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.
Murray MJ, Grodinsky C, Anderson CW, Radue PF, Schmidt GR.Gastroendoscopic examinations were performed on 187 horses, ranging from one to 24 years. Eighty-seven horses had clinical problems including chronic, recurrent colic for seven or more days (25), one or more episodes of colic within the previous seven days (13), or acute colic (10), diminished appetite (53), poor bodily condition (40), and/or chronic diarrhoea (9). One hundred horses that had no signs of gastrointestinal problems were examined as part of a gastroendoscopic survey. Lesions observed in the squamous fundus, squamous mucosa adjacent to the margo plicatus along the greater curvatur...
Morris DD, Moore JN.Serum immunoglobulin (Ig) titres to core lipopolysaccharide (LPS) were determined in 102 horses admitted to a university referral hospital during a 12-month period for evaluation of colic. Serum samples were collected again 10-14 days later from 84 of the horses. Titres to core LPS were quantitated by an indirect enzyme-linked immunosorbent assay (ELISA), utilising the J-5 mutant of Escherichia coli 0111:B4 as the solid-phase antigen. All horses had natural antibodies to core LPS at the time of admission and the titre was not affected significantly by age, sex or type of gastrointestinal disor...
Fessler JF, Bottoms GD, Coppoc GL, Gimarc S, Latshaw HS, Noble JK.Endotoxin (LPS) was quantitated in experimental subjects and in horses with naturally occurring gastrointestinal strangulation obstruction and/or septicaemic diseases to establish the fate of LPS and the clinical usefulness of the Limulus amoebocyte lysate (LAL) assay. The assay was validated for sensitivity (10 pg/ml), recovery (90 to 106 per cent), intra-assay precision (CV = 5.5 per cent) inter-assay precision (CV = 11 per cent), and stability of diluted, heat treated, frozen samples (at least 90 days). Plasma concentrations of LPS after sublethal (3 micrograms/kg) jugular or portal vein bo...
Ross MW, Bernard WV, Orsini PG, Ford TS.A 3-year-old Standardbred stallion was admitted for treatment of acute enterocolitis. The horse improved in response to empiric treatment, but subsequently developed ventral edema, scrotal abscessation, and severe laminitis. Improvement again was seen, but on day 29 of hospitalization, the horse developed rapid heart rate and signs of abdominal pain. Exploratory celiotomy revealed complete obstruction of the descending portion of the duodenum, 20 cm caudal to the duodenal sigmoidal flexure. Three-tier duodenojejunostomy and jejunojejunostomy were performed to bypass the duodenal obstruction.
Owen RA, Jagger DW, Quan-Taylor R.A caecocaecal intussusception in a pony and a caecocolic intussusception in a horse, both infected with Anoplocephala perfoliata, are described and the relevance of tapeworms in such intestinal disease of horses is reviewed.
Ragle CA, Meagher DM, Schrader JL, Honnas CM.A blind study was designed to determine if abdominal auscultation is an effective method for detecting the presence of intestinal sand. Fifteen horses divided into two groups were used in the study. There were seven horses in Group 1 and eight horses in Group 2. All horses were auscultated and determined to be free of sand sounds before initiation of Trial 1. Group 1 horses were given 4.2 g/kg body weight of sand via nasogastric tube using carboxymethylcellulose (CMC) as a suspending agent at 9.0 ml/kg body weight. Group 2 horses were given CMC only. Horses remained in the same group through a...
Morse CC, Richardson DW.An unusually large, pedunculated (20 cm long) mass arising the gastric pylorus which produced complete obstruction of the proximal duodenum and severe gastric distension was found in a 13-year old castrated male Arabian horse. The histological diagnosis was gastric hyperplastic polyp, which has not been reported previously in the horse. The clinico-pathological findings in this horse are compared with hyperplastic (inflammatory) gastric polyps of man.
Bonfig H.The purpose of this detailed description of the clinical examination of the colic patient is to arrive at a specific diagnosis. However, this is hardly ever possible, but the practitioner should be in the position to establish the suspicion of an intestinal obstruction or to rule out its presence during the course of the development. Single clinical findings should not be interpreted in isolation but in relation to one another, so that a false diagnosis is not made. All clinical findings should be documented, so that when repeated examinations are carried out, findings can be compared with one...
Rose J, Rose E.This article discusses some of the rationales for the medical management of colic during the initial treatment period. The issue of colic pain control and the masking of clinical signs that may indicate severe gastrointestinal disease is addressed. Therapeutic considerations related to dehydration, metabolic imbalances, hemostatic disorders, antimicrobial therapy, fecal consistency, gastrointestinal decompression, and regulation of intestinal motility are reviewed.
Hondalus MK, Lofstedt J.A 16-year-old pony with signs of intermittent abdominal pain was treated with phenylbutazone in excess of the recommended dosage. Endoscopy revealed ulceration of the esophagus, stomach, and proximal portion of small intestine. The pony developed diarrhea. Salmonella typhimurium was isolated from the blood and feces. Treatment included fluids, trimethoprim-sulfadiazine, sucralfate, and ranitidine hydrochloride. The diarrhea resolved, as did the gastrointestinal ulceration. This case was unusual because septicemia with salmonellosis is an uncommon finding in adult equids. Also, complications co...
Adams R, Koterba AM, Brown MP, Cudd TC, Baker WA.The medical records of 20 neonatal foals in which exploratory celiotomies were performed for gastrointestinal disease were reviewed. In all 20 foals, persistent pain and/or progressive abdominal distension were the primary clinical findings influencing the decision to operate. However, ancilliary laboratory data were important to the proper medical management of these foals during anaesthesia and following surgery. Surgical diagnoses of the 20 foals included ileus (nine foals; 45 per cent), small colon obstruction (five foals; 25 per cent), large colon displacement (three foals; 15 per cent), ...
Kersjes AW, Bras GE, Németh F, van der Velden MA, Firth EC.This retrospective study presents the results of surgical treatment of obstructive colic in horses operated in the last decade (1976-1985). The overall short-term recovery rate (i.e. discharged from hospital) was 51% of cases presented for surgery, and 68% of cases which were considered to be amenable to surgical therapy. For long-term results (6 months-8 years follow up) these percentages must be reduced by about 15% due to mortality after discharge. Special attention has been given to surgery of the ileum, which is often involved in strangulation or obturation, and accounts for about 26% of ...
Sweeney RW.Malassimilation should be suspected in horses with weight loss in spite of a good appetite. Malassimilation is usually confirmed with oral glucose or D-xylose absorption tests, whereas the oral lactose tolerance test can be used to evaluate lactase deficiency in foals. Once malassimilation is confirmed, other diagnostic tests such as abdominocentesis, rectal mucosal biopsy, or exploratory laparotomy with intestinal biopsies may determine the etiology of malassimilation.
Craig DR, Pankowski RL, Car BD, Hackett RP, Erb HN.Several surgical alternatives have been described for the management of cecal impaction in the horse, but none has met with consistently successful results. This study was done to evaluate a surgical bypass of the cecum by anastomosis of the ileum to the right ventral colon (ileocolostomy). A ventral midline celiotomy was performed on nine adult ponies (155-350 kg) and a mechanically stapled 10 cm side-to-side ileocolostomy was created. In five ponies a complete cecal bypass (CCB) was created by transecting the ileum distal to the anastomosis. In the other four, an incomplete cecal bypass (ICB...
Johnston JK, Morris DD.Sixty-eight horses with colic caused by small intestinal disease were allotted into 2 groups of 34 on the basis of recorded findings during exploratory celiotomy, necropsy, or response to medical treatment alone. Signalment, history, physical examination findings, and laboratory findings were compared between the group of horses with small intestinal obstruction and the group with duodenitis/proximal jejunitis. A significantly greater proportion of horses with duodenitis/proximal jejunitis were older than 2 years old (P less than 0.05). Differences in sex or breed distribution, or in seasonali...
Ross MW, Orsini JA, Ehnen SJ.A 5-year-old Thoroughbred gelding with recurrent cecal impaction refractory to medical management was treated with a side-to-side jejunocolic anastomosis. Cecal impaction did not recur after surgery. The horse gained weight and performed successfully for 14 months, but experienced three episodes of mild abdominal pain between 14 and 20 months after surgery. Mild cecal gas distention and firm ingesta in the colon were detected on rectal examination. The horse's feces remained soft after surgery, except during the colic episodes when dry, firm feces were passed.
Mackey VS, Pascoe JR, Peterson PR.Anastomotic leakage was noted to occur at the junction of the staple lines used to create the stoma during small intestine side-to-side anastomosis. The anastomosis was performed in a clinical equine patient by joining the lateral surfaces of the intestinal segments using a gastrointestinal anastomosis stapling instrument (GIA). The cause of this problem was investigated by performing six anastomoses in the jejunum of a single anesthetized adult horse using the GIA; three anastomoses were created by joining the antimesenteric edges of the bowel segments and three anastomoses were created by jo...
Simpson JW, Else RW.Methods are described for the endoscopic examination and biopsy of the gastrointestinal tract and liver of the dog, cat, ox and horse. The results of the examination of 41 biopsy samples are shown, followed by a discussion of the value of biopsy in the diagnosis of diseases of the digestive tract.
White NA, Tyler DE, Blackwell RB, Allen D.Records of 20 horses with small intestinal disease causing acute colic and affecting the proximal portion of the small intestine were examined retrospectively. The disease was characterized by severe to moderate pain, which was replaced by depression, fever, gastric reflux, slight distention of the affected small intestine, leukocytosis, and high concentrations of total protein in the peritoneal fluid. Grossly, the affected intestines were hemorrhagic and had yellow discoloration. Histopathologic findings included submucosal edema, neutrophilic infiltration of the submucosal and laminal propri...
Allen D, White NA, Tyler DE.Twenty horses with small intestinal obstructions requiring surgery were evaluated prospectively. Ten horses lived (group 1) and 10 died (group 2). Eight of the horses in group 1 had simple obstruction and 7 of the horses in group 2 had strangulation obstruction. There was a significant difference (P less than 0.001) between the mean intraluminal hydrostatic pressure in horses of groups 1 and 2 (6.3 cm H2O and 15 cm H2O, respectively). The mean peritoneal fluid protein concentration in horses of groups 1 and 2 (2.8 mg/dl and 5.4 mg/dl, respectively) also differed significantly between groups (P...
Livesey MA, Hulland TJ, Yovich JV.The research article discusses a rare case of colic in two horses, which was attributed to the existence of smooth muscle intestinal tumors. Introduction The article begins by explaining that […]
Moore JN, White NA, Trim CM, Garner HE.This study examined the effect of intraluminal oxygen administration on mucosal morphology following intestinal strangulation obstruction (ISO) in anesthetized ponies. The ISO was produced by ligation of the intestinal vasculature in 5 ponies for 50 minutes and 2 ponies for 90 minutes. Two ponies served as controls. Light and scanning electron microscopic examination of intestinal biopsy specimens revealed progressive mucosal degeneration following ISO in nontreated intestines, whereas high magnification scanning electron microscopic examination documented subtle evidence of microvilli disrupt...
Gray SN, Dechant JE, LeJeune SS, Nieto JE.To investigate postoperative hemoperitoneum in a population of horses that had surgery for colic. Methods: Retrospective case series. Methods: Horses (n = 23). Methods: Preoperative, intraoperative, and postoperative information was obtained from medical records (1985-2012) of horses with postoperative hemoperitoneum after emergency exploratory celiotomy. Pre-existing hemoperitoneum during surgery and nonsurgical hemoperitoneum were excluded. Results: Of 4520 horses that had emergency exploratory celiotomy for gastrointestinal disease, 23 horses met inclusion criteria; an incidence of 0.5%. Ho...
Hovda LR, Rose ML.A herd of pregnant horses exposed to hoary alyssum through ingested hay developed acute and severe gastrointestinal toxicity accompanied by intravascular hemolysis. Postmortem lesions were consistent with these signs. Three horses had late-term abortions.
Richardson LM, Gordon J, Davila C, Chamoun-Emanuelli AM, Zdyrski C, Whitfield-Cargile CM.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...
Loublier C, Taminiau B, Seidel L, Moula N, Tano C, Cesarini C, Costa M, Lecoq L, Daube G, Amory H.Faecal microbiota transplantation (FMT) and probiotics are used in equine practice. Understanding veterinarians' perceptions and practices is crucial for effective implementation. Objective: (1) Evaluate the prevalence, usage patterns and perceived effectiveness of probiotics and FMT among equine veterinarians in France and Belgium. (2) Assess their knowledge, practices and influencing factors across demographics and settings. (3) Explore links between FMT protocols and treatment satisfaction. Methods: Cross-sectional survey. Methods: An online survey collected demographic data and responses o...
Luthersson N, Harris PA, Parkin T, Þorgrímsdóttir ÚÝ, Bennet ED.It is unknown whether the high prevalence of Equine Squamous (ESGD) and Equine Glandular (EGGD) Gastric Disease in extensively grazed Icelandic horses in the autumn/winter is seasonally driven. Objective: To determine the prevalence of, and risk factors for, gastroscopically significant ESGD (ESGD:score of ≥2/4); gastroscopically severe ESGD (ESGD:score of ≥3/4) and gastroscopically significant EGGD (EGGD:score of ≥1/2) in extensively pasture-managed Icelandic horses at four timepoints. Methods: Prospective longitudinal cohort. Methods: Gastroscopy was undertaken in 80 Icelandic horses (...
Verberne LR, Mirck MH.The toxicity of parbendazole in different doses was investigated with 52 horses and 16 ponies, in twelve groups. Side effects observed with the anthelmintic were laxation (soft dung, diarrhoea), anorexia, and listlessness. The seriousness of these symptoms depended greatly on the dose used. Half the therapeutic dose of parbendazole (2.5 to 3.75 mg/kg) administered on two consecutive days led, as a rule, to only slight toxic symptoms and proved highly effective with regard to gastro-intestinal nematodes occurring in horses and ponies. The utilisation of "standard powders" (not commercially avai...
East LM, Savage CJ.Neoplasia of the equine gastrointestinal tract and abdominal organs occurs predominantly in geriatric horses, although lymphoma and hepatocellular carcinoma and a few other neoplasms can be found in young horses. This article discusses diagnostics that can be used in weight-loss situations, suspicious of neoplasia, as well as tumors themselves including clinical signs, diagnostic tools, histopathologic appearance, and management.
Beroza GA.A device and technique for intra-operative gastro-intestinal lavage was developed to remove ingesta from the stomach, large intestine and caecum of horses. The Gastro-Intestinal Lavage System (GILS) is composed of a nozzle connected to both water under pressure and suction. Water jets across an intake portal in the nozzle, breaks up food and debris within the nozzle and is evacuated under negative pressure into the aspirating tube which is connected to a collection drum. The GILS nozzle was introduced at the pelvic flexure through a sterile enterotomy cuff and plastic sleeve. Water was first a...
Duran MC, Starrak G, Dickinson R, Montgomery J.After physical examination, ultrasonographic evaluation of thorax and abdomen, and peritoneal fluid analysis, gastrointestinal neoplasia with suspected diffuse peritoneal metastasis was diagnosed in a 17-year-old Arabian gelding. The owner elected euthanasia and declined postmortem examination. Immunocytochemistry analysis of the peritoneal fluid resulted in a diagnosis of B-cell lymphoma. Immunocytochimie du liquide péritonéal utilisée pour le diagnostic d’un cas possible de lymphome gastro-intestinal à cellules B. Après un examen physique, une évaluation échographique du thorax et d...
Honoré ML, Pihl TH, Busk-Anderson TM, Flintrup LL, Nielsen LN.D-dimer has value as a marker of thrombosis in critically ill horses and can provide additional information about prognosis. However, there are currently no equine species-specific d-dimer assays available, nor has there been any formal investigation of the applicability of human d-dimer assays in horses, so it is unknown, which assay performs best in this species. The aim of this study was therefore to evaluate and compare two human d-dimer assays for their applicability in horses. The study included four groups of horses: clinically healthy horses, horses with gastrointestinal (GI) disease a...
Martín-Cuervo M, Aguirre CN, Gracia LA, Barrera R, Ezquerra LJ, Martinez-Subiela S, Cerón JJ.Point-of-care (POC) systems for the joint measurement of Troponin and D-dimers have not been studied in horses. The aim of this study was to perform the validation of a POC system (AQT90 FLEX) for the measurement of cardiac troponin I (cTnI) and D-dimers in the serum of horses with gastrointestinal diseases. The main objective was to evaluate whether or not this system can distinguish healthy animals from diseased animals. A sample of 33 horses was included in the study: control group (n = 10) and horses with gastrointestinal disorders (n = 21), which were classified according to their outco...
Asakawa MG, Jamieson CA, David F, Johnson JP, Mehmood W, Oikawa MA.A 5-year-old Arabian broodmare with acute colic was diagnosed with lymphocytic ganglioneuritis of the coeliac-mesenteric ganglia and lymphocytic‒plasmacytic enterocolitis resembling inflammatory bowel disease. No significant pathogens were identified by aerobic culture or histopathological examination. The ganglia were multifocally infiltrated with small lymphocytes that were immunopositive for CD3 and negative for CD20 and CD79a antigens, indicating CD3+ T-lymphocyte-mediated coeliac-mesenteric ganglioneuritis. The findings suggest immune-mediated inflammatory bowel disease resulting in dis...
Sweeney RW.Malassimilation should be suspected in horses with weight loss in spite of a good appetite. Malassimilation is usually confirmed with oral glucose or D-xylose absorption tests, whereas the oral lactose tolerance test can be used to evaluate lactase deficiency in foals. Once malassimilation is confirmed, other diagnostic tests such as abdominocentesis, rectal mucosal biopsy, or exploratory laparotomy with intestinal biopsies may determine the etiology of malassimilation.
Simpson JW, Else RW.Methods are described for the endoscopic examination and biopsy of the gastrointestinal tract and liver of the dog, cat, ox and horse. The results of the examination of 41 biopsy samples are shown, followed by a discussion of the value of biopsy in the diagnosis of diseases of the digestive tract.
Hubbell JA, Muir WW.Clinical examination of the equine patient with acute abdominal pain should identify the affected body system and yield a provisional diagnosis. Determination of signalment, history, physical examination, and basic laboratory tests should assist in classification of the gastrointestinal disorder and direct the therapeutic plan. Determination of the definitive diagnosis of abdominal pain based on clinical examination is not crucial. For a successful outcome, efforts should be directed toward early recognition of the need for surgery and treatment of cardiovascular compromise in horses with seve...
Hanson PD, Bartz TA, Stone WC, Darien BJ, Markel MD.A modification of the Roux-en-Y anastomosis procedure was used to bypass a pyloroduodenal mass in a 12-year-old Arabian stallion. Clinical signs had consisted of a 4-week progression of ventral and hind limb edema, hypoproteinemia, fecal occult blood, intermittent abdominal pain, weight loss, and gastric reflux. On exploratory celiotomy, an obstructive mass was found in the pylorus and proximal portion of the duodenum. Gastrojejunostomy and duodenojejunostomy were performed by use of stapled side-to-side anastomosis techniques. Inaccessibility of the obstructed pyloric region prevented resecti...
Beroza GA, Donawick WJ, Topkis VA.A technique of nasoduodenal (N-D) intubation and intestinal decompression was developed and used in the horse to explore the prevention of gastric and intestinal distention after abdominal surgical operation. Three styles of tubes (2 single-lumen tubes and 1 double-lumen tube) were positioned in the duodenum of 12 mature horses (10 experimental and 2 clinical) during laparotomy (without enterotomy), and an iatrogenic occlusion at the small intestine was created and later released in the 10 experimental horses. The 2 clinical horses had an exploratory laparotomy to correct a natural obstruction...
Brabon A, Labens R, Ramachandran A, Dart AJ, Dowling BA.Four adult horses with histories of moderate abdominal pain and inappetence were diagnosed with delayed gastric emptying and gastric impaction attributed to pyloroduodenal obstruction (three cases) or duodenitis (one case). A stapled side-to-side gastrojejunostomy was performed on all horses. Two horses returned to work and survived ≥3 years. One horse was euthanased 6 months post-surgery due to recurrent abdominal pain, and one was found dead 5 months postsurgery after an unattended foaling.
Mersich I, Wilkins PA.Gastrointestinal neoplasia is uncommon in horses. Clinical signs can be vague and advanced testing, including biopsy, exploratory surgery, and/or advanced imaging may be required for diagnosis. Prognosis varies by location, organ involved and is frequently poor to grave.
