicate cement (CSC), has been used successfully in human dentistry for decades. MTA and other CSCs demonstrate excellent biocompatibility with favourable antimicrobial and physicochemical properties. These characteristics may support their application as an alternative filling material when used in equine e...
The Equine Reproductive Microbiota: Composition, Dynamics, Dysbiosis, and Implications for Fertility in Mares and Stallions. The equine reproductive microbiota has emerged as an important factor influencing reproductive health and fertility in both mares and stallions. Traditionally, the equine uterus was considered sterile, and microbial presence was interpreted primarily in the context of infection. However, sequencing-based studies have demonstrated that the reproductive tract, including the uterus and semen, contains detectable microbial communities or microbial DNA signatures, challenging this traditional paradigm. In mares, the vaginal microbiota is consistently dominated by , , , and , whereas the uterine env...
The Effects of L-Citrulline on the Apparent Digestion and Metabolism of Nutrients, Blood Hormone Levels, Amino Acid Metabolism and the Diversity of Faecal Microbiota in Mares in the Later Stage of Pregnancy. This study aimed to investigate the impact of dietary L-citrulline supplementation on the health of mares during late gestation. Thirty-two healthy mares in late pregnancy were randomly assigned to four groups: a control group (CON, 0 g/d) and three treatment groups receiving 15, 30, and 45 g/d/head of L-citrulline, respectively. The trial spanned 72 days, including a 12-day adaptation phase and a 60-day formal feeding period. A fixed daily feeding amount of 11.2 kg/head was provided, ensuring complete consumption and consistent dry matter intake across all groups. Results demonstrated that su...
Nano-Encapsulated Vitamin E Enhances Cryo-Resistance of Stallion Spermatozoa: A Comprehensive Evaluation of Sperm Quality, Kinematic Parameters, Antioxidant Capacity, Microbiota and Ultrastructure. This experiment explores the comparative ability of vitamin E (VE) and its nano-emulsion (VEN) in enhancing cryo-resistance of stallion spermatozoa by examining semen quality, kinematic variables, acrosome integrity, apoptosis, antioxidant capacity, ultra-structural alterations and microbiota of cryopreserved stallion sperm. Semen from five stallions (8-10 years) was cryopreserved with 0.1 or 1 mM of VE or VEN; and a non-additive group served as the control. The VEN particles ranged in size from 72 to 172 nm, with a mean diameter of 287 nm. Supplementation with VE (1 mM) or VEN (0.1 ...
Horse racing towards antibiotic resistance. Accompanying animals as a source of antibiotic-resistant bacteria. Antibiotic resistance is a significant issue in modern infectious medicine and veterinary science, with animals, including horses, playing a crucial role in its dissemination. Antibiotics, used both for treatment and prevention of diseases in animals, influence the composition of the microbiota and promote the selection of resistant strains that can be transmitted to humans through direct or environmental contact. Horses, currently classified as companion animals, serve as a reservoir of commensal and pathogenic bacteria, including multidrug-resistant strains capable of horizontal gene transfe...
Circulating microRNA profiles as diagnostic and prognostic biomarkers for acute and carrier Theileria equi infection. Equine piroplasmosis caused by Theileria equi exhibits a wide clinical spectrum ranging from acute disease to lifelong asymptomatic carriage, posing significant diagnostic and epidemiological challenges. In this cross-sectional case-control study, equines were classified as acutely infected, asymptomatic carriers, or uninfected controls based on clinical examination and quantitative PCR. Hematological and biochemical alterations were assessed, and plasma miRNA profiles were characterized using small RNA sequencing, followed by qRT-PCR validation of selected miRNAs. Cytokine gene expression in ...
