Gastrointestinal diseases in horses encompass a range of disorders affecting the digestive tract, from the mouth to the intestines. These conditions can include colic, gastric ulcers, enteritis, and colitis, among others. The gastrointestinal system in horses is complex and sensitive, making it susceptible to various disruptions. Factors such as diet, management practices, and environmental stressors can influence the onset and progression of these diseases. Understanding the pathophysiology, diagnosis, and treatment options for gastrointestinal diseases is essential for maintaining equine health and welfare. This page aggregates peer-reviewed research studies and scholarly articles that explore the causes, clinical presentations, and management strategies for gastrointestinal diseases in horses.
Pearson H, Pinsent PJ, Denny HR, Waterman A.The indications for laparotomy in 140 horses are analysed, with particular emphasis on the operative or autopsy findings in 82 cases of colic. In cases of exploratory laparotomy, the overall recovery rate was only 28 per cent but 48 of the 82 animals were considered to have inoperable lesions. The recovery rate and causes of death for each indication are briefly reviewed.
Donawick WJ.The horse with an abdominal crisis caused by acute gastro-intestinal tract obstruction develops hypovolaemia, haemoconcentration, electrolyte depletion, metabolic acidosis and shock. During preparation for operation, treatment with fluids, antibiotics and bicarbonate will impede metabolic imbalance. Stomach decompression may slow the passage of sodium, water and potassium to the gut lumen, reduce pain and minimize the risk of stomach rupture. Selected laboratory determinations and the monitoring of arterial and venous pressures will provide a measure of security, and serve as a guide to replac...
Misdorp W.A pathological study of 333 tumours of farm animals in the Netherlands is presented. Most of the tumours (224) were collected at the Amsterdam abattoir over a period of five consecutive years. The incidence of different types of the tumours is compared with figures compiled in the U.S.A. Tumours in cattle and pigs were less frequent in the Amsterdam material than in the U.S.A., but the incidence in horses and sheep was higher than reported elsewhere. Tumours of the jejunum, the ovaries and to a lesser extent of the heart were more frequent, but those of the skin and male genital organs were le...
Littlejohn A.The mortality following operations for intestinal obstructions in horses decreased from 80 per cent during the period 1849-1913 to 22 per cent during the period 1934-1964. Mortality following operations for high intestinal obstructions was greater than for low intestinal obstructions, and the mortality following operations for strangulating obstructions was more than twice as great as the mortality following simple obstructions. The most frequent cause of death following operations was failure to correct the causal condition, or subsequent impaction.
The anaesthesia techniques most frequently...
Vinijkumthorn R, Prapaiwan N, Chotikaprakal T, Prompiram P, Phaonakrop N, Roytrakul S, Tesena P.Phenylbutazone (PBZ) can potentially induce gastrointestinal ulceration, and early detection of PBZ-induced gastroenteropathy will be useful for the diagnosis, treatment, and prevention of PBZ toxicity. Objective: To identify putative proteins associated with equine gastric ulcer syndrome after clinical dose (4.4 mg/kg) administration of PBZ by proteomic study. Methods: In vivo experiments. Methods: Proteomic analysis using LC-MS/MS compared protein expression in serum and faeces of seven PBZ-treated horses with seven placebo-treated controls, and a novel putative biomarker was validated via...
Gamage C, Holl W, Parreño V, Thieulent CJ, Balasuriya UBR, Vissani MA, Barrandeguy ME, Carossino M.Group A rotavirus (RVA) infections are a leading cause of neonatal diarrhoea in foals. Neonatal mice could serve as a useful tool to study the pathogenesis of equine RVA (ERVA) as well as a preclinical model for assessment of vaccine efficacy. This study aimed to comparatively evaluate the clinical, virological and pathological features of ERVA G3P[12] and G14P[12] infection in neonatal mice and compare them with porcine OSU G5P[7] and bovine UK G6P[5] RVA reference strains. Neonatal mice orally inoculated with equine, bovine and porcine RVA developed short-lived diarrhoea at variable rates, G...
Agrícola R, Ribeiro G, Borges J, Carvalho L, Roquet I, Carvalho LM, Prazeres J.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...
Faircloth J, Fielding L, Epstein K, Crabtree N, Mochal C, Magdesian G, Major D.To describe the clinical presentation of horses with synchronous diaphragmatic flutter (SDF) and identify clinical and laboratory variables associated with survival. Methods: Retrospective study from January 2004 to September 2022. Methods: Five large animal referral hospitals in the United States. Methods: Thirty-seven horses of various breeds and ages presenting with clinical signs of SDF, excluding animals participating in an endurance competition. All horses were >1 year of age. Methods: None. Results: Variables recorded and analyzed included signalment, clinical and laboratory data, trea...
Busechian S, Di Salvo A, Orvieto S, Rueca F, Villella C, Sollevanti G, Pieramati C, Nisi I, Della Rocca G.Equine Gastric Ulcer Syndrome (EGUS) is a worldwide disease described in different categories of animals. A causal relationship between exercise and EGUS has been suggested, attributed to stress as well as physiological changes in the position of abdominal organs, especially during trot and gallop. EGUS can influence athletic fitness, as has been described in various papers on racehorses. The aim of this work was to determine if gastric ulcer healing is associated with changes in selected fitness parameters (i.e., speed, heart rate during exercise and recovery, stride length and frequency) in ...
Castillo JDCR, Forte L, Elghandour MMMY, Maggiolino A, De Palo P, Ponce-Covarrubias JL, Salem AZM.Parasitic infections remain a major constraint to equine health and performance, and the worldwide rise of anthelmintic resistance is forcing a shift toward integrated parasite management and new complementary tools. Caesalpinia coriaria (Divi-divi) pods are exceptionally rich in tannins and have been proposed as a potential source of antiparasitic phytochemicals. This review summarizes the current evidence on C. coriaria, focusing on its relevance to equine gastrointestinal helminths. Most available data come from in vitro screening against ruminant nematode models (mainly Haemonchus contortu...
Díaz-Alvarado T, Alcala-Canto Y, Elghandour MMMY, Salem MZM, Mariezcurrena-Berasain MD, Salem AZM.Gastrointestinal endoparasitic diseases, particularly those caused by some strongyles, represent one of the main health challenges in equine production. The prolonged use of synthetic anthelmintics has led to the development of resistance, which has prompted the search for more sustainable therapeutic alternatives. However, plant extracts rich in secondary metabolites are emerging as a promising option. Objective: The objective of this study was to evaluate the in vitro anthelmintic activity of aqueous extracts and bioactive compounds (total phenols and saponins) from Azadirachta indica and Cn...
Hodgson E, Romano TR, Stewart A, Bond S, Wise J.The pathogenesis of gastric ulceration is not well understood in foals, and its relationship with gastric acidity requires further investigation. A wireless capsule, designed for intraesophageal pH monitoring in humans, was adapted to measure intragastric pH in adult horses. Objective: To (1) determine the feasibility of wireless intragastric pH measurement in foals; (2) determine capsule attachment duration; and (3) describe the intragastric pH profiles recorded. Methods: Eight healthy foals aged 24-98 days. Methods: Prospective interventional study. Capsules were attached to the glandular g...
Cabaret J, Guerrero Molina C, Martínez-Ortiz-de Montellano C, Alcala Canto Y.Faecal egg counts (FECs) are used to assess the intensity of gastrointestinal nematode (GIN) infections in herbivores. FEC distribution is aggregated, meaning that approximately 20% of animals harbour 80% of infections. In times of escalating anthelmintic resistance, it may be necessary to restrict treatment to the animals with the heaviest infections. This strategy is called targeted selective treatment (TST) and is relevant to GIN, for example. The difficulty lies in identifying which animals to treat. One solution is to select potentially at-risk animals based on age (for example, treating ...
Burns JJ, Stull J, John E, Doyle A.For horses presenting for colic to a referral hospital in Atlantic Canada, we aimed to describe clinical findings, diagnosis, treatment, and outcome for draft breeds; identify associations between clinical findings, diagnosis, treatment, and outcome for draft compared to nondraft breeds; and identify the overall impact of draft breed on mortality. Unassigned: A retrospective review of equine colic cases presenting to the Atlantic Veterinary College (2004 to 2023). Logistic regression models were used to assess associations between parameters and draft breed and mortality. Unassigned: A total o...
Willette J, Guinn A, Munsterman A.Impactions of the jejunum are rarely described in the literature. The current case series describes six cases of adult horses with jejunal impactions with feed material diagnosed by exploratory celiotomy. Horses underwent exploratory celiotomy based off of their degree of pain despite medical management and concerns for a primary strangulating small intestinal lesion. All jejunal impactions were relieved via manual decompression of the impaction into the cecum. None of the cases underwent a resection or anastomosis at the site of impaction. All horses were treated with gastroprotectants (omepr...
Neira-Egea P, Alamar Malvoisin C, de la Cuesta-Torrado M, Bautista-Erler C, Vitale V, Jolly S, Cesarini C. spp. are ubiquitous yeasts that are part of most mammals' microbiota and can become opportunistic pathogens under predisposing conditions. Interestingly, recent studies in human medicine report an increased abundance of spp. in association with inflammatory bowel disease (IBD). Gastrointestinal candidiasis has been primarily reported in neonatal foals, but not in adult horses. The aim of this study is to describe the morphological, histopathological, and microbiological features of gastric lesions associated with infiltration in five horses referred to two tertiary hospitals for different r...
Porter MM, Davis DJ, McAdams ZL, Townsend KS, Martin LM, Wilhite C, Johnson PJ, Ericsson AC.Fecal water syndrome (FWS) in horses is characterized by two-phase defecation, including both solid and liquid phases. While satisfactory explanations for FWS are unavailable, bacterial dysbiosis has been suggested as a contributing or causative factor. The objectives of this study were to determine whether fecal bacterial dysbiosis is associated with FWS in horses in the midwestern USA. Fecal samples were collected from horses with FWS and from unaffected horses at the same location. In total, 16S rRNA amplicon libraries produced from fecal bacterial DNA were sequenced using the Illumina sequ...
Crosby CE, O'Connor A, Munsterman AS.Colic is a significant source of morbidity and mortality in horses, and no single biomarker can distinguish surgical from medical colic or predict mortality. Alactic base excess (ABE) has shown an association with mortality and renal insufficiency in humans but has not been evaluated in veterinary species. The purpose of this study was to determine the value of ABE as a diagnostic tool for horses treated for gastrointestinal disease. Unassigned: This retrospective case series evaluated horses admitted for acute gastrointestinal disease over a 5-year period (2019-2024). Signalment, physical exa...
Raidal SL, Freccero F, Carstens A, Weaver S, Padalino B.Transportation of horses has been associated with colic and changes to the gastrointestinal microbiome. Percutaneous abdominal ultrasonography using wireless, point-of-care transducers can be used to assess gastrointestinal motility in field settings. Unassigned: Characterization of intestinal motility and salivary cortisol responses of horses completing commercial transportation of 10-12h. Unassigned: Prospective observational study of 30 horses with diverse signalment and transport histories. Clinical parameters, sonographic assessment of intestinal motility and saliva samples, were collecte...
Paganelli GC, Schott HC.Small intestinal (SI) distension and gastric reflux (GR) are common in horses with mechanical and functional ileus. Removal of GR results in fluid/ion losses. Objective: 1) Determine the capacity of healthy SI; 2) measure ion concentrations in normal SI fluid, GR, or fluid from SI undergoing resection. The authors hypothesized that Na and Cl concentrations would be lower and higher, respectively, in GR as compared to SI fluid from healthy horses, while there would be little difference in K concentration. Methods: Observational study: two to 15 meters of SI from 15 horses were distended with wa...
Kuzmina TA, Königová A, Burcáková L, Syrota Y, Babják M, Várady M.Strongylids and parascarids are the most widespread equine parasites worldwide; however, up-to-date data from Slovakia remain limited. This work bridges that gap by examining the prevalence and level of gastrointestinal helminth infections in Slovak horses. In the study, 392 fecal samples from horses on 24 farms were analyzed using the McMaster method with a sensitivity of 50 eggs per gram (EPG) for detecting nematode eggs and a double-centrifugation/combined sedimentation-flotation protocol for detecting Anoplocephala spp. eggs. Information on the age and breed of horses, management condition...
Yano R, Moriyama T, Arai H, Scheftgen AJ, Suen G, Nishida T, Handa M, Fukuma N.Colic, a major gastrointestinal disease in horses, has a high recurrence rate and can lead to surgery or fatal outcomes, highlighting the need for effective prevention measures. Disruption of the microbiome is a multifaceted problem and can occur from a variety of factors, such as high-concentrate diets, which can then potentially cause colic. However, individual variation in the incidence of colic can occur when under identical management practices. The aim of this study was to characterize the fecal bacterial composition of Japanese draft horses with and without a history of colic in the pas...
Freeman DE, Smith B, Bauck AG, Denagamage T, Moyer EK, Chanutin S.To develop a modified stapled (MS) jejunocecostomy (JC) in healthy horses. Methods: In vivo experimental study. Methods: Six healthy adult horses underwent ventral midline celiotomy, a jejunal resection, and an MS. Methods: Time to complete anastomosis and anastomotic length at necropsy were recorded. Horses were assessed by physical examination every 6 h for 5 days after surgery, then once daily until euthanasia at 7 days. A group of seven horses that had a stapled side-to-side JC and were euthanized 28 days postoperatively was used as an historical control (SS). Results: All MS horse...
Frippiat T, Bonhomme M, Dyson S, Votion DM.Equine gastric ulcer syndrome (EGUS) adversely affects the health, welfare, and performance of sports horses, requiring gastroscopy for definitive diagnosis. Owners frequently consider girth aversion as highly suggestive of EGUS. Objective: To evaluate whether owner-reported clinical signs or fecal occult blood tests (FOBTs) can help identify horses needing gastroscopy for EGUS diagnosis or monitoring treatment, thereby reducing unnecessary procedures in unaffected horses. Methods: Eighty competition dressage horses referred by veterinarians for EGUS evaluation. Methods: Case-control study in...
Hobbs KJ, Ludwig EK, Martin EM, Bayless R, Bauck AG, Freeman DE, Gonzalez LM.To determine if blood and peritoneal fluid levels of syndecan-1, heparan sulfate, and hyaluronan are elevated in horses with small intestinal disease compared to healthy counterparts. Unassigned: 61 horses were categorized into control (n = 20), inflammatory (11), and strangulating (30) groups. Paired peritoneal fluid and blood samples were obtained from each group from December 2016 through December 2024 and analyzed via equine-validated ELISAs for syndecan-1, heparan sulfate, and hyaluronan concentrations. Patient survival to discharge was recorded for all groups. Immunofluorescence staining...
Abbas G, Nielsen MK, E-Hage C, Ghafar A, Beveridge I, Bauquier J, Beasley A, Wilkes EJA, Carrigan P, Cudmore L, Jacobson C, Hughes KJ, Jabbar A.Over the past 25 years, significant progress has been made in understanding and managing equine gastrointestinal parasites in the Asia-Pacific region, particularly in Australia and New Zealand. This review synthesises current knowledge of the epidemiology, diagnostic methods, anthelmintic resistance (AR), and control strategies for major equine intestinal parasites, including cyathostomins, Parascaris spp., Anoplocephala perfoliata, and Strongyloides westeri. Recent studies highlight substantial regional variation in parasite prevalence, egg shedding and cyathostomin population composition, sh...
Klinck M, Lovett A, Sykes B.Equine gastric ulcer syndrome (EGUS) refers to mucosal gastric disease in horses, including equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD), which present as two distinct disease entities differing in pathophysiology and approach to disease management. Both diseases are a source of pain in affected horses, partly explaining why EGUS continues to receive substantial attention in the equine medical, welfare and equitation research sectors. There is a complex interplay between EGUS and a variety of physical and psychological stressors. Horses with EGUS are often...
Haywood LMB, Clark A, Hause B, Sheahan B.Many cases of equine enterocolitis are suspected to be infectious in nature, but no pathogen is identified in many cases. Objective: Perform next-generation sequencing on faeces collected from cases of equine enterocolitis for the presence of novel viruses and determine if an identified novel virus is associated with cases of equine enterocolitis. Methods: Retrospective cohort study. Methods: Next generation sequencing was performed targeting viral genomes from n = 13 pooled faecal samples (n = 5 horses/pool) with enterocolitis. Subsequent qPCR was performed targeting the highly conser...
Alonso FH, Hallum J, Arndt S.We report here a case of lipid-rich abdominal fluid in a 31-y-old Arabian gelding with acute colic. Abdominocentesis yielded opaque, yellow-to-orange peritoneal fluid with an elevated triglyceride concentration (42 g/L, RI: <0.10 g/L; fluid:serum triglyceride ratio 11.4, RI: <1.0). A second abdominocentesis performed 3 d later revealed clear fluid, suggesting transient chyloabdomen. Despite medical management, the horse developed respiratory distress secondary to pharyngeal edema and was euthanized. Autopsy identified a large omental lipoma and severe ulcerative gastritis, but no effusion....
Pekkarinen HM, Simola U, Niinistö KE, Syrjä PES.Equine inflammatory bowel disease (IBD) is challenging to diagnose and treat. Although the number of horses examined due to suspicion of IBD is increasing, the different treatments in clinical patients and their responses are not well documented. We sought to characterize the demography, signs, clinical and rectal biopsy findings, and treatment response in Finnish horses suspected to have IBD. Horses undergoing clinical examination due to suspected IBD in 2022 and with a good-quality rectal biopsy were selected for the study. General information, signs, clinical and histological findings, and ...
McAdams ZL, Campbell EJ, Dorfmeyer RA, Turner G, Shaffer S, Ford T, Lawson J, Terry J, Raju M, Coghill L, Cresci L, Lascola K, Pridgen T....Horses and other equids are reliant on the gut microbiome for health, and studies have reported associations between certain clinical conditions and features of the fecal microbiome. However, research to date on the equine fecal microbiome has often relied on small sample sizes collected from single and relatively localized geographic regions. Previous work also largely employs single timepoint analyses, or horses selected based on limited health criteria. Results: To address these limitations and expand our understanding of the core microbiome in health, and the changes associated with advers...
Pereira GF, Blimbliem MCH, Machado ALPR, Abdala JBR, Nogueira GM, Toma HS, de Carvalho TF, Delfiol DJZ.Arsenic poisoning in horses is rarely reported in the literature. However, arsenic compounds can be present in rodenticides, pesticides, and herbicides, representing a potential source of accidental exposure for horses. Objective: To describe the epidemiological, clinical, and laboratory findings from a herd of 31 horses exposed to pasture treated with an overdose of sodium hydrogen methylarsonate, and to compare results in a group of horses exposed to the recommended dosage of the same product. Methods: Observational field study. Methods: Thirty-one horses were evaluated after grazing on a pa...
Schank N, Cottone A, Wulf M, Seiter K, Thomas B, Miller LMJ, Anderson SL, Sahyoun A, Abidi AH, Kassan M, Verma A.Equine colic remains a prevalent and potentially life-threatening condition with multifactorial origins, including dietary imbalances, stress, and microbial dysbiosis. Central to equine gut health is the production of short-chain fatty acids (SCFAs), primarily acetate, propionate, and butyrate, generated through microbial fermentation of dietary fibers in the hindgut. These metabolites not only serve as vital energy sources but also play crucial roles in maintaining intestinal barrier integrity, modulating motility, and suppressing inflammation. This review explores the role of SCFAs in equine...
