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.
Nadeau JA, Andrews FM, Mathew AG, Argenzio RA, Blackford JT, Sohtell M, Saxton AM.To measure pH, volatile fatty acid (VFA) concentrations, and lactate concentrations in stomach contents and determine number and severity of gastric lesions in horses fed bromegrass hay and alfalfa hay-grain diets. Methods: Six 7-year-old horses. Methods: A gastric cannula was inserted in each horse. Horses were fed each diet, using a randomized crossover design. Stomach contents were collected immediately after feeding and 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after feeding on day 14. The pH and VFA and lactate concentrations were measured in gastric juice Number and severity of gastri...
Cohen ND, Vontur CA, Rakestraw PC.To identify risk factors for enterolithiasis in horses. Methods: Matched case-control study. Methods: 26 horses with enteroliths, 104 horses with other causes of colic that underwent surgery (52 horses, surgical control group) or were treated medically (52 horses, nonsurgical control group). Methods: Medical records were reviewed for horses with enteroliths and control horses. Information collected included signalment, anamnesis, and findings on physical examination and clinicopathologic testing at admission. Horses with enteroliths and control horses were compared by means of conditional logi...
Schumacher J, Edwards JF, Cohen ND.A review of reported cases of inflammatory bowel diseases (IBDs) of horses for which no etiology was identified included cases of granulomatous enteritis (GE), multisystemic eosinophilic epitheliotropic disease (MEED), lymphocytic-plasmacytic enterocolitis (LPE), and idiopathic eosinophilic enterocolitis (EC). The terms EC and MEED were both used to describe a disease in horses characterized by infiltration of intestine and extraintestinal tissues with eosinophils. We use EC to describe IBD characterized by only intestinal infiltration by eosinophils. Horses with GE, MEED, or LPE are usually e...
Rakestraw PC, Snyder JR, Sanders KM, Shuttleworth WC.To evaluate electrical activity of jejunal circular muscle in horses and characterize electrical responses to stimulation by intrinsic inhibitory neurons. Methods: Portions of jejunum obtained from horses euthanatized for reasons other than gastrointestinal tract disease. Methods: Isolated circular muscle preparations were perfused with oxygenated modified Krebs solution. Glass microelectrodes were used for intracellular recording of membrane potentials from single smooth muscle cells. Electrical activity and responses to electrical field stimulation (EFS) of intrinsic neurons in the presence ...
Roussel AJ, Hooper RN, Cohen ND, Bye AD, Hicks RJ, Bohl TW.To evaluate the effect of erythromycin on motility of the ileum, cecum, and pelvic flexure of horses during the postoperative and post-recovery periods. Methods: 8 healthy adult horses. Methods: Horses were anesthetized and bipolar electrodes were implanted in smooth muscle of the ileum, cecum, and pelvic flexure. Approximately 4, 16, and 24 hours (postoperative recording sessions) and at least 8 days (post-recovery recording session) after surgery, myoelectric activity was recorded before and after administration of erythromycin (0.5 mg/kg). Results: Following erythromycin administration, myo...
Nieto JE, Rakestraw PC, Snyder JR, Vatistas NJ.To evaluate effects of erythromycin, lidocaine, and metoclopramide on smooth muscle of the pyloric antrum (PA), proximal portion of the duodenum (PD), and middle portion of the jejunum (MJ) of horses. Sample Population-Strips of smooth muscle from 7 horses. Methods: Isolated muscle strips were suspended in a bath and attached to isometric force transducers. Once stable spontaneous contractions were observed, agents were added. Isometric stress responses were compared with the amplitude of spontaneous contractions. Results: A single dose of erythromycin to the PA increased contractile amplitude...
McKenzie DM, Diffay BC.Cryptosporidial oocyst shedding was detected in a 2.5-year-old Quarterhorse stallion with diarrhoea. Based on the detection of cryptosporidial oocysts, and the absence of other aetiological agents or enteropathogens, cryptosporidiosis was presumptively diagnosed. This case was unusual because cryptosporidial oocyst shedding is primarily found in some immunocompromised or immature horses, and has not been reported in healthy mature horses.
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.
Lohmann KL, Roussel AJ, Cohen ND, Boothe DM, Rakestraw PC, Walker MA.To evaluate the correlation between halftime of liquid-phase gastric emptying (T50), determined with nuclear scintigraphy using technetium Tc 99m pentetate, and absorption variables of orally administered acetaminophen. Methods: 6 mature horses. Methods: Technetium Tc 99m pentetate (10 mCi) and acetaminophen (20 mg/kg of body weight) were administered simultaneously in 200 ml of water. Serial left and right lateral images of the stomach region were obtained with a gamma camera, and T50 determined separately for counts obtained from the left side, the right side and the geometric mean. Power ex...
Sandin A, Andrews FM, Nadeau JA, Nilsson G.Nervous excitation was induced by various means in horses provided with a gastric cannula. Insulin hypoglycaemia profoundly inhibited the basal acid output and volume secreted from the stomach. No clear effect on acid secretion was noted after administration of bethanechol, as the acid output was covered by the copious secretion of saliva. Atropine almost abolished the basal acid output. Sensoric stimulation by teasing caused a slight but not significant increase in the total acid output. These data suggest that cholinergic excitation might play a role in the stimulation of both volume and aci...
Argenzio RA.Ulceration of the nonglandular, stratified squamous mucosa of the equine and porcine stomach is a common event in both species, although in pigs the fatality rate is significant and it is an economically important disease. Because the barrier function of this mucosa in horses and pigs appears similar, it is probable that similar pathophysiological mechanisms may be responsible for the initiating lesions and reparative events. Recent studies of ulcer pathogenesis in the pig have shown that feed preparation or prolonged fasting can result in disruption of the normal stratification of gastric con...
Andrews FM, Sifferman RL, Bernard W, Hughes FE, Holste JE, Daurio CP, Alva R, Cox JL.Equine gastric ulcer syndrome (EGUS) is very common among performance horses, with a reported prevalence of approximately 90% in racehorses, and also > 50% in foals. Omeprazole, an acid pump inhibitor 5 times more potent than ranitidine, has been used with great success to treat EGUS. This multicentre study of Thoroughbred racehorses with endoscopically verified gastric ulcers was designed to demonstrate the efficacy of an equine oral paste formulation of omeprazole in the treatment and prevention of recurrence of EGUS. Of the 100 horses entered into the study, 25 were sham-dosed for the full ...
Berschneider HM, Blikslager AT, Roberts MC.Gastric contents were sampled in horses via nasogastric tube to determine changes in pH and bile salt concentrations during feeding and fasting periods. The horses were rotated through 4 feeding protocols. (1) hay; (2) hay with twice daily grain meals; (3) and (4) fasting preceded by either hay only or hay and grain. Sequential, hourly samples were collected from 3 horses prepared with gastric cannulas. Horses were fed hay twice daily and grain mix either twice daily or in small aliquots dispensed every 90 min. The horses were sampled during normal feeding or after 14 h of feed deprivation. Ga...
Murray MJ, Eichorn ES, Holste JE, Cox JL, Stanier WB, Cooper WL, Cooper VA.A paste formulation of the H+,K(+)-ATPase inhibitor omeprazole was evaluated in Thoroughbred foals and yearlings for its safety and acceptability. Twenty foals age 11-16 weeks and 20 yearling horses age 15-17 months were included and gastroscopic examinations performed 1-3 days before and at the end of each trial. Lesions were scored on a scale of 0 to 3 and animals allocated based on endoscopic lesion score and sex, with 4 animals in each of 5 replicates. Dosages of 4 mg omeprazole/kg bwt or sham treatment were administered once daily for 28 days, from a syringe graduated in 50 lb (22.68 kg) ...
Vatistas NJ, Snyder JR, Nieto J, Thompson D, Pollmeier M, Holste J.Gastric ulceration has been found to occur in 80-90% of Thoroughbreds in active race training. Previously, variable success has been reported using mucosal surface protectants and H2 receptor antagonist. Omeprazole, a substituted benzimidazole, has been shown to inhibit gastric acid secretion in both man and animals. Fourteen horses, in active race training and with endoscopic evidence of moderated to severe gastric ulceration were divided into 2 groups: Group 1 (7 horses) were given placebo paste orally once daily for 28 days; Group 2 (7 horses) received 1.54 g active omeprazole in the placeb...
Vatistas NJ, Sifferman RL, Holste J, Cox JL, Pinalto G, Schultz KT.Gastric ulceration is a prevalent condition of racehorses. A number of models of gastric ulceration have been described, but none mimic the conditions of a horse in training. The objectives of this study were to determine whether gastric ulcers could be induced and maintained in a group of horses in simulated race training. In addition, serum cortisol was measured on a weekly basis to investigate the possibility that stress may be important in the pathogenesis of gastric ulceration. Thirty horses used in the trial were fed Bermuda grass hay and 6 kg of a concentrate diet, and exercised 6 days/...
MacAllister CG, Sifferman RL, McClure SR, White GW, Vatistas NJ, Holste JE, Ericcson GF, Cox JL.A multicentre, blinded, randomised complete-block, field trial was conducted with 140 horses and foals age 4 weeks-28 years to determine if omeprazole paste is effective and safe in promoting healing of spontaneous gastric ulcers under a variety of field conditions and in different breeds and ages of horses. Horses in the study had gastric ulceration as determined by gastroscopy and were divided into replicates of 4 or 5 animals. One horse in each replicate was assigned randomly to receive an empty omeprazole syringe (sham-dosed control) and the remaining horses received omeprazole paste once ...
Daurio CP, Holste JE, Andrews FM, Merritt AM, Blackford JT, Dolz F, Thompson DR.In a multicentre trial, 13 cannulated horses were treated orally once daily with a paste that delivered omeprazole at a dose of 4 and 5 mg/kg bwt in a 2-period crossover design to evaluate steady state gastric acid suppression. In each period, basal (unstimulated) and pentagastrin-stimulated gastric output were evaluated at 5-8 h after 5 doses, at 13-16 h after 10 doses, and at 21-24 h after 15 doses. Baseline data for gastric acid secretion were collected once for each horse in the month prior to initiation of omeprazole treatment. The inhibition of gastric acid secretion relative to baseline...
Merritt AM.This article represents an attempt to provide an overview of the current knowledge of equine gastroduodenal secretory and motor activity, with respect to how these functions are controlled and interact. First, the equine gastric mucosal anatomy is discussed in comparison with other monogastric species, with some attention directed at the large nonglandular portion in relation to its function, or lack thereof. Next, control of gastric acid secretion, as assessed by the collection of gastric contents from a cannula or continuous measurement of their changes in pH, is reviewed, pointing out that ...
Haven ML, Dave K, Burrow JA, Merritt AM, Harris D, Zhang D, Hickey GJ.The antisecretory activity of omeprazole on gastric acid when administered i.v., intragastrically or per os, was evaluated in 2 female and 3 castrated male horses. Each horse had been prepared with a chronic indwelling gastric cannula. A single i.v. administration of omeprazole (1.5 mg/kg bwt) was effective in abolishing basal and pentagastrin (PG)-stimulated acid secretion. Once daily, nasogastric administration of omeprazole in acid-stable granules for 5 days inhibited acid secretion in a dose-dependent manner: 57% (1.5 mg/kg bwt) and 98% (5.0 mg/kg bwt) reduction of PG-stimulated acid secre...
Venner M, Lauffs S, Deegen E.This study compared the study of a pectin-lecithin complex (Pronutrin) on gastric ulcer healing during an 11 day period in 2 groups of 12 horses each. Twenty-four horses suffering from gastric lesions of differing severity were selected from a larger group of clinical cases on the basis of gastroscopic examination. Both gastric mucosal erosions as well as gastric ulcers were found in the 2 mucosal regions (pars nonglandularis and pars glandularis). The gastric mucosal lesions occurred predominantly in the pars nonglandularis in the vicinity of the margo plicatus. The 24 horses were divided equ...
Sandin A, Andrews FM, Nadeau JA, Doherty TJ, Nilsson G.The effect of intramuscular (i.m.) omeprazole (0.25 or 1.0 mg/kg bwt; LD and HD), respectively, on volume, total acid output (TAO) and pH of the gastric juice was studied during 24 h in 5 horses with a chronically implanted gastric cannula. Whether secretion in controls was basal or stimulated with pentagastrin (8 micrograms/kg bwt/h), volume (NS) and TAO (P < 0.01, NS) gradually decreased and pH increased (P < 0.05, NS). Omeprazole significantly reduced the average basal TAO by 49 +/- 6% (LD) and 88 +/- 3% (HD) and the stimulated TAO by 64 +/- 2% and 97 +/- 1%. Basal pH in controls was 2.1-4....
Vatistas NJ, Snyder JR, Carlson G, Johnson B, Arthur RM, Thurmond M, Zhou H, Lloyd KL.Although gastric ulcers have been identified relatively frequently in racing Thoroughbreds, there have been no large scale studies to determine their effect on health and performance. Two hundred and two Thoroughbred horses in active race training were selected by the attending veterinarians for gastro-endoscopic examination. Images of the stomach mucosa were stored in a digitised format for subsequent evaluation. The number of ulcers and a score of severity were determined. Gastric ulceration of the squamous mucosa was identified in 82% of horses. Seventy-three (39%) horses displayed clinical...
Hough ME, Steel CM, Bolton JR, Yovich JV.Four cases of ulceration and stricture of the right dorsal colon were encountered. Ulceration of the right dorsal colon is generally associated with nonsteroidal anti-inflammatory drug (NSAID) toxicosis but there are few reports of stricture following ulceration. All four horses had recent phenylbutazone use: three had been given doses well in excess of the recommended dose and in one the dose was marginally above those recommended but was combined with administration of other NSAIDs. All four horses presented with intermittent low-grade colic, weight loss and ventral oedema. Diarrhoea was als...
Conner AL, Davis AJ, Porr CA.This study evaluated the effect of a dietary supplement on the treatment of equine gastric ulcer syndrome (EGUS). Gastroscopy was performed on university riding horses of mixed breeds at two locations and only horses exhibiting gastric ulcers were selected to participate in this study (location A, n = 13; location B, n = 15). Gastric ulcer severity was assessed using two different methods depending on location before treatment (Pre). After gastroscopy, horses were fed the supplement in addition to their regular diet for 44 d (14-d adaptation period followed by 30-d feeding period). All horses ...
Roussel AJ, Hooper RN, Cohen ND, Bye AD, Hicks RJ, Bohl TW.To evaluate the effect of erythromycin on motility of the ileum, cecum, and pelvic flexure of horses during the postoperative and post-recovery periods. Methods: 8 healthy adult horses. Methods: Horses were anesthetized and bipolar electrodes were implanted in smooth muscle of the ileum, cecum, and pelvic flexure. Approximately 4, 16, and 24 hours (postoperative recording sessions) and at least 8 days (post-recovery recording session) after surgery, myoelectric activity was recorded before and after administration of erythromycin (0.5 mg/kg). Results: Following erythromycin administration, myo...
Schoster A, Altermatt N, Torgerson PR, Bischofberger AS.To describe outcome and complications after large intestinal trocarization in equids with colic and identify factors associated with nonsurvival and clinically relevant peritonitis (CRP). Methods: 228 (198 horses, 24 ponies, and 6 donkeys and mules) equids with colic that underwent large intestinal trocarization. Methods: Medical records from 2004 through 2015 were reviewed for equids with colic that underwent large intestinal trocarization. Factors associated with nonsurvival in all (ie, surgically and medically treated) equids and with CRP in medically only treated equids were identified. Me...
Delesalle C, van Acker N, Claes P, Deprez P, de Smet I, Dewulf J, Lefebvre RA.Prokinetic drugs used to treat gastrointestinal ileus in man have equivocal results in horses. In man, prokinetic drugs have 5-hydroxytryptamine4(5-HT4) receptors as their target, but little is known about the 5-HT-receptor subtypes in the equine small intestine. Objective: Functional and immunohistochemical identification of the serotonin receptor subtype(s) responsible for the 5-HT induced contractile response in the equine circular jejunum. Methods: Isometric organ-bath recordings were carried out to assess spontaneous and drug-evoked contractile activity of equine circular jejunum. Histolo...
MacNicol JL, Renwick S, Ganobis CM, Allen-Vercoe E, Weese JS, Pearson W.The equine gastrointestinal (GI) microbiota is intimately related to the horse. The objective of the current study was to evaluate the microbiome and metabolome of cecal inoculum maintained in an anaerobic chamber or chemostat batch fermenter, as well as the fecal slurry maintained in an anaerobic chamber over 48 h. Cecal and fecal content were collected from healthy adult horses immediately upon death. Cecal fluid was used to inoculate chemostat vessels (chemostat cecal, = 11) and vessels containing cecal fluid (anaerobic cecal, = 15) or 5% fecal slurry (anaerobic fecal, = 6) were maintain...
Roger T, Bardon T, Ruckebusch Y.The electrical and mechanical activity of the large intestine and its response to administration of opiate mu and kappa agonists were assessed from electrodes and inductograph coils chronically implanted on the cecocolic segment in six ponies given a diet of hay and concentrates. Before the drugs were given, migrating complexes propagating from the cecum into the colon occurred at the rate of 1.5 to 16/hour. During this propulsive activity, the cecocolic sphincter opened and closed allowing the outflow of cecal contents and preventing the backflow of colic contents. Each pony was used as its o...
Bullimore SR, Corfield AP, Hicks SJ, Goodall C, Carrington SD.In horses, ulceration of the non-glandular region of the stomach is common and has been attributed to the lack of a protective mucus covering. This study aimed to determine whether the non-glandular region is covered by a mucus layer. A mixture of antibodies raised against human gastric mucin (MUC 5 AC) showed a tissue distribution in the glandular region of the equine stomach similar to that seen in humans. Dot blots of mucus from the glandular and non-glandular regions showed cross-reactivity with these antibodies. Various histological fixation and processing techniques were compared for the...
Ford TS, Freeman DE, Ross MW, Richardson DW, Martin BB, Madison JB.The case records of 26 horses with ileocecal intussusception over a 7-year period were reviewed to determine clinical features of the disease and response to treatment. The median age of horses with ileocecal intussusception was 1 year and ranged from 2 weeks to 19 years. There was no apparent gender or breed predisposition to this disease. An acute form of ileocecal intussusception was diagnosed in 19 horses with signs of moderate to severe abdominal pain of less than or equal to 24 hours' duration, and a chronic form was diagnosed in 7 horses with signs of intermittent, mild to moderate abdo...
Ousey JC, Prandi S, Zimmer J, Holdstock N, Rossdale PD.To determine the effect of diet on energy intake, loss, and metabolism in foals 2 to 7 days old. Methods: 14 pony foals. Methods: Group-A foals suckled their dams, group-B foals were fed milk replacer, and group-C foals were fed by total parenteral nutrition (TPN). Energy balance studies were performed over 8-hour periods on postpartum days 2, 4, and 7. Results: Mean gross energy (GE) intake of group-A foals increased between days 2 and 7. Approximately 3% of GE was excreted in urine and feces, and energy expenditure remained constant. These foals were in positive energy balance, and mean body...
St-Pierre B, de la Fuente G, O'Neill S, Wright AD, Al Jassim R.We investigated the community structure of bacteria that populate the stomach of the Brumby, a breed of feral horses from the Australian outback. Using a 16S rRNA gene clone library, we identified 155 clones that were assigned to 26 OTUs based on a 99.0 % sequence identity cutoff. Two OTUs represented 73.5 % of clones, while 18 OTUs were each assigned only a single clone. Four major bacterial types were identified in the Brumby stomach: Lactobacillaceae, Streptococcaceae, Veillonellaceae and Pasteurellaceae. The first three groups, which represented 98.1 % of the Brumby stomach library clones,...
Jansson A, Harris P, Davey SL, Luthersson N, Ragnarsson S, Ringmark S.Straw's low energy content means it is a roughage option for horses with low energy requirements. Previously, in a field study, straw was associated with an increased risk for gastric ulcers. This study evaluated the effect on gastric ulcers, metabolic profile and behaviour of replacing, in a forage-only ration, 50% of the daily allowance with wheat straw. Six equines were studied in a 2 × 21-day cross-over design. The control diet (CON: 100% grass forage) and the straw diet (S: 50% grass forage and 50% straw [DM basis]) were iso-energetic. Gastroscopy was performed prior to the study and on ...
Patton ME, Andrews FM, Bogers SH, Wong D, McKenzie HC, Werre SR, Byron CR.Ileus is a common life-threatening problem in horses, and currently available treatments may be ineffective. The purpose of this study was to determine whether bit chewing, a form of sham feeding, decreases the gastric emptying time (GET), small intestinal transit time (SITT), and total orocecal transit time (OCTT) in clinically normal horses in a prospective crossover study. Nine healthy horses were acclimated and fed a standardized diet. Following 24 h of fasting, self-contained video endoscopy capsules and acetaminophen were administered into the stomach via a nasogastric tube. Each horse u...
Bergstrom TC, Sakai RR, Nieto JE.A mare was euthanized because of gastric rupture secondary to complete duodenal obstruction by 2 bezoars located in the pylorus and proximal duodenum. Infrared spectroscopy showed that the bezoars were composed of psyllium. The mare had been receiving treatment with a pelleted psyllium product at 4 times the recommended dosage. Veterinarians should be aware that treatment of colic in horses with pelleted psyllium products could be associated with gastric impaction. Rupture gastrique catastrophique secondaire à des pharmacobézoards de psyllium en boulettes chez un cheval. Une jument a été e...
Jacobson CC, Sertich PL, Mc Donnell SM.To investigate effects of a 5-day oral misoprostol regimen recommended for use in horses as a gastrointestinal mucosal cytoprotectant during colic on mid-gestation pregnancies. Objective: To monitor cervical tone, ultrasonographic characteristics of the uterus, cervix and conceptus, as well as serum progesterone and oestrone sulphate concentrations, and observations of general health, behaviour and comfort of mid-gestation mares given a 5-day course of misoprostol or control treatment. Methods: Eleven light horse and pony mares with known breeding dates were administered 5 µg/kg bwt misoprost...
Murray A, Cottrell DF, Woodman MP.Equine grass sickness (EGS) is a pan-dysautonomia of horses that involves central and peripheral neuronal degeneration and ultimately depletion. This is the first reported functional study on the motility of equine intestine taken immediately post mortem from horses with EGS. Strips of smooth muscle from the small intestine of healthy and EGS-affected horses were suspended in an organ bath and their motility was measured isometrically. The activity of the cholinergic system was studied. Physostigmine enhanced the motility of all muscle strips. Tissues taken from horses suffering from acute gra...
Koenig JB, Rodriguez A, Colquhoun JK, Stämpfli H.During exploratory laparotomy of a foal with colic, a congenital abnormally developed large colon was identified incidentally. Long-term follow-up showed that the colt was more prone to gas-colic with diet and exercise changes than were other horses, due possibly to the short colon. Malformation congénitale du côlon (côlon court) chez un poulain Standardbred âgé de 4 mois. Au cours d’une laparotomie exploratrice chez un poulain atteint de colique, une malformation congénitale du gros côlon a été identifiée de façon fortuite. Un suivi à long terme a montré que le poulain était d...
Stick JA, Chou CC, Derksen FJ, Arden WA.Isolated jejunal segments were perfused at a constant blood flow rate to determine simultaneously the effects of xylazine on intestinal vascular resistance, motility, compliance, and oxygen consumption in 12 anesthetized ponies. Xylazine was infused into the artery perfusing the intestinal segment (group 1), or into the jugular vein as a single IV bolus (group 2), or 3 times as IV boluses repeated at 10-minute intervals (group 3). Dose-response curves in group 1 indicated a biphasic response to the drug with vasoconstriction, increased motility, and increased oxygen consumption at lower doses ...
Crowhurst RC, Simpson DJ, McEnery RJ, Greenwood RE.Intestinal surgery in the foal is seldom necessary but some conditions in which it is essential are well recognized. The foal is a good surgical subject but success depends mainly on operating promptly before irreversible degenerative changes take place. Exploratory laparatomy is recommended whenever mechanical obstruction is suspected. Indications fall broadly into two main categories: 1. Cases arising from congenital defects. These form a miscellaneous group and present considerable difficulties in diagnosis and effective treatment. 2. Cases related to acute onset of obstruction, mainly due ...
Pietra M, Morini M, Perfetti G, Spadari A, Vigo P, Peli A.In recent years, gastric ulceration has been recognized as a common, possibly performance-limiting disease, of adult horses. The aim of this study was to compare endoscopic features, histological diagnosis, and mRNA levels of various cytokines (TNF-alpha, IL-1beta, and IL-13) from horse gastric biopsies. Eleven horses suffering from equine gastric ulcer syndrome and seven horses with normal histological gastric features were assessed. No correlation between endoscopic features and histology (i.e., the gold standard) was observed. Based on histological diagnosis, a significant (p < 0.05) increa...
Rosenfeld I, Austbø D, Volden H.Fecal samples were collected to evaluate mathematical models to describe the kinetics of digesta passage in the segments of the equine gastrointestinal tract and to compare the passage kinetics of hay and oats. Four Norwegian Cold-blooded trotters (cecally cannulated, approximately 500 kg of BW) were fed Cr-mordanted hay and Yb-marked oats with their morning meal. The meal consisted of 2 kg of hay and 1 kg of oats processed as ground, pelleted, extruded, or micronized. Each horse was fed each type of oats on different days of collection, after a 5-d adaptation period, in a 4 x 4 Latin square d...
Morrison PK, Newbold CJ, Jones E, Worgan HJ, Grove-White DH, Dugdale AH, Barfoot C, Harris PA, Argo CM.Bacteria residing in the gastrointestinal tract of mammals are crucial for the digestion of dietary nutrients. Bacterial community composition is modified by age and diet in other species. Although horses are adapted to consuming fibre-based diets, high-energy, often high-starch containing feeds are increasingly used. The current study assessed the impact of age on the faecal bacteriome of ponies transitioning from a hay-based diet to a high-starch diet. Over two years, 23 Welsh Section A pony mares were evaluated (Controls, 5-15 years, n = 6/year, 12 in total; Aged, ≥19 years, n = 6 Year 1;...
McConnico RS, Argenzio RA, Roberts MC.The objective of this project was to determine early tissue biochemical events associated with increased colonic secretion during the acute stage of castor-oil-induced colitis by measuring cecal mucosal and submucosal malondialdehyde (MDA) and prostaglandin E2 (PGE2), levels in ponies. Intestinal tissue (inflamed or healthy) samples were obtained from 4 age- and sex-matched Shetland ponies. Biochemical methods were used to determine MDA and PGE2 levels in intestinal tissue samples from inflamed and healthy equine intestine. Inflamed tissue MDA and PGE2 levels increased with time after castor o...
Morton AJ, Grosche A, Matyjaszek SA, Polyak MM, Freeman DE.The effects of prostaglandins and nonsteroidal anti-inflammatory drugs (NSAIDs) on repair of equine intestinal mucosa are important since most horses with gastrointestinal diseases are routinely treated with NSAIDs, such as flunixin meglumine (FM), and these drugs can be toxic to equine gastrointestinal mucosa. Objective: Flunixin meglumine would not affect recovery of equine colonic mucosa in vitro, 18 h after a reversible ischaemic injury. Methods: In 14 anaesthetised horses, a segment of pelvic flexure was subjected to 2 h of ischaemia and the horses were allowed to recover for 18 h. Seven ...
Li Z, Luo Z, Hu D.Diarrhea serves as a vital health indicator for assessing wildlife populations post-reintroduction. Upon release into the wild, wild animals undergo adaptation to diverse habitats and dietary patterns. While such changes prompt adaptive responses in the fecal microbiota, they also render these animals susceptible to gastrointestinal diseases, particularly diarrhea. This study investigates variations in fecal microorganisms and hormone levels between diarrhea-afflicted and healthy Przewalski's horses. The results demonstrate a significant reduction in the alpha diversity of the fecal bacterial ...
Torcivia C, McDonnell SM.Gastric ulcer disease and other potentially painful gastric conditions are among the most common afflictions adversely affecting the welfare of domestic equids. A large percentage of affected animals may not display the classic signs of gastric disease, such as unexplained weight loss, poor hair coat, and inappetence until the disease becomes severe. As a clinical service within our equine referral hospital, we routinely evaluate 24-h video recorded samples of horses to assist clinicians in identifying subtle discomfort and potential sources or to scan for infrequent neurologic or cardiac-rela...
François AC, Cesarini C, Taminiau B, Renaud B, Kruse CJ, Boemer F, van Loon G, Palmers K, Daube G, Wouters CP, Lecoq L, Gustin P, Votion DM.Hypoglycin A and methylenecyclopropylglycine are protoxins responsible for atypical myopathy in equids. These protoxins are converted into toxins that inhibit fatty acid β-oxidation, leading to blood accumulation of acylcarnitines and toxin conjugates, such as methylenecyclopropylacetyl-carnitine. The enzymes involved in this activation are also present in some prokaryotic cells, raising questions about the potential role of intestinal microbiota in the development of intoxication. Differences have been noted between the faecal microbiota of cograzers and atypical myopathy-affected horses. Ho...
Lu Y, Ru P, Qin S, Zhang Y, Fu E, Cai M, Tuohuti N, Wu H, Zhang Y, Zhang Y.Gastrointestinal parasitic diseases pose significant health risks to equine populations. This study investigated the epidemiological patterns of equine gastrointestinal parasites in Xinjiang by analyzing 83 fecal samples collected from Ili ( = 62) and Urumqi ( = 21) between August and November 2024. The modified McMaster technique was employed to quantify fecal egg counts (EPG) and was complemented by morphological identification to assess infection dynamics related to geography, breed specificity, and management practices. The results demonstrated an overall infection prevalence of 66.3% (55/...
