Gastrointestinal health in horses encompasses the study of the structure, function, and disorders of the equine digestive system. The equine gastrointestinal tract is complex, consisting of the stomach, small intestine, cecum, and large intestine, each playing a specific role in digestion and nutrient absorption. Research in this area often focuses on common disorders such as colic, gastric ulcers, and parasitic infections, which can impact a horse's overall health and performance. Investigations examine factors affecting gastrointestinal health, including diet, management practices, and the microbiome. This page compiles peer-reviewed research studies and scholarly articles that explore the physiology, pathology, and management of gastrointestinal health in horses.
Mair TS, Hillyer MH, Taylor FG, Pearson GR.Specificity of the oral glucose tolerance test (OGTT) for the diagnosis of small intestinal malabsorption in the horse was assessed by comparing the results of OGTT with the results of a histopathological examination of the small intestine in 42 adult horses affected by chronic weight loss. The horses were assigned to three groups on the basis of the results of the test. Five horses were considered to have a normal OGTT absorption result (Group 1); all the horses had a histologically normal small intestine. Twenty-five horses had a partial malabsorption result (Group 2) seven of which had norm...
Pearson RA, Merritt JB.Four donkeys and four ponies maintained in climate rooms, were provided with meadow hay or barley straw supplemented with minerals and vitamins ad libitum. Both diets were given to all animals for periods of 21 days. Measurements were made during the last seven days following single doses of two non-absorbable markers (Cr-fibre and Co-EDTA). After six weeks the donkeys repeated the trial, walking 14 km and ascending 260 m five days per week. At rest ponies ate more than donkeys, however the donkeys showed a higher digestibility of dry matter (DM), organic matter (OM) and acid detergent fibre (...
Dieckmann M, Deegen E.Twelve horses with clinical symptoms of a gastric disorder were studied by gastroscopy. Symptoms of gastric disorders were periprandial colic, bruxism, ructus and reflux. Preliminary to gastroscopy the horses were fasted for 24 h. Access to water was not restricted. The gastroscopy could be conducted easily using a fiberscope 2.5 m in length and 11 mm in outer diameter. While ulcers were present in the squamous fundus of all horses only one horse showed ulceration of the glandular fundus. Solitary ulcers near the margo plicatus were found in horses with mild clinical symptoms. In contrast, dif...
Rose PL, Schumacher J, Taylor TS.An extensive stricture of the left dorsal colon in a Thoroughbred colt was resected and the colon was anastomosed. In two horses, circumferential strictures at the pelvic flexure 2.5 to 3 cm long were corrected with a modified Heineke-Mikulicz pyloroplasty technique. The horses were reported to be doing well at 6, 8, and 45 months, respectively.
Burns GA, Cummings JF.Sellers et al. (1979, Am. J. Phys., 237: E457-E464) proposed a pelvic flexure pacemaker mechanism to account for the bidirectional contraction waves needed to both retain ingesta within the right ventral colon for cellulose digestion and terminal fermentation and to transport the digesta distad once the process has been completed. To corroborate the presence of a pelvic flexure pacemaker, we prepared whole mount samples of the tunica muscularis from 23 horses at ten sites along the large colon, cecum and jejunum. Following smooth muscle enzymatic digestion, somata of the myenteric plexus were ...
Roger T, Cabanie P.The histologic study on six horses of the ileo-caecal and caeco-colic junctions confirms their sphincteral structure. It appears that the activity of the muscular fibres, identified in the ileo-caecal and caeco-colic plica, modulates the curvature of the junctions and thus, blocks, as sphincters, the reflux of contents from the caecum into the ileum and from the colon into the caecum. But on the other hand, the pelvic flexure does not possess any microscopic organization to stop the reflux of contents from the dorsal colon into the ventral colon.
Morris DD.Endotoxemia remains the leading cause of death in horses, being intimately involved in the pathogenesis of gastrointestinal disorders that cause colic and neonatal foal septicemia. Endotoxins, normally present within the bowel, gain access to the blood across damaged intestinal mucosa, or endotoxemia occurs when gram negative organisms proliferate in tissues. Endotoxins are removed from the circulation by the mononuclear phagocyte system, and the response of mononuclear phagocytes to these lipopolysaccharides (LPS) play an important role in determining the severity of clinical disease. Macroph...
Khittoo G, Vermette L, Nappert G, Lariviere N.In mammalian species studied previously, pepsinogen consisted of biochemically different groups of isozymogens. By use of gel filtration chromatography and electrophoresis, we isolated a predominant pepsinogen from the gastric mucosa of a horse. Peptide mapping with V8 protease revealed differences with its porcine homologue. However, porcine and equine pepsinogens, when activated to pepsin, had a similar pattern of activity when hemoglobin was used as substrate. Those results suggest that differences must exist in the primary structure of the pepsinogens of the 2 species.
Edwards JF, Ruoff WW.Cecal rupture has been reported as a complication of tape-worm infestation or parturition in horses. Often it occurs with no apparent predisposing factors. Spontaneous rupture on the medial surface of the cecum occurred in 2 of 19 foals, 12 to 24 hours after gastric endoscopy. The sites of rupture were identical in both foals. Rupture occurred despite prior deworming, withholding of food and water before anesthesia, and care in induction of anesthesia and recovery. Surgeons should be aware of the potential of cecal rupture in horses anesthetized for elective surgery.
Bello TR.A controlled test was done in 30 naturally infected ponies to evaluate the antiparasitic activity of the dienbendazole analog VET 220-S given alone or with trichlorfon (TCF) by nasogastric intubation. Six ponies were nontreated; 6 were given VET 220-S (5.0 mg/kg); 6 were given TCF (40 mg/kg); 6 were given VET 220-S (2.5 mg/kg) and TCF (40 mg/kg); and 6 were given VET 220-S (5.0 mg/kg) and TCF (40 mg/kg). All ponies were euthanatized and necropsied 7 or 8 days after treatment. Draschia megastoma, Oxyuris equi, Strongylus vulgaris, S edentatus, and small strongyles were removed efficaciously by ...
Takehana K, Masty J, Abe M, Yamaguchi M.The ultrastructure and histochemistry of the duodenal glands of the pony (Equus caballus) was examined in four horses. Unlike that of most species except for the rabbit, the submucous glands of the horse contain two distinct cell types, serous and mucous. These cells are described.
Madison JB, Dreyfuss DJ, Charlton C.A 4-year-old Thoroughbred gelding with a history of chronic colic was referred for evaluation of signs of abdominal pain. Exploratory laparotomy revealed a diverticulum of the distal portion of the ileum located between the layers of the mesentery. The diverticulum was similar in location and appearance to acquired ileal diverticula described in human beings. Complete bypass of the diverticulum by ileocecostomy resulted in apparent resolution of the chronic colic in this horse.
King JN, Gerring EL.Post operative ileus (POI) is a common and serious complication of colic surgery in the horse. There is a high correlation between the incidence of POI and the presence of ischaemic bowel, suggesting a role for endotoxin. 0.1 micrograms/kg endotoxin was administered intravenously to six ponies with chronically implanted gastrointestinal electromechanical recording devices. It produced profound disruption of normal fasting bowel motility patterns, with an inhibition of gastric contraction amplitude and rate, left dorsal colon contraction product and small colon spike rate. In the small intestin...
Weldon AD, Rowland PH, Rebhun WC.A 12-year-old Morgan gelding was examined for colic of 3 days duration. Signs of depression, colic, diarrhea, and endotoxemia persisted despite aggressive medical therapy and surgical exploration. Culture results from gastric fluid and feces yielded many colonies of Clostridium perfringens. This organism also was recovered from peritoneal fluid 10 days after admission; consequently, the horse was euthanized. At necropsy, a localized gas-filled, necrotic stomach wall was found; many mucosal and submucosal gas blebs were visible. Culture of this tissue yielded Clostridium perfringens. Emphysemat...
Orsini JA, Dreyfuss DJ, Vecchione J, Spencer PA, Uhlman R.The effects of a potent new histamine-2 (H2) receptor antagonist, BMY-25368, were studied on gastric acid secretion in 5 foals from which food was withheld. Doses of 0.02, 0.11, 0.22, and 1.10 mg/kg of body weight were administered IM in a randomly assigned treatment sequence. Following BMY-25368 administration, hydrogen ion concentration was decreased and mean pH was higher than baseline values in a dose-response pattern. At the 0.22 and 1.10 mg/kg doses, the high pH was sustained for greater than 4 hours. The BMY-25368 thus may be useful for treating gastric ulcer disease in horses.
Masty J, Stradley RP.The equine Paneth cell response to a shift in the microbial balance of the intestinal tract was studied by inducing an acute episode of alimentary laminitis in 6 mature ponies. The normal bacterial population of the gut was modified by administration of a carbohydrate-rich ration. During acute laminitis a dramatic degranulation of the Paneth cells occurred in the intestinal glands throughout the duodenum, jejunum, and ileum. Bacteriocidal lysozyme, which was immunohistochemically identified as a component of the Paneth cell secretory granule, was evident in the glandular lumina and in degranul...
Campbell-Thompson ML, Merritt AM.Equine gastric secretion was studied using a gastric cannula model after fasting (basal) and pentagastrin infusion. Gastric secretory rate, pH, osmolality, and electrolyte concentrations and outputs were determined over a 5-h period. Dose-response tests estimated that the maximally effective intravenous dose of pentagastrin was between 3 and 6 micrograms.kg-1.h-1. Basal secretory rate was 278 +/- 29 (SE) ml/15 min, and the pH was 2.00 +/- 0.31. Pentagastrin infusion at 6 micrograms.kg-1.h-1 increased secretory rate to 533 +/- 60 ml/15 min and decreased pH to 1.41 +/- 0.11. Basal gastric acid c...
King JN, Gerring EL.The effect of pre-treatment with a selective platelet-activating factor (PAF) antagonist, WEB 2086, on the actions of low-dose endotoxin was evaluated in ponies prepared with gastrointestinal strain gauges. Endotoxin (0.1 microgram/kg i.v.) produced a marked reduction in gastric contraction amplitude and rate, and an increased frequency and reduced duration of jejunal phase III activity fronts (AFs). WEB 2086 (6.6 mg/kg) administered i.v. 10 min before the endotoxin, produced significant antagonism (P less than 0.001) of the effect of endotoxin on gastric contraction amplitude and rate. The co...
Sivula NJ, Trent AM, Kobluk CN.Nonsurgical correction of a renosplenic entrapment of the large colon was attempted in a mare, using a rolling technique. After correction, the mare had initial improvement in clinical signs, but later developed signs of abdominal discomfort. A ventral midline celiotomy was performed, and a pelvic flexure impaction and large intestinal volvulus were found and corrected.
Bertone AL, Cockerell GL, Lee RE, Stashak TS.Light microscopy, morphometry, and scanning electron microscopy were used to examine the mucosal morphologic features of 7 intestinal specimens (3 from the small intestine; 4 from the large intestine) from each of 8 horses 1 year after sham operation (group 1; n = 3) or extensive large-colon resection (group 2; n = 5). Qualitative light microscopic examination did not reveal differences between groups, but morphometry revealed significantly (P less than 0.05) greater intercrypt area and distance in horses with colon resection and this was most pronounced in the cecum and remaining right ventra...
Bertone AL, Toofanian F, Stashak TS.Lactase, maltase, sucrase, and alkaline phosphatase activities were determined in the intestinal mucosa from 3 locations in the small intestine and 4 locations in the large intestine 1 year after extensive large-colon resection (group 1; n = 5) and 1 year after sham operation (group 2; n = 3) in horses. Lactase, maltase, and sucrase activities were similar (P greater than 0.05) between group-1 and group-2 horses in all locations measured in the intestinal tract. Alkaline phosphatase activity in the remaining large colon of group-1 horses was significantly (P less than 0.05) greater than the ac...
Clarke LL, Roberts MC, Argenzio RA.The association of feeding practices with the development of digestive disorders in horses has long been recognized, although the underlying mechanisms had been barely considered. The physiologic consequences of meal frequency may help to explain the relationship and prove to be of major significance in the induction of many conditions. Many Equidae kept for performance and leisure activities are fed high-energy, low-forage rations twice daily, with limited access to hay or grazing. Rapid ingestion of such meals stimulates a copious outpouring of upper alimentary secretions and results in tran...
Gerhards H, Klein HJ, Offeney F.A diagnostic approach based on clinical and radiographic examinations for evaluation of young foals and small ponies with acute abdominal discomfort is presented. Standing right to left lateral abdominal radiographs were taken of 54 foals and 6 ponies using a previously described technique. Interpretation of the radiographs was in conjunction with all clinical and laboratory findings and patient management. Using this approach, the site and cause of acute abdominal discomfort could be diagnosed accurately in 55 of 60 (91%) patients as confirmed by clinical, surgical or necropsy findings. Typic...
Meschter CL, Gilbert M, Krook L, Maylin G, Corradino R.Phenylbutazone, a non-steroidal anti-inflammatory drug known to produce intestinal erosions, was administered intravenously (13.46 mg/kg bodyweight) to 12 horses which were killed after 24, 48, 72 and 96 h. Eight untreated horses served as controls. Annular erosions in the duodenum and mucosal necrosis in the colon were seen after 48 h which progressed in severity. The erosions were characterised by sloughing of the surface epithelium, subepithelial cleft and bleb formation, necrosis of the lamina propria, degeneration of the walls of subsurface capillaries and microthrombosis. Large numbers o...
Kamerling SG, Hamra JG, Bagwell CA.Endogenous opioid peptides have been implicated in the regulation of pain perception, behaviour, gastrointestinal activity and other physiological responses. However, the functional role of these peptides in the horse has yet to be elucidated. The opioid antagonist, naloxone, is often administered to infer endogenous opioid effects. In the present study, naloxone (0.75 mg/kg bodyweight) was administered to eight Thoroughbred racehorses and a number of behavioural and autonomic responses were measured. Naloxone produced rapid onset diarrhoea, restlessness, abdominal checking, tachycardia, tachy...
Clarke LL, Argenzio RA.In contrast to in vivo findings, the equine proximal colon fails to demonstrate significant net absorption of Na+ and Cl- under in vitro conditions. The present study was undertaken to determine if endogenous prostanoids are responsible for this apparent lack of ion transport. Proximal colonic tissues from ponies were preincubated in either normal Ringer solution or in Ringer containing 1 microM indomethacin and studied in Ussing chambers containing these solutions. Untreated colonic mucosa demonstrated negligible Na(+)-Cl- absorption in the basal state. In contrast, indomethacin-treated colon...
Baker SJ, Gerring EL, Fox MT.Gastric pH varied widely among eight fasted ponies, of which seven exhibited discrete episodes of spontaneous alkalinisation (SA). SA occurred at all times of the study and no significant variation in the summary variables of pH (median pH, mean pH and percentage of readings exceeding pH 4.0) was noted among the periods 0 to eight, eight to 16 and 16 to 24 hours. The occurrence of SA has significant implications for the performance of acid secretory studies in the fasted pony. There was, however, no significant correlation between pH and plasma gastrin concentration measured using a commercial...
Bevevino KE, Edwards JF, Cohen ND, de Solis CN.Ultrasonography is increasingly being used as a clinical and research method for evaluating the gastrointestinal tract in horses, however published studies comparing ultrasonographic and histologic characteristics of equine intestinal wall layers are currently lacking. Objectives of this prospective, observational, methods comparison, case series study were to compare the layering pattern and thickness of the intestinal wall layers determined using ex vivo and in vivo ultrasonography with those determined using histology. For the ex vivo study, twelve horses were euthanized for reasons unrelat...
Mellor DJ.Physiological challenges facing the perinatal individual are huge. This is partly because of the marked and abrupt change from the intrauterine to the extrauterine environment, but also because the physiological responses to that change depend upon systems whose maturation is affected markedly by birth. Perinatal maturation appears, therefore, both to precede and accompany the physiological adaptations required for neonatal survival. This review does not provide a comprehensive coverage of perinatal physiology but directs attention towards evaluating constraints on foetal and neonatal thermoge...
Taguchi T, Morales Yniguez FJ, Takawira C, Andrews FM, Lopez MJ.Osteoarthritis (OA) accounts for up to 60% of equine lameness. Agmatine, a decarboxylated arginine, may be a viable option for OA management, based on reports of its analgesic properties. Six adult thoroughbred horses, with lameness attributable to thoracic limb OA, received either daily oral phenylbutazone (6.6 mg/kg), agmatine sulfate (25 mg/kg) or a control for 30 days, with 21-day washout periods between treatments. Subjective lameness, thoracic limb ground reaction forces (GRF), plasma agmatine and agmatine metabolite levels were evaluated using an established rubric, a force platform, an...
Morrissey NK, Bellenger CR, Ryan MT, Baird AW.To measure the expression of cyclooxygenase-2 (COX-2) mRNA in gastric biopsy specimens serially obtained from horses before, during, and after an 8-day intermittent feed-deprivation trial and to investigate the mucosal location of COX-2. Methods: 9 mixed-breed horses for retrieval of gastric biopsy specimens and 16 additional horses for immunohistochemical analysis. Methods: Gastric biopsy specimens were obtained from 6 horses; 3 of these horses and 3 more participated in an intermittent feed-deprivation trial 9 weeks later. A quantitative PCR assay was used to determine the amount of COX-2 mR...
Eysker M, Jansen J, Wemmenhove R, Mirck MH.Gastro-intestinal helminth infections of a group of three yearling mare Shetland ponies, which were set-stocked on a small pasture from February until September, were compared with those of a similar group of ponies, which grazed a similar pasture from February to July and subsequently was removed to a pasture which had been grazed by sheep from April to July. In addition both groups were treated with cambendazole when the latter group was removed to the sheep pasture. Pasture larval counts and worm counts demonstrated that the group grazed after the sheep acquired considerably smaller burdens...
Bertone AL, Cockerell GL, Lee RE, Stashak TS.Light microscopy, morphometry and scanning electron microscopy (SEM) were used to examine the mucosal morphology of seven intestinal specimens (three from the small intestine and four from the large intestine) from two horses not subjected to surgery and three horses one year after sham-operation for colon resection. Qualitative and quantitative evaluation revealed similar morphology for all horses except that the unoperated horses had significantly (P < 0.05) fewer goblet cells in the crypts of the large intestine. In the small intestine, SEM demonstrated that villus shape varied and range...
Shmalberg J, Xie H.Acupuncture exerts diffuse analgesic effects through the release of endogenous opioids and other locally and centrally acting mediators. Successful therapeutic interventions for various musculoskeletal conditions in horses are well documented, and acupuncture may significantly enhance performance. The use of acupuncture is specifically supported in treating nonsurgical gastrointestinal disorders, in which specific techniques can alter motility and contribute to visceral analgesia. This article describes the use of acupuncture and Chinese herbal medicine for equine reproductive management and f...
Badino P, Odore R, Re G.Adrenergic receptors (ARs) are the cellular membrane binding sites through which natural catecholamines and sympathomimetic drugs exert their physiological and pharmacological effects. In recent decades, studies to clarify the distribution and function of ARs have been performed mostly on cultured cells, laboratory animals and human target tissues, but little is known about these aspects in domestic animals. This review focuses on AR structure, classification and signalling pathways and on AR subtype distribution in target tissues of some domestic animals, namely dogs, horses and bovines. In t...
Pavone S, Gialletti R, Pepe M, Onofri A, Mandara MT.In this study we investigated the histological changes of the myenteric plexuses and interstitial cells of Cajal (ICC) in gut samples from horses with colic to try to find results useful in the prognostic evaluation of enteric lesions. A morphologic and quantitative study of myenteric ganglia, ganglion cells and neuronal chromatolytic and necrotic changes of 24 horses with colic was performed. For ganglion cells, enteroglial cells and ICC immunolabeling was also performed to identify cell functional disorders. A significant increase of neuronal chromatolysis and necrosis occurred in horses suf...
Lambertini C, Zannoni A, Romagnoli N, Bombardi C, Morini M, Dondi F, Bernardini C, Forni M, Rinnovati R, Spadari A.Large colon volvulus in horses is associated with a poor prognosis, especially when ischemic-reperfusion injury of the affected intestinal tract develops. Proteinase-activated receptor 2 (PAR2) plays an important role in the pathogenesis of inflammation in the gastrointestinal tract. The aim of this study was to evaluate the distribution and expression of PAR2 in colonic pelvic flexure of horses spontaneously affected by large colon volvulus (CVH group). Eight horses admitted for severe abdominal colon volvolus and which underwent surgery were included. Colon samples were collected after enter...
Sasaki N, Nishi Y, Fujiwara Y, Takeyama T, Kumagai H, Senarathna S, Ushiya S, Tokuyama T, Tokuyama T, Tokuyama T, Mii T, Ayaki S, Matsuno K....Gastric ulcers cause appetite loss, poor body condition, and colic in horses. This study investigated the protective effect of a rice fermented extract on the gastric mucosa in 17 healthy Thoroughbreds. For one month, horses in the rice fermented extract (nine horses) and control (eight horses) groups were orally administered a rice fermented extract (100%; 0.2 ml/kg, SID) and tap water (0.2 ml/kg), respectively. Gastric endoscopic images were obtained before and one month after rice fermented extract administration. The gastric ulcer score was lower after administration (median, 1; maximum, 2...
Bookbinder L, Schott HC.To describe refeeding syndrome in an equid without a history of recognized risk factors. Methods: Refeeding syndrome with marked hypophosphatemia developed in an aged miniature donkey gelding during treatment of suspected enterocolitis. Hypophosphatemia (manifested clinically as ileus and neuromuscular weakness) developed despite a short (3 day) history of hyporexia, increased body condition (7/9), and adherence to nutritional recommendations for critically ill equids. Nutritional support included nasogastric enteral feeding with a commercial equine nutrition product claiming to provide 100% o...
Norman T, Chaffin K, Schmitz D.The equine small intestine is challenging to evaluate ultrasonographically. In humans, hydrosonography has been used to improve ultrasonographic images of the small intestine. We hypothesized that fasting horses for 24 h would enhance the ability to image the small intestine transabdominally by separating intestinal loops and reducing intraluminal gas, and that the administration of intragastric contrast agent would further improve that ability. Ten healthy horses were examined ultrasonographically under three treatment conditions: (a) regular diet, (b) after a 24-h fast, and (c) fasted plus i...
Murray A, Pearson GT, Cottrell DF.Small intestine was taken from the caudal flexure of the duodenum and the terminal ileum proximal to the ileocaecal fold of 25 horses, 9 with acute grass sickness (AGS), 12 with subacute grass sickness (SAGS) and 12 with chronic grass sickness (CGS). The motility in the samples was measured isometrically either within 1 h of death or after storage for 24 h at 4 degree C. In control tissue, noradrenaline produced contractions of muscle strips which did not involve a muscarinic cholinergic mechanism and which were unaffected by the alpha 1 antagonist prazosin but were blocked by the alpha 2 anta...
Verhaar N, Hoppe S, Grages AM, Hansen K, Neudeck S, Kästner S, Mazzuoli-Weber G.α2 agonists are frequently used in horses with colic, even though they have been shown to inhibit gastrointestinal motility. The aim of this study was to determine the effect of dexmedetomidine on small intestinal in vitro contractility during different phases of ischaemia. Experimental segmental jejunal ischaemia was induced in 12 horses under general anaesthesia, and intestinal samples were taken pre-ischaemia and following ischaemia and reperfusion. Spontaneous and electrically evoked contractile activity of the circular and longitudinal smooth muscles were determined in each sample with a...
Mueller PO, Allen D.Recent advances in abdominal surgical techniques in the horse have resulted in improved survival rates and reduced postoperative morbidity. The development of abdominal surgical procedures in horses has paralleled the development of safe anesthetic protocols and innovative technological advancements in humans. Irrespective of the species, the application of sound surgical principles is still the foundation of surgical intervention. This article describes recent advances in equine gastrointestinal surgical techniques. The availability and application of innovative intestinal surgical devices an...
Peretich AL, Abbott LL, Andrews FM, Dhar MS.To determine whether expression of mRNA for sodium-potassium adenosine-triphosphatase (NAKA) and sodium-hydrogen exchanger (NHE) in samples of the nonglandular portion of the equine gastric mucosa was altered by exposure to volatile fatty acids (VFAs) in an acidic environment. Methods: 10 horses (5 or = 12 years old). Methods: Samples of the nonglandular portion of the gastric mucosa were collected and exposed in Ussing chambers to Ringer's solution (control samples), Ringer's solution containing a mixture of VFAs (pH, 1.5 or 4.0), or Ringer's solution containing acetic acid (pH, 1.5 or 4.0)....
Fintl C, Pearson GT, Mayhew IG, Stewart Lowden C, Hopwood PA, Palgrave CJ, Proudman CJ, Barrie Edwards G, Taylor SE, Hudson NP.Previous immunohistochemical studies targeting the receptor tyrosine kinase (c-Kit) have demonstrated an apparent reduction in the number of gastrointestinal pacemaker cells--the interstitial cells of Cajal (ICC)--in horses with intestinal motility disorders. This study compared the level of transcription of the c-kit gene encoding this receptor in horses with and without such motility disorders. Transcription levels of this gene were also compared to the density of ICC immunohistochemically positive for the c-Kit antigen. Intestinal samples were collected from 18 horses with intestinal diseas...
Ahmadnejad M, Jalilzadeh-Amin G, Sykes BW.Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), like phenylbutazone (PBZ), are prescribed to treat pain and inflammation in the equine. However, experimentally their use has been associated with the development of Equine Glandular Gastric Disease (EGGD). To evaluate the prophylactic effects of Glycyrrhiza glabra root extracts (GGRE) on EGGD induction following oral administration of PBZ, 12 donkeys were used. Animals were divided into three equal groups (A, B and C) in a randomized block design. A: placebo, B: PBZ (4.4 mg/kg PO q 12 h) and C: PBZ plus GGRE (17.6 mg/kg PO q 24h). Gastroscopy an...
Dieckmann M, Deegen E.Twelve horses with clinical symptoms of a gastric disorder were studied by gastroscopy. Symptoms of gastric disorders were periprandial colic, bruxism, ructus and reflux. Preliminary to gastroscopy the horses were fasted for 24 h. Access to water was not restricted. The gastroscopy could be conducted easily using a fiberscope 2.5 m in length and 11 mm in outer diameter. While ulcers were present in the squamous fundus of all horses only one horse showed ulceration of the glandular fundus. Solitary ulcers near the margo plicatus were found in horses with mild clinical symptoms. In contrast, dif...
Escala J, Gatherer ME, Voûte L, Love S.Altered intestinal permeability is implicated in the pathogenesis of diverse equine medical conditions including alimentary laminitis and protein-losing enteropathies associated with parasitic infection. The aims of this study were to assess the feasibility of applying the 51Cr-EDTA absorption test for the assessment of intestinal permeability in the horse, and to apply this test in horses with experimentally induced alterations in gastrointestinal function. Four healthy ponies were administered 36 MBq of 51Cr-EDTA via naso-gastric tube, and urine samples were collected into polythene bags str...
Swain JM, Licka T, Rhind SM, Hudson NP.A seven-year-old standardbred gelding developed marked signs of colic associated with an acute small intestinal obstruction. Surgical exploration revealed three intramural, circumferential constricting lesions in the small intestine, the two most severe of which were in the jejunum and were resected. The horse was euthanased owing to postoperative complications. Histopathological examination confirmed the diagnosis of idiopathic multifocal eosinophilic enteritis.
Mykkänen AK, Niku M, Ilves M, Koho NM.To characterize the expression of monocarboxylate transporters (MCTs) 1 and 4 and the ancillary protein CD147 in the intestinal tract of healthy equids and determine the cellular location of CD147 in the intestinal epithelium. Methods: 12 healthy horses and ponies slaughtered for meat production or euthanized for reasons unrelated to gastrointestinal tract disease. Methods: The entire gastrointestinal tract was removed from each equid within 45 minutes after slaughter or euthanasia. Tissue samples were obtained from the antimesenteric side of the duodenum, jejunum, ileum, middle part of the ce...
Burns GA.At several locations along the equine cecum and colon, the outer longitudinal portion of the tunica muscularis is gathered into discrete bands of smooth muscle and connective tissue called "teniae". In this study, the disposition of the teniae ceci and coli was traced along the equine intestinal tract. It was discovered that, in several instances, arrays of teniae converge toward the valves and sphincters which separate the various intestinal compartments. The teniae may also provide support for and directionality to, peristaltic contraction waves. The tissue proportions of the teniae vary in ...
Bergren AL, Credille BC, Epstein KL, Giguère S.To compare clinical data of horses with entrapment of the small intestine by the gastrosplenic ligament (ESIGL) to clinical data of horses with other strangulating small intestinal lesions. Methods: Retrospective case series. Methods: Medical records (January 2001-December 2011) of horses that had exploratory celiotomy for acute abdominal pain associated with strangulating small intestinal lesions were reviewed. Signalment, physical examination findings, clinicopathologic variables, surgical findings and surgical procedures performed, postoperative data and short-term survival were recorded. R...
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.
MacAllister CG, Sangiah S, Mauromoustakos A.Using video gastroscopy, the efficacy of a Histamine-H2 type receptor antagonist (WY 45, 727) was investigated in young ponies with spontaneous and experimentally induced gastric ulcers. Oral administration of WY 45, 727 at 2 mg/kg and 10 mg/kg of body weight every 12 hours for 14 days resulted in complete healing of spontaneous gastric ulcers in the non-glandular portion of the stomach in 2/5 (40%) and 3/4 (75%) of the ponies, respectively, compared (P < 0.05) to 0/5 (0%) placebo-treated ponies. After intramuscular administration of flunixin meglumine at 1.5 mg/kg body weight every 8 hours fo...
Tetens J, Venugopal CS, Holmes EP, Koch CE, Hosgood G, Moore RM.To evaluate the in vitro effects of adenosine tryphosphate (ATP) on vasomotor tone of equine colonic vasculature. Methods: Arteries and veins from the left ventral colon of 14 mixed-breed horses euthanatized for reasons unrelated to cardiovascular or gastrointestinal tract disease. Methods: Endothelium-intact and -denuded arterial and venous rings were precontracted with 10(-7) and 1.8 x 10(-8) M endothelin-1, respectively. In 1 trial, endothelium-intact rings were also incubated with 10(-4) M N omega-nitro-L-arginine methyl ester (L-NAME) to inhibit nitric oxide (NO) production. Adenosine tri...
Cedrola F, Bordim S, D'Agosto M, Dias RJP.The aims of this study were to identify and quantify the gastrointestinal ciliates from Brazilian domestic horses, to compare the data obtained with previous studies and to review data on ciliate communities associated with horses around the world. We used eight domestic horses, kept under extensive management. Fecal samples were obtained immediately after defecation of animals and fixed in 18.5% formaldehyde. We identify 24 species of endosymbiotic ciliates, distributed in two subclasses, two orders, five families and 13 genera. The ciliate composition was similar among the animals analyzed. ...
