Intestinal pathology in horses encompasses a range of disorders affecting the structure and function of the equine gastrointestinal tract. These conditions can include inflammatory, infectious, obstructive, and degenerative diseases that impact the intestines. Common intestinal pathologies in horses include colitis, enteritis, and intestinal torsion, each with distinct histopathological features and clinical presentations. Diagnostic approaches often involve clinical examination, imaging techniques, and histological analysis to identify the underlying pathology. This page aggregates peer-reviewed research studies and scholarly articles that explore the etiology, diagnosis, and management of intestinal pathologies in equine medicine.
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...
Barclay WP, McCracken RJ, Phillips TN, Foerner JJ.Chronic nongranulomatous intestinal inflammation was found during laparotomy in 7 horses. The clinical signs consisted of recurrent abdominal pain in all horses. Anti-inflammatory agents (corticosteroidal and nonsteroidal agents) appeared to be effective for controlling the signs. Surgical removal of the involved intestine also was effective. Nonocclusive or temporary mesenteric ischemia was proposed as a cause of the intestinal lesions.
Schumacher J, Hanrahan L.An excessively long ileal stump, the result of a previous jejunocecostomy, had intussuscepted into the cecum and subsequently obstructed the cecocolic orifice of a 12-year-old Quarter Horse mare. Clinical signs were dehydration, ileus, and endotoxemia. The diagnosis was made at necropsy.
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...
Gossett KA, Cleghorn B, Adams R, Church GE, McCoy DJ, Carakostas MC, Flory W.Increased anion gap (AG) was due, in part, to L-lactic acidosis in 14 of 14 horses with intestinal disorders. In a few horses, increased whole blood concentrations of D-lactate made a minor contribution to the AG. However, the increase in AG was often greater than the sum of the increases in these 2 acid anions. This unexplained increase was not a result of increases in whole blood pyruvate, 3-hydroxybutyrate, or acetoacetate concentrations or serum albumin or phosphate concentrations. Identification of other anions causing increased AG could lead to better understanding, diagnosis, and treatm...
Wawrzeńska M.In this paper, the effect of ascorbic acid on motoric activity of the intestines of rabbits, pigs, cows, sheep and horses has been determined, and a possible participation of the adrenogenic system in this mechanism has been shown. In experiments in vitro the motility of the duodeum, jejunum, caecum and colon in the animals mentioned abowe was recorded by the method of Magnus after administration of ascorbic acid. Diastolic reactions were observed in all animals, which were much greater in small intestines than in large ones. To elucidate the diastolic mechanism under the influence of ascorbic...
Snyder JR, Pascoe JR, Holland M, Kurpershoek CJ.Measurements of jejunal, ileal, and large colon (pelvic flexure) surface O2 tension (PSO2) were made in halothane-anesthetized horses with a nonheated miniature oxygen polarographic electrode. Assisted ventilation with 100% O2 was used to maintain PaCO2 tension at 50 +/- 8 mm of Hg while mean arterial blood pressure was maintained greater than or equal to 70 mm of Hg. Mean +/- SD PSO2 for the intestinal segments were: jejunum (horses 1 to 4), 71 +/- 20 mm of Hg; ileum (horses 1 to 4), 61 +/- 8 mm of Hg; and pelvic flexure of the large colon (horses 1 to 10), 55 +/- 13 mm of Hg. The response of...
Platt H.A retrospective study was made of 20 horses with severe and extensive chronic disease of the small intestine. Many of the animals had clinical evidence of malabsorption, with progressive loss of weight, hypoalbuminaemia and sometimes anaemia. All but two of the horses were Thoroughbreds. The pathology was diverse. Nine of the cases were alimentary lymphomas (Platt, 1986) and five had lymphocytic and eosinophilic infiltrations in the bowel wall which were considered to be probable reactions to parasitic invasion. One had acute thrombosis associated with partial occlusion of the anterior mesente...
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 […]
Edwards GB.Intraoperative techniques for assessing the viability of ischaemic bowel are discussed. Intravenous administration of sodium fluorescein appears useful but further investigation of the method is required. Methods of resection and anastomosis of small intestine are described and illustrated, including the use of automatic stapling instruments.
Johnson R.A review of the literature on intestinal atresia of domestic animal species and humans was done. The 5 types of intestinal occlusions described in human infants are atresia type 1, atresia type 2, atresia type 3, stenosis, and the "apple peel" or "Christmas tree" deformity. The intestinal defects described in domestic animal species such as the bovine, equine and porcine are similar to those of human infants. The "T-formation", an intestinal defect of the bovine resembling atresia type 3, and rectal stricture, an acquired intestinal defect of the porcine resembling stenosis, were described rec...
Eysker M, Mirck MH.The distribution of inhibited early third stage Cyathostominae larvae in different parts of the large intestine of the horse was studied in 20 Shetland ponies necropsied in autumn 1982, 1983 and 1984. The location of the larvae in the large intestinal wall was studied by histological examination of the intestines of the eight ponies from 1984. Inhibited larvae were located predominantly and more or less equally in the caecum and the ventral colon. Generally fewer early L3 were in the dorsal colon. In 1984 a considerable proportion (mean 17%, range 9.7-36.9%) of the inhibited larvae was found i...
Dean PW, Robertson JT.Seven horses were used to compare the Gambee, the crushing, and a 2-layer inverting suture pattern composed of a simple continuous layer in the mucosa oversewn with a continuous Lembert pattern in the seromuscular layer. Horses were evaluated at 30 days for adhesion formation, lumen diameter, and quality of healing at the anastomotic sites. One horse was euthanatized 9 days after surgery after 24 hours of ileus and colic; necropsy revealed septic peritonitis and widespread adhesions. One horse had no adhesions. The remaining horses had adhesions associated with 50% of the Gambee and 50% of the...
Sullins KE, Stashak TS, Mero KN.Arteriovenous (ischemic strangulation obstruction, ISO) or venous (hemorrhagic strangulation obstruction, HSO) occlusions were created in the jejunum of 5 anesthetized horses and were left in situ for 1-, 2-, or 3-hour intervals. Segments were evaluated grossly for color, thickness, and motility. The horses were euthanatized, and the degree of mucosal slough, edema, congestion, and hemorrhage was determined histologically. Segments subjected to ISO became dark, but did not contain edema or hemorrhage. Segments subjected to HSO were characterized by progressive congestion, edema, and hemorrhage...
Scott EA, Todhunter R.In 2 cases of chronic intestinal intussusception in horses, one involved jejunum and the other, ileum. The only clinical signs observed were intermittent colic. Surgery was performed on both horses, with successful outcomes.
Widders PR, Stokes CR, David JS, Bourne FJ.IgG, IgA, IgM and albumin concentrations were measured in serum, follicular fluid and oviductal, uterine and intestinal secretions of the horse. Follicular protein concentrations were found to be dependent on serum concentration and molecular size. Of the immunoglobulins only IgG was detectable in oviductal secretions, but IgG:albumin ratios did not differ significantly from those in serum. IgG, IgA and IgM were measured in uterine secretions, with IgG predominant. Serum transudation into uterine secretions was minimal. In intestinal secretions, IgA levels were slightly higher than IgG, with a...
Pablo LS, Purohit RC, Teer PA, Newton JC, Hammond LS.Total strangulation obstruction of the caudal part of the jejunum was induced in 3 groups (each of 3 ponies) for 2, 4, and 6 hours. Coagulation tests which included blood platelet counts, prothrombin time, activated partial thromboplastin time, activated coagulation time, plasma fibrinogen level, and fibrin/fibrinogen degradation products assay were performed at specified time intervals for 1 week or until death of the experimental ponies. Another 3 ponies (sham-operated) were similarly treated, except that intestinal strangulation obstruction (ISO) was not induced. Necropsy was done on ponies...
Bailey JV, Fretz PB.Two incidents of penetrating wounds into the abdominal cavity of horses are presented. In both events these had resulted in penetraton of the intestinal tract. Both animals had received only minimal veterinary attention in the acute stage and had survived with the formation of intestinal fistulae.Attempts at surgical repair resulted in failure in one animal and in closure of the fistula in the second with some subsequent cosmetic defect.
Vonderfecht SL, Bowling AT, Cohen M.A congenital and probably hereditary neurological defect has been identified in the intestinal tract of six foals produced from the breeding of overo (a type of spotting pattern) horses. The foals had white hair and pink skin with the exception of occasional pigmented foci about the muzzle, ventral abdomen, and hindquarters. The foals appeared normal at birth, but within a few hours developed symptoms of colic. At necropsy, the only significant finding was a narrow, pale segment of large intestine. This abnormality either was confined to the small colon and rectum or involved the entire colon ...
Barclay WP, Phillips TN, Foerner JJ.Intussusception associated with Anoplocephala perfoliata infection was found in 5 horses. The unusual types of intussusception and the presence of tapeworms at the leading edge of the intussuscipiens suggested tapeworms as the cause of the problem. Lesions attributable to tapeworm attachment on the mucosa were found to fit a mechanical model of intussusception. Treatment of two of the horses and some of their pasturemates with pyrantel pamoate caused elimination of intact tapeworms.
Oikawa M, Kaneko M, Yoshikawa T.To elucidate the pathomorphogenesis of extremely shortened small-intestinal villi, occurring spontaneously in neonatal foals, the morphology of the small intestine with stunted villi was studied in eight cases. All intestinal wall elements and the villi were poorly developed. Most villi were found to be extremely short throughout the entire length of the small intestine. The villous core consisted of undifferentiated, fibroblast-like cells held loosely together by ground substance which was rich in glycosaminoglycan. Development of the villous lamina propria was poor with respect to capillarie...
Schumacher J, Hanrahan L.An excessively long ileal stump, the result of a previous jejunocecostomy, had intussuscepted into the cecum and subsequently obstructed the cecocolic orifice of a 12-year-old Quarter Horse mare. Clinical signs were dehydration, ileus, and endotoxemia. The diagnosis was made at necropsy.
Rhoads WS, Parks AH.A 10-year-old castrated male pony was examined for intermittent signs of abdominal pain of 3 days' duration. An incarceration of the small colon through a rent in the gastrosplenic ligament was found. Resection and end-to-end anastomosis were performed on the affected portion of the small colon. The pony recovered and returned to its previous degree of activity. Incarceration of the small intestine and large colon through rents in the gastrosplenic ligament are documented, although involvement of the small intestine is more common. To the best of our knowledge, incarceration of the small colon...
Bailey JV, Fretz PB.Two incidents of penetrating wounds into the abdominal cavity of horses are presented. In both events these had resulted in penetraton of the intestinal tract. Both animals had received only minimal veterinary attention in the acute stage and had survived with the formation of intestinal fistulae.Attempts at surgical repair resulted in failure in one animal and in closure of the fistula in the second with some subsequent cosmetic defect.
Lotstra RJ, van den Broek J, Power T, Marr CM, Wijnberg ID.Atrial fibrillation is a common equine arrhythmia. Quinidine alone, or with digoxin are common treatments. Studies on outcome in Warmblood populations in which duration of the AF is often unknown are limited. Objective: To identify the factors that are associated with the success of full treatment cardioversion with oral medication, and establish whether there are differences in these factors between institutions. Methods: Retrospective case series using patient records of Equine University Clinic of Utrecht University and Rossdales Equine Hospital, Newmarket. Methods: Forty-nine horses treate...
Sasaki N, Yoshihara T.Seven Thoroughbred horses were laparotomized and Force Transducers were fixed on the proximal jejunal and cecal serosa. After observation of the digestive tract motility in consciousness, cisapride (0, 0.5, 0.75 or 1 mg/kg) was orally administered. In horses treated with 0.75 mg/kg or 1.0 mg/kg cisapride, the migrating contraction (MC) of the jejunum was significantly increased in frequency.
Maire U, Genton M, Vitte-Rossignol A.A 16-year-old, French saddlebred horse was referred for examination because of colic signs, diagnosed with incarceration of the jejunum in a mesoduodenic rent, and subsequently treated surgically (with an end-to-end anastomosis of the jejunum and an enterotomy of the pelvic flexure). The horse initially recovered without complications; however, on the following day, it exhibited moderate signs of endotoxemia and severe serosanguineous discharge from the abdominal wound. Abdominal ultrasonography revealed substantial peritoneal effusion, necessitating the placement of an abdominal drain. The bl...
Freeman DE, Kilgallon EG.To determine if venous strangulation obstruction (VSO) of the distal half of the equine small intestine would increase length of that segment. Methods: Halothane-anesthetized horses were assigned randomly to 3 groups of 5 horses: Group 1 (controls)--the entire small intestine was measured and rubber-shod clamps were applied to mark each end of the most distal 50% of the small intestine; Group 2--same procedure, except that VSO was induced in the distal 50% of the small intestine for 180 minutes; and Group 3--same initial procedure, except that VSO was induced for 90 minutes and followed by rep...
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...
Hélie P, Ammann VJ, Kervern I.A 6-year-old, standardbred mare was presented for colic of 12 h duration. Transrectal palpation revealed intestinal distension of unknown cause. The mare was euthanized. At necropsy, segmental jejunoileal incarceration and strangulation through an opening in the spleen was observed. This opening was considered to be a congenital defect.
MacHarg MA, Foerner JJ, Phillips TN, Barclay WP.The medical management of three horses with simple and strangulating small intestinal obstructions was unsuccessful and was therefore supported by surgical bypasses. Jejunocecostomies were used to treat horses with postoperative paralytic ileus that was unresponsive to medical management. These horses had abdominal pain, gastric distention, heart rate elevations greater than 60/minute, and small intestinal distention on rectal palpation. Two horses experienced weight loss which responded to bypass removal. The bypass effectively decreased the need for intravenous fluid administration and repea...
Barclay WP, McCracken RJ, Phillips TN, Foerner JJ.Chronic nongranulomatous intestinal inflammation was found during laparotomy in 7 horses. The clinical signs consisted of recurrent abdominal pain in all horses. Anti-inflammatory agents (corticosteroidal and nonsteroidal agents) appeared to be effective for controlling the signs. Surgical removal of the involved intestine also was effective. Nonocclusive or temporary mesenteric ischemia was proposed as a cause of the intestinal lesions.
Sloet van Oldruitenborgh-Oosterbaan MM, van der Velden MA.A review of displacements and surgery of the large colon is given on the basis of two cases. A four-year-old Dutch Warmblood mare was referred, one week before foaling, for colic of twelve hours duration. At rectal palpation a large uterus was found, but no cause for the colic. Laparotomy revealed a colonic volvulus and resection of about 75% of the large colon was necessary. A dead foal was born five days postoperatively, but the mare recovered well. A nine year-old Dutch Warmblood stallion with a history of frequent colic had been treated for nephrosplenic entrapment three times. Resection o...