Topic:Digestive Tract
The digestive tract in horses is a complex system responsible for the breakdown and absorption of nutrients essential for maintaining equine health. It includes several key components: the mouth, esophagus, stomach, small intestine, cecum, large colon, small colon, and rectum. Each segment of the digestive tract performs specific functions, from the mechanical breakdown of feed to the enzymatic digestion and absorption of nutrients. The horse's digestive system is uniquely adapted to process fibrous plant material, relying heavily on microbial fermentation, particularly in the hindgut. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and function of the equine digestive tract, as well as common disorders and their management.
Analysis of the antitrypsin activity and immunoglobulin G concentration in equine colostrum and milk. Immunoglobulins ingested via colostrum must remain intact to be absorbed by the neonate. Equine colostrum contains antitrypsin activity, which likely protects these proteins from proteolysis in the gastrointestinal tract. Objective: To quantify antitrypsin activity in equine colostrum and milk, describe its temporal changes during the first five days after parturition, compare actitvity between left and right mammary glands, evaluate differences between nulliparous and pluriparous mares, and examine associations with immunoglobulin G (IgG) concentrations and mare age. Methods: This retrospecti...
Functional and molecular characterization of equine intestinal organoids across media conditions and intestinal segments. Gastrointestinal (GI) disease is a major cause of morbidity and mortality in horses, with disruption of the intestinal epithelial barrier playing a central role in disease pathogenesis. A deeper understanding of the molecular and functional properties of the equine intestinal barrier is essential to improve diagnostics and therapeutics. While intestinal organoids have emerged as a promising tool for modeling GI physiology and disease, equine-specific data remain limited. Existing studies vary in methodology and often lack functional characterization, particularly across different intestinal re...
Vonoprazan pharmacokinetics and effects on gastric pH following administration to fed and fasted horses. Current treatment options for equine gastric ulcer syndrome (EGUS), such as omeprazole-a proton pump inhibitor (PPI)-have notable limitations, including the need for administration on an empty stomach. Potassium-competitive acid blockers (P-CABs), such as vonoprazan, are a newer class of acid suppressants that offer several advantages over PPIs in humans and may provide similar benefits in horses. Objective: To describe the pharmacokinetics and effect of a single oral dose of vonoprazan on intragastric pH in horses. We hypothesised that vonoprazan would follow linear kinetics across the doses ...
Laparoscopically assisted cecal cannulation in standing horses. Access to the equine cecum is required for various therapeutic and experimental procedures, including decompression, fluid therapy, and transfaunation. Traditional approaches via laparotomy are highly invasive. This study aimed to describe a minimally invasive, laparoscopically assisted technique for cecal cannulation in standing horses. Unassigned: Seven horses underwent the procedure under sedation and paravertebral anesthesia. Two right flank accesses were created: a 10-mm laparoscopic port for visualization and a 2-cm minilaparotomy for cecal exteriorization. A Foley catheter was inserted ...
The horse gut bacteriome and anaerobic mycobiome are influenced by seasonal forages and small intestinal starch digestibility. The equine gut microbiome is a complex and dynamic ecosystem, housing a diverse consortium of bacteria and anaerobic fungi (AF) capable of breaking down complex plant matter and converting it into vital energy sources for their host. The aim of this study was to broaden our current understanding of bacterial and AF diversity in the equine hindgut and how it differs between cohorts and responds to dietary shifts. Results: Faecal samples were collected from 48 horses and the bacteriome and anaerobic mycobiome analysed using long-read amplicon sequencing. Samples were collected from racehorses (R...
Radiographic area of large intestinal sand accumulation in horses may determine clinical significance. Sand enteropathy is a common disease in horses worldwide. The presence of sand does not always cause disease. The amount of sand required to cause clinical disease is not well established. Objective: To establish a weight-indexed cut-off for the diagnosis of clinically relevant sand enteropathy based on radiographic area. Methods: Cross-sectional. Methods: Abdominal radiographs were acquired from clinically normal horses and compared with horses with clinical sand enteropathy. Sand area and sand area per kilogram of body weight were calculated. A receiver operating characteristic (ROC) curve w...
Assessment of Salivary Biomarkers of Gastric Ulcer in Horses from a Clinical Perspective. This study arises from the search for non-invasive diagnostic alternatives for equine gastric ulceration (EGUS), which is prevalent, clinically variable and only confirmed by gastroscopy. The aim is to quantify five salivary biomarkers (IL1-F5, PIP, CA VI, serotransferrin, albumin) under clinical conditions by validated assays and analyse their diagnostic value. Horses were grouped in No EGUS (neither clinical signs of EGUS nor gastric lesions), EGUS non-clinical (apparently no clinical signs of EGUS but with gastric lesions), and EGUS clinical (obvious clinical signs of EGUS and with gastric ...
Advanced equine duodenoscopy technique. Duodenal pathologies are underreported in equine medicine, probably not due to little occurrence, but due to the limitations of current diagnostic techniques. The aim of this report is to describe a novel duodenoscopic approach, that allows a complete visualization of a region inaccessible via standard techniques. Gastroduodenoscopy was performed in a clinical setting in 60 adult horses referred to us due to complaints suspected to be related to gastroduodenal diseases. The initial steps of the procedure were performed using previously published techniques. Once the video-endoscope reached the...
Sources of Environmental Exposure to the Naturally Occurring Anabolic Steroid Ecdysterone in Horses. Ecdysterone controls moulting and reproduction in insects, crustaceans, and helminths. It is also produced by many plants, probably as an insect deterrent. The steroid is not made by vertebrates but has anabolic effects in mammals and could be useful for treating sarcopenia in aged horses. However, ecdysterone is banned in horseracing and equestrian sports, and with no limit of reporting, the risk of unintended exposure to this naturally occurring prohibited substance is a concern. To explore this risk, pasture plants and hay samples were analysed for ecdysterone content, as well as samples of...
Exploring the distinctive characteristics of gut microbiota across different horse breeds and ages using metataxonomics. Gut microbiota exerts a pivotal function in host nutrient metabolism and maturation of the mucosal immunity. Analyzing the reciprocal interaction between horses and gut microbiota constitutes a crucial aspect of scientific feeding practices. This study aims to investigate the differences in gut microbiota among Hequ horses, Mongolian horses, and Thoroughbred horses, as well as between Thoroughbred horses at two age stages. Unassigned: Paired-end sequencing with a read length of 2×250 bp targeting the V3-V4 region of the 16S rRNA gene in fecal samples was carried out. Subsequently, differences...
Identifying insulinemic responses of ID horses offered varying levels of NSC and meal-sizes. Feeding small meals (∼1 g/kg BW DM basis) providing >10% nonstructural carbohydrates (NSC; starch + water soluble carbohydrate; WSC) has resulted in an augmented insulin response (AIR) in insulin dysregulated (ID) horses, but it's unclear if AIR reflects NSC content or the g NSC/kg BW/meal. Objective: The insulinemic responses of ID (n = 7) and non-insulin dysregulated (NID; n = 8) horses fed four feeds (A = 6.8% NSC; B = 14.9% NSC; C = 35.5% NSC; D = 44.6% NSC) at three levels of NSC intake (0.06, 0.11-0.12 and 0.17-0.18 g/kg BW) were evaluated in a randomized Latin square design across two...
Impact of Low-Starch Dietary Modifications on Faecal Microbiota Composition and Gastric Disease Scores in Performance Horses. Equine gastric disease (EGD) is a common condition in performance horses (), potentially compromising behaviour, performance, and welfare. EGD is often attributed to high-starch, high-sugar feeds and limited forage. Evidence for diet-induced changes on digestive microbiota is lacking. Nine elite showjumping horses were housed at the same performance yard with standardised diet and management throughout the study. Horses were transitioned from a high-sugar and -starch (31%) feed to a low-starch and -sugar (16.5%) concentrate feed. Gastroscopies, blood, and faecal samples were taken pre- and 12 ...
Could Mesquite (Prosopis juliflora) Help Control Gastrointestinal Parasites in Horses? Exploring new natural-origin antiparasitic alternatives is essential in addressing the resistance issues that have emerged due to the widespread use of chemical or synthetic antiparasitic compounds. This area remains relatively underexplored despite the increasing recognition of plants like (mesquite) for their antiparasitic properties and nutritional value as a high-protein animal feed. This review aims to investigate the antiparasitic potential of against gastrointestinal parasites in horses. The review incorporates sources from 2005 to 2024. It was found that various phytochemical compoun...
Effects of Different Stages of Training on the Intestinal Microbes of Yili Horses Analyzed Using Metagenomics. : The aim of this study was to investigate the effects of different stages of training on the intestinal microbial abundance of Yili horses. : Ten Yili horses, all aged 2 years old and weighing 305 ± 20 kg, were selected and divided into a training group and an untrained group. The training group performed riding training 6 days a week, and the untrained group moved freely in the activity circle every day. Fecal samples were collected on days 30 and 60, and the intestinal microorganisms were detected and analyzed using metagenomics. : Compared with the 30-day untrained group, the relative abu...
Comparative digestibility and gas production kinetics of Tifton 85 hay in donkeys and horses. This study aimed to verify whether donkeys of the Nordestino ecotype are more efficient than horses concerning apparent digestibility and gas production of Tifton 85 hay at different maturity stages, using the total feces collection method and the in vitro gas production technique. Four donkeys and four horses were used in a 2 × 2 factorial completely randomized design with two Equidae species and hay at two maturity stages (higher quality "Hay 1″ and lower quality "Hay 2″). No difference (P < 0,05) was found between the Equidae species for apparent nutrient digestibility of the Hay 1....
Evaluation of the Effects of Detomidine on Equine Myoelectrical Activity Using Electrointestinography. To evaluate the effects of detomidine on equine intestinal slow-wave activity and frequency distribution measured by electrointestinography (EIG). Methods: Prospective, experimental study. Methods: University teaching hospital. Methods: A convenience sample of twelve 7- to 21-year-old clinically normal horses. Methods: Horses were randomly assigned to saline control (four horses) or detomidine treatment (eight). After obtaining a 30-min baseline EIG, a saline or detomidine bolus was administered, followed by a constant rate infusion, and another EIG was recorded. Ultrasonographic examinations ...
Minimal disruption of equine gut microbiota by intravenous cephalothin treatment. In horses, the gut microbiota plays a critical role in maintaining intestinal homeostasis and overall health, but antimicrobial administration can disrupt its balance, resulting in dysbiosis, which can cause antibiotic-associated diarrhea. This study assessed the impact of intravenous cephalothin sodium administration on the equine gut microbiota by using microbial amplicon sequencing targeting the 16S-ITS-23S rRNA operon. Fecal samples from 39 clinically normal horses, 16 antibiotic-treated horses (cephalothin, n=5; minocycline, n=5; metronidazole, n=6, each administered for 5 days), and seve...
Characteristics and dynamic changes of gut microbiota in Mongolian horses and Guizhou horses. The gut microbial importance and its crucial roles in host digestion, immunity, and metabolism have received widely attention. Horses, especially indigenous varieties such as Mongolian horses (MGH) and Guizhou horses (GZH), have not received sufficient attention, and the characteristics of their gut microbiota are still unclear. For this purpose, we collected faecal samples from eight MGH and eight GZH to compare their gut microbial differences using amplicon sequencing. The results of alpha diversity analysis indicated that the gut bacterial diversity and gut fungal abundance in GZH were sign...
Prevalence of gastric ulcers in horses from the French Republican Guard cavalry regiment and association with plasma gamma-glutamyl transpeptidase activity. Equine gastric ulceration syndrome (EGUS) is a common condition, affecting both glandular (EGGD) and squamous (ESGD) mucosa of the stomach. It has a high prevalence, particularly in racehorses and sport horses, causing clinical signs from poor performance to colic. Gastroscopy, the reference standard diagnostic method, is expensive, prompting the search for alternative tests. Previous studies noted changes in blood markers, including elevated gamma-glutamyl transpeptidase (GGT) activity in ulcerated horses. This study aimed to report the prevalence of EGUS in sport horses and evaluate the asso...
Combining in vivo and in vitro approaches to investigate the effect of sainfoin on strongyle infection, immunity and large intestine ecosystem of horses. Sainfoin (Onobrychis viciifolia), a polyphenol-rich plant, has shown promising anti-parasitic properties in ruminants, but results in horses are fewer and inconsistent. The mechanisms of action involved are not fully understood and different factors may influence its anti-parasitic properties. Recently, it has been shown that the effect of sainfoin depends on the horse's diet. Indeed, the inclusion of dehydrated sainfoin pellets in a high starch diet limited the rate of increase in strongyle egg shedding over a short period of time (21 days). The objective of this study was to evaluate, in viv...
Effect of Management System on Fecal Microbiota in Arabian Horses: Preliminary Results. The gut microbiota plays a basic role in maintaining the psychophysical health and well-being of horses. Understanding the complex interactions among microbial communities in relation to age, management, and health is a topic of growing interest. The equine microbiota, given its complexity, is subject to variations caused by internal or external stressors that can lead to metabolic problems and pathologies, i.e., obesity and laminitis. The aim of this study was to characterize the fecal microbiota of 12 purebred Arabian horses and to compare the microbial communities in two distinct management...
Research Progress on Influencing Factors of Gastrointestinal Microbial Diversity in Equine. Microbiota in the gastrointestinal tract play a crucial role in nutrient digestion, health and so forth in equines. As the research attention on gut microbes has increased, several studies have investigated the composition of the gastrointestinal microbial flora in equines. This article reviews the effects of breed, age, intestinal site, nutritional management and diseases on the gastrointestinal microbiota of horses and donkeys, thus offering references for improving the gastrointestinal microecological environment in these animals and preventing and controlling disease occurrence in them.
Effects of vatinoxan on gastrointestinal motility, sedation, and antinociception during and after long-lasting detomidine infusion in horses. Sedation in horses is typically achieved using alpha-2 adrenoceptor agonists, although their use is associated with multiple side effects. A peripheral alpha-2 adrenoceptor antagonist, vatinoxan, can alleviate many of these. Objective: To evaluate the effects of vatinoxan infusion on gastrointestinal motility, sedation, and antinociception in horses sedated with detomidine infusion. Methods: Randomised, blinded cross-over in vivo experiments. Methods: Eight horses were given two 4-h infusions: detomidine (0.01 mg/kg + 0.015 mg/kg/h IV) (DET) and a combination of detomidine and vatinoxa...
Comparative analysis of gut microbiota in healthy and diarrheic foals. Diarrhea presents a substantial risk of high morbidity and mortality among foals. Although studies have shown connections between gut microbiota and several gastrointestinal diseases, there is still inadequate information on gut microbial alterations in foals during diarrhea. In this study, we conducted 16S rRNA and ITS gene amplicon sequencing to investigate gut bacterial and fungal differences between healthy and diarrheic foals. The results unveiled significant reductions in gut bacterial and fungal diversities among foals experiencing diarrhea, accompanied by notable shifts in the composit...
Thermal and non-thermal effects of microwave pretreatment on horse dung microbial communities used as inoculum for acidogenic fermentation. This study focuses on thermal and non-thermal effects of microwave pretreatment on horse dung as indigenous inoculum before xylose and wheat straw fermentation, emphasizing metabolite production and microbial community changes. Two horse dung microwave pretreatments (MW40°C and MW95°C) were compared with a conventional thermal pretreatment (Th95°C) and an unpretreated condition (Ctrl). Microwave heating pretreatment (MW95°C) leads to similar production as a conventional thermal pretreatment (Th95°C) for xylose and wheat straw fermentation while MW40°C treatment was similar to the control...
Microbiome analysis reveals dynamic changes of gut microbiota in Guizhou horse and Dutch Warmblood horses. In recent years, the importance of gut microbiota in digestive absorption, metabolism, and immunity has garnered increasing attention. China possess abundant horse breed resources, particularly Guizhou horses, which play vital roles in local agriculture, tourism, and transportation. Despite this, there is a lack of comparative studies on the gut microbiota of native Guizhou horses (GZH) and imported Dutch Warmblood horses (WH). To address this gap, fecal samples were collected from both GZH and WH, and 16S rRNA high-throughput sequencing was utilized to analyze the differences in their gut mic...
Isolation and molecular identification of Lactobacillaceae bacteria and Bifidobacterium from horse feces. The equine large intestine harbors a diverse array of symbiotic microorganisms. Disruptions in the gut microbiota can lead to various diseases in horses. Probiotics offer promising avenues for enhancing equine health and performance. However, commercial formulations lack robust scientific validation. This study aimed to isolate and identify Lactobacillaceae and Bifidobacterium spp. from horse feces to explore their potential as probiotics. Fecal samples from Thoroughbred horses were subjected to isolation procedures. Lactic acid-producing bacteria were isolated using specific media and identif...
Current understanding of insulin dysregulation and its relationship with carbohydrate and protein metabolism in horses. Insulin dysregulation (ID) is a common metabolic disorder in horses, characterized by hyperinsulinemia and/or peripheral insulin resistance. The critical role of hyperinsulinemia in endocrinopathic laminitis has driven research into the insulinotropic effects of dietary nutrients and the reciprocal impact of ID on nutrient metabolism. The relationship between ID and carbohydrate metabolism has been extensively studied; however, the effects of ID on protein metabolism in horses remain largely unexplored. This review begins with an overview of the importance of insulin in the regulation of muscl...
Medical treatment of sand enteropathy with psyllium, magnesium sulphate and paraffin oil in 54 Western Australian equids. Sand enteropathy describes the clinical signs attributed to accumulation of sand in the gastrointestinal tract. Psyllium combined with magnesium sulphate has been recommended for clearing intestinal sand, but this has only been evaluated in one population. The combination of these two agents with paraffin oil has not been investigated. Objective: To investigate the effectiveness of paraffin oil, psyllium and magnesium sulphate combined in clearing intestinal sand in horses diagnosed with sand enteropathy. Methods: Retrospective case series. Methods: Medical records of horses presenting for san...