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.
White NA, Dabareiner RM.Impactions have been reported in the stomach and all segments of the intestine. Impactions predominately occur just oral to sites of intestinal narrowing or active pacemakers. The most common sites of impaction are in the ileum, the cecum, and the large colon pelvic flexure. The treatment of gastrointestinal impactions depends on the segment affected and the amount of bowel damage which has occurred from distension. Many impactions respond to appropriate administration of analgesics, cathartics, and oral or intravenous fluids. The prognosis for impactions treated medically is better than for t...
Orsini JA.Foals are good candidates for abdominal surgery because their smaller size permits a more complete abdominal exploration and frequently definitive procedures in many cases. The use of rectal examination is replaced with alternative diagnostic modalities such as barium contrast radiography and ultrasonography. With the advancements in these technologies they can distinguish common gastrointestinal lesions and, in most cases, provide sufficient information to guide surgical intervention. The unique aspects of diagnosis and surgical management of gastrointestinal disorders of the foal are discuss...
Ragle CA, Southwood LL, Galuppo LD, Howlett MR.Two mares were referred for evaluation after dystocia and rectal prolapse. Diagnostic laparoscopy, performed while the horses were standing, was used to evaluate the condition of the distal portion of the colon, rectum, uterus, and mesocolon. In both horses, laparoscopic observation revealed tears in the mesocolon of the descending colon. Exploration from the left or right flank was adequate. Because of the poor prognosis associated with the findings, euthanasia was elected at completion of laparoscopy. Tears in the mesocolon are not easily detected by use of traditional tests. Laparoscopy pro...
Schusser GE, White NA.To determine the number of myenteric plexuses and neurons in the large colon of clinically normal horses and whether the number was decreased in the large colon of horses with colon disease. Methods: Prospective study. Methods: Colon samples from 15 clinically normal horses and 31 horses with colon disease. Methods: Samples were obtained, fixed, and stained with H&E. The number of myenteric plexuses and neurons and longitudinal muscle thickness were determined in each segment of colon for clinically normal horses. Counts for segments were compared with each other and with counts in the sam...
Murray MJ, Eichorn ES.To determine the effect of decreasing gastric acidity in a feed-deprivation protocol on induction of gastric ulcers, and to determine whether stall confinement may be a factor contributing to gastric ulceration in horses. Methods: 8 adult horses, 4 geldings and 4 mares, 3 to 8 years old, and 7 adult horses, 5 geldings and 2 mares, 4 to 11 years old. Methods: Gastric ulceration was induced in horses by alternating 24-hour periods of feed deprivation and ad libitum access to hay, for a total of 96 hours' feed deprivation. This protocol was repeated with the horses receiving the histamine type-2 ...
Barton MH, Collatos C, Moore JN.Peritoneal fluid was collected aseptically from 30 healthy adult horses and 115 horses with acute gastrointestinal disease and supernatant was separated from cells by centrifugation followed by freezing until assayed for endotoxin and tumour necrosis factor activity. Peritoneal macrophages obtained from healthy horses were incubated in vitro for 3, 6, 12 or 24 h in the absence (media control) or presence of Escherichia coli 055:B5 endotoxin (final concentrations of 1, 10, 100 or 1000 ng/ml). Macrophages obtained from horses with acute gastrointestinal disease were incubated for 12 h in the abs...
Hanson RR, Schumacher J, Humburg J, Dunkerley SC.To evaluate clinical and laboratory findings for horses treated medically for ileal impactions. Methods: Retrospective case series. Methods: 10 horses with primary ileal impaction that were treated successfully with medical treatment alone. Methods: Medical records were reviewed for all horses with naturally developing ileal impaction seen at our hospital between 1990 and 1994. Results: Transrectal palpation revealed an impaction in the midabdominal area in all horses. Generalized distention of the small intestine was evident in 6 horses, whereas 4 horses were examined early in the course of t...
Moore RM, Hance SR, Hardy J, Moore BR, Embertson RM, Constable PD.Colonic luminal pressure (median, range) measured during ventral midline celiotomy in 69 horses with strangulating obstruction (SO) of the large colon (SO; > or = 270 degrees large colon volvulus; 27 cm H2O: 2 to 80 cm H2O) was greater (P = .0023) than that measured in 37 horses with nonstrangulating obstruction (NSO) of the large colon (NSO; < or = 180 degrees volvulus or a nonstrangulating displacement; 18 cm H2O; 6 to 46 cm H2O). Sixty-five percent (45 of 69) of horses with SO and all horses with NSO survived. Survival analysis was restricted to 59 horses with large-colon SO that survived t...
Wernery U, Nothelfer HB, Böhnel H, Collins WR.An acute outbreak of a C. perfringens Type C enterotoxemia in a polo club killed 8 polo ponies in less than 24 hours. Hay with a massive fungal contamination (Aspergillus and Fusarium sp.) is suspected to have triggered the enterotoxemia. Our cases show numerous similarities with the previously reported cases of EIC. However, acute toxic tubulonephrosis in the necropsied horses and longstanding elevation of AST and gamma GT-levels in survivors is unique in our cases.
Steiner A, Roussel AJ.Hypodynamic gastrointestinal disorders in horses and cattle that are thought to benefit from treatment with drugs restoring and coordinating gastrointestinal motility include postoperative ileus and large colon impaction in the horse and displacement of the abomasum and dilatation of the cecum in cattle. Important physiologic, pathophysiologic and pharmacologic mechanisms involved in the intrinsic control of gastrointestinal motility include cholinergic, adrenergic, dopaminergic, serotoninergic, and opioid-mediated pathways. Preliminary results suggest that cisapride, acting on 5-Hydroxytrypta...
Slater MR, Hood DM, Carter GK.A descriptive and matched case-control study of laminitis was conducted in 7 private practices and at the Texas Veterinary Medical Centre (TVMC) between May 1992 and July 1993. Out of 108 horses with laminitis, 19 acute (49%) and 20 chronic (51%) cases were seen in private practice and 16 acute (23%) and 53 (77%) cases at the TVMC. Gastrointestinal disease was the most common problem in 19/35 horses (54%), occurring just prior to the onset of acute laminitis in all hospitals. Among all horses in the study, most commonly used drugs were phenylbutazone (68%), acepromazine (34%), dimethyl sulphox...
Collatos C, Barton MH, Prasse KW, Moore JN.Components of the coagulation and fibrinolytic cascades, prothrombin and activated partial thromboplastin times, endotoxin activity, and albumin concentration were measured in blood and peritoneal fluid from 20 healthy horses and from 153 horses with acute gastrointestinal tract diseases at admission. Overall, 77% (117/153) of affected horses survived to discharge from the hospital, and 85% (82/97) of horses discharged were reported to be normal 9 to 14 months later. Significant differences in hemostatic factors were more common in peritoneal fluid than in blood. Tissue plasminogen activator, ...
Ceccarelli P, Pedini V, Gargiulo AM.The presence and distribution of serotonin-containing cells in the gastroenteric tract of horses have been investigated. The enterochromaffin (EC) cells have been identified using immunostaining procedures at both light and electron microscopic level. The EC cells were very numerous in the pyloric gland region, were only few in the duodenum but were absolutely lacking from the more distal portions of the intestine.
Mueller PO, Hunt RJ, Allen D, Parks AH, Hay WP.The effect of intraperitoneal sodium carboxymethylcellulose (SCMC) administration on clinical outcome and survival was evaluated in horses undergoing exploratory celiotomy for acute gastrointestinal disease. Comparison of variables was made retrospectively between 44 horses that had SCMC and 92 horses (controls) not treated with SCMC. Mean age, body weight, heart rate, packed cell volume and plasma total protein of horses at admission, and convalescent period were not significantly different between control and SCMC groups. No significant differences were noted between control horses and SCMC ...
Dabareiner RM, White NA.Medical records from all horses with large colon impaction admitted between 1985 and 1991 were examined. Large colon impaction was diagnosed in 147 of 1,100 (13.4%) horses with colic. One hundred thirty horses were admitted for further evaluation of acute onset of abdominal pain after having been examined and treated by referring veterinarians, and 17 horses that were hospitalized for unrelated medical problems developed large colon impaction. Female horses (92/147; 62.6%) were more commonly affected than males. The age ranged from 1 to 29 years (median, 7.1 years). Mean duration of clinical s...
Schumacher J, Mullen J, Shelby R, Lenz S, Ruffin DC, Kemppainen BW.Duodenitis/proximal jejunitis syndrome (DPJ) is a small intestinal disease of horses that is associated with depression and copious gastric reflux. Since an infectious cause for DPJ remains unsubstantiated, these studies were designed to investigate the possible role of Fusarium moniliforme toxins in this disease. Fusarium moniliforme was isolated by culturing 2 samples of feed that had been fed to horses with clinical signs of DPJ. These isolates (AU 2/3) were subsequently grown concurrently on autoclaved corn and their toxicity evaluated in a feeding trial utilizing horses. Isolates of F mon...
Collatos C, Barton MH, Moore JN.Plasma fibrinolytic activity was evaluated over 5 consecutive days in 59 horses admitted to the Large Animal Teaching Hospital with acute gastrointestinal diseases. Only horses hospitalized for at least 5 days were included in the study. Tissue plasminogen activator (tPA) and plasminogen activator inhibitor type-1 (PAI-1) were quantitated using standard chromogenic activity assays. Statistical analyses were performed using analysis of variance; differences were considered significant when P < or = .05. Activity of PAI-1, the primary endogenous inhibitor of fibrinolysis, was significantly incre...
Bracher V, Steiger R, Huser S.In the present study the breath hydrogen (H2) excretion test was combined with the xylose absorption test in 4 normal horses and 9 clinical patients with chronic diarrhea (n = 3) or chronic weight loss without diarrhea (n = 6). All horses underwent a thorough clinical examination. Laboratory evaluations consisted of haematology and serum biochemistry as well as bacteriological and parasitological examination of feces. In addition, serum electrophoresis and abdominocentesis was performed in all the clinical patients. Gastroscopy was carried out in 6 patients and rectal biopsies were obtained fr...
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...
Murray MJ.Ulceration of the gastric squamous epithelial mucosa was induced in 10 horses using a feeding protocol previously shown to expose the gastric mucosa to repeated periods of high acidity. The feeding protocol consisted of alternating feed deprivation with free access to hay. Over a period of seven days, each horse was provided hay for 84 hr and deprived of hay for 84 hr. Hay was never withheld for longer than 24 hr at a time. Gastroscopy was performed on each horse at the beginning of the protocol after 12 hr of feed deprivation, and after a total of 36 hr, 60 hr, and 84 hr of feed deprivation. ...
Collatos C, Barton MH, Schleef R, Prasse KW, Moore JN.Much of the pathophysiology associated with equine gastrointestinal diseases is attributed to the effects of endotoxin on haemostasis. Because little is known about the responses of the equine fibrinolytic system to endotoxin, regulation of the system was investigated. Tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) were identified as the primary plasminogen activator and plasminogen activator inhibitor, respectively, in equine blood. Under experimental conditions, the equine fibrinolytic system responded to endotoxin in a manner similar to that repo...
Purcell KL, Johnson PJ, Kreeger JM, Wilson DA.An 8-year-old Missouri Fox Trotter mare was examined because of intermittent, low-grade abdominal pain and weight loss for 3 months. Incomplete jejunal obstruction, caused by a granulomatous mass in the wall of the jejunum, was identified during exploratory celiotomy. Pythium insidiosum was identified as the cause of the granuloma. This case suggests that enteric pythiosis may develop in horses that are geographically distant from the Gulf Coast.
Gillis JP, Taylor TS, Puckett MJ.A 5-year-old Arabian stallion was treated medically 6 days for proximal enteritis. On the sixth day, exploratory celiotomy verified the diagnosis and ruled out other intraluminal and extraluminal gastrointestinal tract obstructions. A gastrojejunostomy was performed. The horse had trouble maintaining and gaining weight in the first year after surgery, but 8 years after surgery, the owner reported that the horse was doing well.
de Freitas MG, Dos Santos GH, Silva DLZ, Costa TD, Borges DGL, Reckziegel GH, Cleveland H, do Nascimento Ramos CA, Pereira FB, de Almeida Borges F.The strategic control of equine gastrointestinal nematodes is based on epidemiology. The aim is the reduction of the population of parasites as a whole in the hosts and environment while seeking the number of treatments that achieves the balance between not risking animal health and not exerting selection pressure for resistant parasites. This is the first study in a tropical region to assess a strategic control protocol for equines. The study was conducted in the municipality of Anastácio in the state of Mata Gross do Sul, Brazil, over a two-year period from April 2021 to March 2023, involvi...
Kelly RF, Galbraith E, Zahid O, Chaundhry U, Sargison N.Grazing animal species kept in zoological collections can be at risk of significant gastrointestinal nematode (GIN) infections. Little work has been undertaken to understand GIN species dynamics within co-grazed hosts. This study aimed to describe the species diversity of GINs found in faeces of grazing animals in a Scottish zoological collection. Methods: At a single time-point, freshly voided faecal samples were collected randomly from horses, sheep, goats, alpacas and deer. Faecal worm egg counts (FWECs) were conducted using a saturated saline centrifugal flotation cuvette technique. The ne...
Attia MM, Omar HM.This study aimed to collect data on the most common parasites of the family equidae which is spp. During this study we focused on the prevalence rate in the world; the distribution of the six known species: life cycle and the pathogenesis of the larvae inside the hosts were investigated around the world. Molecular as well as serological diagnoses were analyzed. Possible treatment strategies which were fully studied; are also, included. () and larvae are the main present larvae in equine; other species, such as , , and may be present. Although the female flies' egg-laying behavior can annoy...
Wernery U, Nothelfer HB, Böhnel H, Collins WR.An acute outbreak of a C. perfringens Type C enterotoxemia in a polo club killed 8 polo ponies in less than 24 hours. Hay with a massive fungal contamination (Aspergillus and Fusarium sp.) is suspected to have triggered the enterotoxemia. Our cases show numerous similarities with the previously reported cases of EIC. However, acute toxic tubulonephrosis in the necropsied horses and longstanding elevation of AST and gamma GT-levels in survivors is unique in our cases.
Averay K, Ward M, Verwilghen D.To compare perforation rates between tri-layer nitrile-latex and natural rubber latex surgical gloves after single-layer end-to-end jejunojejunal anastomoses in equine cadavers. Methods: Prospective randomized ex-vivo study. Methods: Pairs of surgical gloves (n = 46) worn during jejunojejunal anastomoses. Methods: Tri-layer nitrile-latex and rubber latex pairs of gloves were equally but randomly allocated to a right-handed surgeon performing 46 single-layer end-to-end jejunojejunal anastomoses on cadaveric material. Number and location of perforations were determined with the water leak test...
Salcedo R, Gomez DE, Krueger E, Koenig J.Small intestinal incarceration in a rent within the ileocecal fold is an uncommon finding in horses. This report describes the history, clinical signs, and surgical findings in a horse with small intestinal strangulation due to a rent at the ileocecal fold. . L’incarcération du petit intestin dans une déchirure du pli iléo-caecal est une constatation rare chez les chevaux. Ce rapport décrit l’anamnèse, les signes cliniques et les constatations chirurgicales d’un cheval atteint d’une strangulation du petit intestin en raison d’une déchirure dans le pli iléo-caecal.(Traduit par ...
Stas E, Kranenburg L, Witt P, de Grauw J, van den Brand J, Ensink J, Brommer H.Meckel's diverticula are a rare cause of small intestinal strangulation, diagnosed at laparotomy or necropsy. This congenital anomaly of the gastrointestinal tract originates from a remnant of the vitelline duct. In reported equine cases, they present as a full-thickness diverticulum on the antimesenteric border of the distal jejunum or proximal ileum. Methods: On laparotomy a Meckel's diverticulum positioned at the mesenteric side was found to be the cause of small intestinal strangulation. This position is very uncommon and to the best knowledge of the authors there is no unambiguous descrip...