The equine stomach is a complex organ responsible for the initial stages of digestion in horses. It is divided into two main regions: the non-glandular (squamous) region and the glandular region, each with distinct functions and susceptibilities to conditions such as ulcers. The stomach's acidic environment aids in breaking down food particles, while enzymes initiate the digestion of proteins. The equine stomach is adapted for continuous grazing, with relatively small capacity and rapid emptying into the small intestine. This page aggregates peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and common disorders of the horse's stomach, as well as their implications for equine nutrition and health management.
Muñoz-Prieto A, Llamas-Amor E, Contreras-Aguilar MD, Ayala I, Martín Cuervo M, Cerón JJ, Hansen S.Ammonia (NH3) and bicarbonate (HCO3) have been related to gastric ulcers in humans. Ammonia is considered a possible cause of gastric ulcers, whereas bicarbonate has a protective function. The presence of ulcers in the stomach of horses is defined as Equine Gastric Ulcer Syndrome (EGUS), which is a frequent disease in this species, and it has been associated with changes in saliva composition, such as in analytes related to inflammation, immune system and oxidative stress. The objectives of this study were (1) to perform an analytical validation of two automated spectrophotometric assays, one ...
Galinelli NC, Bamford NJ, de Laat MA, Sillence MN, Harris PA, Bailey SR.Insulin dysregulation in horses is characterised by hyperinsulinaemia and/or tissue insulin resistance and is associated with increased risk of laminitis. There is growing evidence in other species that dopamine attenuates insulin release from the pancreas; however, this has yet to be examined in horses. The present study aimed to identify whether there are cells capable of producing or responding to dopamine within the equine gastrointestinal mucosa and pancreas. Tissue samples were collected from the stomach, small and large intestines, and pancreas of six mature horses following euthanasia....
Zhang Y, Zhang K, Wang M, Wu X, Liu J, Chu H, Zhang D, Li K, Huang H.Endangered Przewalski's horses have faced severe infections from (Diptera, Gastrophilidae) in Xinjiang's Kalamaili Nature Reserve (KNR). This study examines 's development and infection patterns in embryonic and larval stages, crucial for understanding horse botfly disease in desert grasslands. For the incubation of fertilized eggs, we established the six distinct temperature gradients: 16 °C, 20 °C, 24 °C, 28 °C, 30 °C, and 32 °C. Using the least squares method, we calculated the correlation between the developmental threshold temperature of the eggs and their cumulative effecti...
Menzies-Gow NJ, Shurlock T.Feedstuffs are often recommended to mitigate potential damage from acid associated with equine squamous gastric disease (ESGD). In acidic conditions, pectin alters its structure to one like mucus and binds the stomach mucosa, whilst alfalfa has a strong intrinsic acid buffering capacity. The study aimed to determine whether feeding a commercial beet pulp/alfalfa/oat fibre mix aids ESGD healing and/or prevention of recurrence. Ten adult horses with naturally occurring ESGD were included. All animals were treated with omeprazole as per the attending veterinarian's recommendation and randomly all...
Haardt H, Romero AE, Boysen SR, Tan JY.Abdominal ultrasonography is valuable in the diagnosis of equine colic. Fast localized abdominal sonography of horses (FLASH) enables practitioners with limited experience to perform ultrasonography in emergency settings. However, many practitioners only possess rectal format linear array transducers (RFLT). The hypotheses are: (a) A low frequency curvilinear transducer (LFCT) and RFLT will detect free abdominal fluid and abnormal small intestinal loops with similar frequency during FLASH, and (b) there will be a difference between the transducers for detection of gastric abnormalities and nep...
López-Martínez MJ, Lamy E, Cerón JJ, Ayala I, Contreras-Aguilar MD, Henriksen IH, Muñoz-Prieto A, Hansen S.Equine gastric ulcer syndrome (EGUS) is currently one of the more frequent diseases in horses. We aimed to identify changes in the salivary proteome in horses with EGUS at diagnosis and after successful treatment by using gel proteomics. Saliva samples were collected from nine horses with EGUS before and after treatment and nine matched healthy controls. SDS-PAGE (1DE) and two-dimensional gel electrophoresis (2DE) were performed, and significantly different protein bands and spots were identified by mass spectrometry. Horses with EGUS had increases in proteins such as adenosine deaminase (ADA)...
Daniel J, Arnold C, Winter K, Scharner D.The aim of the study was to clarify to what extent the sonographic representation of the stomach changes depending on its filling state. Methods: In a prospective controlled study, warmblood horses presented for gastroscopy were assessed sonographically. The examinations took place when the horses were fed normally (measurement 1), after 12 hours of food deprivation (measurement 2), after insufflation of air during gastroscopy (measurement 3) and after removal of air from the stomach at the end of the gastroscopy (measurement 4). The following objective parameters were recorded: Number of inte...
Fitzgerald DM, Cash CM, Dudley KJ, Sibthorpe PEM, Sillence MN, de Laat MA.Active glucagon-like peptide-1 (aGLP-1) has been implicated in the pathogenesis of equine insulin dysregulation (ID), but its role is unclear. Cleavage of proglucagon (coded by the GCG gene) produces aGLP-1 in enteral L cells. Objective: The aim in vivo was to examine the sequence of the exons of GCG in horses with and without ID, where aGLP-1 was higher in the group with ID. The aims in vitro were to identify and quantify the expression of GCG in the equine intestine (as a marker of L cells) and determine intestinal secretion of aGLP-1. Methods: Genomic studies were case-control studies. Expr...
Banse HE, Piero FD, Andrews FM, Garcia-Abarca N, Watanabe TTN.To compare small intestinal inflammation with gastric inflammation in horses with and without equine gastric glandular disease (EGGD), we evaluated endoscopic, macroscopic, and microscopic findings of the glandular stomach and microscopic findings of the small intestine. Methods: 36 horses. Methods: Horses underwent endoscopy and were scored for EGGD. After euthanasia, stomachs were collected and macroscopically evaluated. Normal pyloric mucosa, glandular lesions, and small intestinal (duodenum, mid-jejunum, and ileum) samples were collected and processed for microscopic examination. Cellular ...
Asgari P, Amniattalab A.The equine stomach consists of two separate non-glandular and glandular sections. Despite the incidence of most lesions in the non-glandular region, both stomach parts are prone to lesions. In this study, 41 hybrid-native horses, including 24 stallions and 17 mares, were examined over five years. In total, 27 horses (65.85%) that were sampled had lesions, including erosion, granuloma, or both on the glandular region of the stomach. Occurrence of gastric erosive and granulomatous lesions had no significant relationship with the age and gender of horses or the sampling season (>0.05). Moreove...
Julliand S, Buttet M, Hermange T, Hillon P, Julliand V.Nutritional factors are suggested to influence the incidence and severity of glandular gastric disease (GGD) in horses. Objective: To retrospectively assess whether dietary fermentable carbohydrates increase the severity of GGD and to prospectively evaluate whether the partial substitution of concentrates by dehydrated alfalfa would decrease GGD severity scores. Methods: In total, 82 trotters from 4 training centers exercised ≥5 days/week. Methods: Multicenter retrospective observational study, and prospective 2-arm randomized trial. Glandular mucosae were observed by gastroscopy and score...
Poradowski D, Chrószcz A.The study consisted of the immunohistochemical analysis of fundic and pyloric mucosa in the equine stomach between the 4th and 11th month of gestation. The accessible material was classified into three age groups using the CRL method. The adult reference group was used to define potential differences between foetal and adult populations of gastric APUD cells. The samples were preserved, prepared, and stained according to the standard protocols. The immunohistochemical reaction was assessed using the semi-quantitative IRS method. The results were documented and statistically analysed. The most ...
Epstein KL, Hall MD.Knowledge of the effects of feeding and nasogastric tube placement and manipulation on gastric ultrasound is limited. Given the variability in duration since feeding and the ubiquitous use of nasogastric tubes in horses with colic, the interpretation of gastric ultrasound in horses with colic requires an understanding of these effects. Cranial to caudal and dorsal to ventral ultrasonographic dimensions of the stomach were obtained in 10 unfed horses and five fed horses, before and after nasogastric tube placement, after checking for reflux and after administration of 6 L of water in unfed hors...
Li XB, Huang XX, Li Q, Li XY, Li JH, Li C, He LJ, Jing HX, Yang KL.Compared with the stomach of ruminant cattle, the stomach of horse is small and mainly for chemical digestion, but the microorganisms in the stomach play an important role in maintaining the homeostasis of the internal environment. Due to the complexity of the microbes in the stomach, little is known about the diversity and structure of bacteria in the equine stomach. Grains are the main energy source for plant-eating livestock and energy is derived through enzymatic hydrolysis of grains into glucose or their microbial fermentation into Volatile fatty acids (VFA). However, the mechanism throug...
Poradowski D, Chrószcz A.Histological and morphometrical analysis of the stomach wall was performed during the foetal period divided into three age groups (4th-11th month of gestation). The material was taken from non-glandular (the blind ventricular sac) and glandular parts (the plicated edge margin/cardiac part, the body of stomach and the pyloric part) of the stomach. It was preserved and prepared according to the standard protocol. The histological slides were stained (H-E, Masson-Goldner and PAS). The analyses were performed using the light microscope. All measurements were statistically elaborated. The crown-rum...
Straticò P, Razzuoli E, Hattab J, Guerri G, Celani G, Palozzo A, Bonanni D, Fruscione F, Varasano V, Petrizzi L, Marruchella G.A 7-year-old Friesian stallion with a history of oesophageal stenosis, weight loss, inappetence, and recurrent hyperthermia was referred for gastroscopy. The stomach mucosa surrounding the oesophageal opening showed a large, necrotic, and ulcerated mass. On post-mortem examination, a very large, cauliflower-like neoplasm was seen, affecting non-glandular gastric mucosa. Nodular lesions were observed, scattered on the omentum, the spleen, and the liver. Microscopic findings allowed the diagnosis of gastric squamous cell carcinoma with abdominal metastasis. Biomolecular investigations demonstrat...
Gish A, Robveille C, Gicquel T, Allorge D, Gault G, Gaulier JM.Analytical detection of Oenanthe crocata toxins in biological samples is challenging because of their instability, the lack of commercially available standards and the exceptionally low detection of these molecules using mass spectrometry. This work aims to report the used analytical methods that allowed identification of the main plant toxins in biological samples from an equid (an Arabian horse) fatality related to hemlock water dropwort (Oenanthe crocata Linnaeus) intake. Using both LC-DAD and LC-HRMS methods allowed identification (i) of oenanthotoxin in roots found on the site, root fragm...
Haardt H, Romero AE, Boysen SR, Lohnherr A, Tan JY.Abdominal organ displacement is a potentially life-threatening condition in horses. Primary care veterinarians commonly make referral decisions based on a combination of clinical and ultrasonographic findings. However, published studies describing the effects of transducer on identifying abdominal organ locations in horses are currently lacking. The objective of this prospective, methods comparison, pilot study was to compare organ identification using a high-frequency linear (transrectal) transducer and a low-frequency curvilinear (abdominal) transducer for transcutaneous abdominal ultrasonog...
MacNicol JL, Pearson W. organ culture can provide insight into isolated mucosal responses to particular environmental stimuli. The objective of the present study was to investigate the impact of a prolonged culturing time as well as the addition of acidic gastric fluid into the environment of cultured gastric antral tissue to evaluate how altering the commonly used neutral environment impacted tissue. Furthermore, we aimed to investigate the impact of G's Formula, a dietary supplement for horses, on the secretion of gastrin, interleukin1-beta (IL-1β), and nitric oxide (NO). These biomarkers are of interest due to ...
Lo Feudo CM, Stucchi L, Conturba B, Alberti E, Zucca E, Ferrucci F.Equine squamous gastric disease (ESGD) may require prolonged treatments with acid suppressants; therefore, interest in nutraceutical supplements with anti-ulcerogenic properties has increased. This study aims to investigate the efficacy of Trophogast pellet for the treatment of ESGD in endurance horses. Methods: Fifteen endurance horses were included based on their gastroscopic examination and randomly assigned to a treatment group, receiving Trophogast pellet for 30 days together with management changes, or to a control group, only subjected to management modifications. At the end of treatmen...
Bachmann M, Glatter M, Bochnia M, Greef JM, Breves G, Zeyner A.For a period of 20 days, 12 horses either received a prebiotic supplementation with fructooligosaccharides and inulin via Jerusalem artichoke meal (JAM) or corncob meal without grains (CMG) as placebo. The horses were euthanized 1 hour postprandial, gastric digesta was sampled from pars nonglandularis (PNG) and pars glandularis (PG), and concentrations of starch, mono- and disaccharides, fructans, d- and l-lactic acid, and short chain fatty acids were analyzed. Concentrations of starch and simple sugars were widely the same in JAM supplemented and not supplemented meals. However, fructans were...
Bauck AG, Nelson E, McLain A, Cock G, Sanchez LC, Freeman DE.To describe a modified celiotomy to improve access to cranial abdominal structures in horses. Methods: Four horses. Methods: Short case series. Methods: Three horses with gastric impactions were treated with gastrotomies. One horse was treated for a diaphragmatic hernia with herniorrhaphy and mesh augmentation. In all horses, the ventral midline celiotomy was modified cranially with a J-incision through the body wall, along the paracostal arch. Results: The only surgical complications were midline incisional infections in all horses. Three of the four horses had good long-term outcomes; the re...
Cerri S, Taminiau B, de Lusancay AH, Lecoq L, Amory H, Daube G, Cesarini C.Omeprazole administration is associated with changes in gastric and fecal microbiota and increased incidence of Clostridioides difficile enterocolitis in humans and dogs. Objective: Study purpose was to assess the effect of omeprazole on gastric glandular and fecal microbiota in healthy adult horses. Methods: Eight healthy horses stabled on straw and fed 100% haylage. Methods: Prospective controlled study. Transendoscopic gastric glandular biopsies, gastric fluid, and fecal samples were obtained from each horse twice at a 7-day interval before the administration of omeprazole. Samples were tak...
Jacobs RD, Gordon MBE, Vineyard KR, Keowen ML, Garza F, Andrews FM.Low gastric pH for extended periods of time can increase the risk of gastric ulceration in horses. Therefore, nutritional interventions that buffer stomach acid may be helpful to decrease ulcer risk. The objective of this trial was to evaluate whether the incorporation of calcified Lithothamnion corallioides and Phymatolithon calcareum (Calmin; Celtic Sea Minerals, Cork, Ireland) into an equine ration would buffer equine gastric juice. Nine mature, Thoroughbred-cross horses, including 6 geldings and 3 mares (524 ± 49 kg) were housed in stalls and fed 2 kg/day of a texturized concentrate (Pu...
Porcellato I, Modesto P, Cappelli K, Varello K, Peletto S, Brachelente C, Martini I, Mechelli L, Ferrari A, Ghelardi A, Razzuoli E.In horses, squamous cell carcinomas (SCCs) are the most common malignant tumors developing on non-pigmented skin, muco-cutaneous areas, like external genitalia, and, less frequently, in the stomach. Growing evidence suggests Equus caballus papillomavirus type 2 (EcPV2) as causative agent of genital SCCs. Our case report describes a 20-year-old, female, mixed-breed pony with co-occurring vulvar papilloma and in situ carcinoma and gastric SCC. Both lesions were positive for the same EcPV2, as confirmed by DNA sequencing. E6 mRNA expression was observed both in vulvar lesions and gastric SCC, whi...
Bachmann M, Glatter M, Bochnia M, Wensch-Dorendorf M, Greef JM, Breves G, Zeyner A.Fructooligosaccharides (FOS) and inulin may modulate hindgut fermentation. It was tested if digesta batch cultures taken from horses adapted to FOS and inulin show different fermentation compared with such taken from nonsupplemented horses. Six horses received 0.15 g FOS and inulin/kg body weight/d via Jerusalem artichoke meal (JAM) upon a hay-based diet; six horses received corncob meal without grains (CMG) as placebo. The horses were euthanized after 20 days. Digesta samples were taken from stomach, cecum, ventral colon ascendens (VCA), and colon transversum (CT). Digesta batch cultures we...
Reed L, MacNicol JL, Charchoglyan A, Brewer D, Murrant C, Pearson W.The objective of this study was to evaluate the effect of a botanical-based equine nutraceutical on contractility of gastric smooth muscle in vitro. Gastric ulcers are prevalent in performance horses and negatively impact horse welfare. Gastric hypermotility has been positively associated with the development of gastric ulceration in nonequine species, and reduction of hypermotility may be protective against their development. Stomachs from 12 pigs processed for food at a provincially inspected abattoir were collected within 1 hour of slaughter. Explants of nonglandular gastric tissue were p...
Tyma JF, Epstein KL, Whitfield-Cargile CM, Cohen ND, Giguère S.OBJECTIVE To determine the effects of oral omeprazole administration on the fecal and gastric microbiota of healthy adult horses. ANIMALS 12 healthy adult research horses. PROCEDURES Horses were randomly assigned to receive omeprazole paste (4 mg/kg, PO, q 24 h) or a sham (control) treatment (tap water [20 mL, PO, q 24 h]) for 28 days. Fecal and gastric fluid samples were collected prior to the first treatment (day 0), and on days 7, 28, 35, and 56. Sample DNA was extracted, and bacterial 16S rRNA gene sequences were amplified and sequenced to characterize α and β diversity and differential ...
Lyons ET, Bolin DC, Bryant UK, Cassone LM, Jackson CB, Janes JG, Kennedy LA, Loynachan AT, Boll KR, Burkhardt AS, Langlois EL, Minnis SM, Welsh SC....Parasite infections are more quantifiable postmortem than antemortem in horses. Thus a study was carried out examining dead horses for specific parasite species. Most of the weanling and older horses submitted to the University of Kentucky Veterinary Diagnostic Laboratory (UKVDL) for postmortem examination between November 22, 2016 and March 23, 2017 were examined for certain species of internal parasites. The stomach and duodenum from 69 horses were examined for bots (Gasterophilus spp.). Combined data for both Thoroughbred and non-Thoroughbred (16 other than Thoroughbred breeds/mixed breeds)...
Tesena P, Korchunjit W, Taylor J, Wongtawan T.Gastric tissue biopsy and gene expression analysis are important tools for disease diagnosis and study of the physiology of the equine stomach. However, RNA extraction from gastric biopsy samples is a complex procedure because the samples contain low quantities of RNA and are contaminated with mucous protein and bacterial flora. The objectives of these studies were to compare the performance of RNA extraction methods and to investigate the sensitivity of commercial qPCR master mixes for gene expression analysis of gastric biopsy samples. Three commercial RNA extraction methods (TRIzol, GENEzol...
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...
Perkins GA, den Bakker HC, Burton AJ, Erb HN, McDonough SP, McDonough PL, Parker J, Rosenthal RL, Wiedmann M, Dowd SE, Simpson KW.Little is known about the gastric mucosal microbiota in healthy horses, and its role in gastric disease has not been critically examined. The present study used a combination of 16S rRNA bacterial tag-encoded pyrosequencing (bTEFAP) and fluorescence in situ hybridization (FISH) to characterize the composition and spatial distribution of selected gastric mucosal microbiota of healthy horses. Biopsy specimens of the squamous, glandular, antral, and any ulcerated mucosa were obtained from 6 healthy horses by gastroscopy and from 3 horses immediately postmortem. Pyrosequencing was performed on bio...
Yuki N, Shimazaki T, Kushiro A, Watanabe K, Uchida K, Yuyama T, Morotomi M.Selective adhesion to only certain epithelia is particularly common among the bacterial members of the indigenous microflora of mammals. We have found that the stratified squamous epithelium of the nonsecreting area of horse stomach is colonized by gram-positive rods. The microscopic features of a dense layer of these bacteria on the epithelium were found to be similar to those reported in mice, rats, and swine. Adhering microorganisms were isolated and identified as Lactobacillus salivarius, L. crispatus, L. reuteri, and L. agilis by DNA-DNA hybridization and 16S rRNA gene sequencing techniqu...
Lorenzo-Figueras M, Merritt AM.To assess effects of exercise on a treadmill with changes in gastric volume and pH in the proximal portion of the stomach of horses. Methods: 3 healthy adult horses. Methods: A polyester bag of approximately 1,600 mL was placed into the proximal portion of the stomach of each horse via a nasogastric tube. Changes in bag volume, determined by an electronic barostat, were recorded before, during, and after a training session on a treadmill with and without prior withholding of food. In separate experiments, pH in the proximal portion of the stomach was continuously recorded during exercise for f...
Bell RJ, Kingston JK, Mogg TD, Perkins NR.To establish the prevalence and factors influencing the prevalence and severity of gastric ulceration in racehorses in New Zealand. Methods: Horses (n=171) in active training for racing by trainers (n=24) located throughout New Zealand were examined using gastroscopy during 2003 and 2004. Images of the examination were recorded and reviewed, and an ordinal grade based on the severity of gastric ulceration present was assigned, using the grading system proposed by the Equine Gastric Ulcer Council (EGUC). Information about the horses such as age, breed, sex, stabling, time at pasture, pasture qu...
Nieto JE, Snyder JR, Beldomenico P, Aleman M, Kerr JW, Spier SJ.Gastric endoscopy was performed at the end of a 50 or 80 km endurance ride. Gastric ulceration was evident in 67% of the horses with ulcers on the squamous region of the stomach found in 57% of the horses and active bleeding of the glandular mucosa in 27%. Three horses (10%) had lesions only on the glandular mucosa. Values of albumin, creatinine and glucose were higher in horses without gastric lesions. We conclude that horses from endurance competitions have a high prevalence of gastric ulceration that is similar to that observed in performance horses. However the severity of ulceration is le...
Bell RJ, Mogg TD, Kingston JK.In recent years, gastric ulceration has been recognised as a common, possibly performance-limiting disease of adult horses. Here, we aim to provide the reader with a useful review of recent literature covering all aspects of equine gastric ulcer syndrome (EGUS) in adult horses. The anatomy and physiology of the stomach, with particular reference to secretion of acid and mucosal protective mechanisms, are reviewed, as are the differing theories relating to the aetiopathogenesis of gastric ulceration. We also explore the possible influence of various management factors on development of the dise...
MacAllister CG, Andrews FM, Deegan E, Ruoff W, Olovson SG.Five investigators familiar with gastric ulcer disease in horses met to establish a scoring system that could be utilised in future studies. Slides of gastric lesions were viewed and discussed and a scoring system established that required the nonglandular and glandular portions of the stomach to be graded separately. Each portion of the stomach (glandular and nonglandular) received a score for number of ulcers present and a score for severity of ulcers which resulted in each stomach receiving 4 separate scores. After the grading system was developed, each investigator independently graded 16 ...
Kitamura N, Yamada J, Calingasan NY, Yamashita T.Endocrine cells immunoreactive for somatostatin, gastrin, glicentin, glucagon, secretin, cholecystokinin, motilin and neurotensin were identified immunocytochemically in the gastrointestinal mucosa of the horse. Somatostatin-, glicentin- and glucagon-immunoreactive cells were very numerous in the cardiac and fundic regions of the stomach, whereas most gastrin-immunoreactive cells were confined to the pyloric region. Somatostatin-immunoreactive cells also were detected in all portions of the small intestine while gastrin-immunoreactive cells were confined exclusively to the upper portion and gl...
Dancker C, Hopster K, Rohn K, Kästner SB.In the horse, effects of cardiovascular-active drugs on local perfusion of the gastrointestinal tract are poorly understood. Objective: To determine the effect of drugs commonly used to support blood pressure, on local intestinal blood flow and tissue oxygenation under isoflurane anaesthesia. Methods: In vivo randomised crossover experiment. Methods: Ten horses were anaesthetised with isoflurane. After 90 min of equilibration three doses (μg/kg bwt/min) of dobutamine (DOB 0.5/1/3), dopamine (DA 1/2/5), noradrenaline (NA 0.1/0.2/0.5) and phenylephrine (PHE 0.5/1/3) were infused for 15 min, in ...
Nadeau JA, Andrews FM, Patton CS, Argenzio RA, Mathew AG, Saxton AM.To identify in vitro effects of hydrochloric acid, valeric acid, and other volatile fatty acids (VFAs) on the pathogenesis of ulcers in the nonglandular portion of the equine stomach. Methods: Gastric tissues from 13 adult horses. Methods: Nonglandular gastric mucosa was studied by use of Ussing chambers. Short-circuit current (Isc) and potential difference were measured and electrical resistance and conductance calculated after tissues were bathed in normal Ringer's solution (NRS) or NRS and hydrochloric, valeric, acetic, propionic, and butyric acids. Treated tissues were examined histologica...
Murray MJ, Nout YS, Ward DL.Medical records and endoscopy images were examined for 209 horses that had gastroscopic examinations performed with a 2.5- or 3-m-long endoscope by one of the authors (MJM) during a 4-year period (1996-2000). The antrum and pylorus were viewed in 162 horses, and the duodenum was viewed in 94 horses. Of these 162 horses, the gastric squamous mucosa was seen in 157 horses and 50% or more of the glandular mucosa of the body of the stomach was seen in 156 horses. Erosions or ulcers were seen in the gastric squamous mucosa in 91 (58%) horses. Erosions or ulcers were seen in the glandular mucosa of ...
Tyma JF, Epstein KL, Whitfield-Cargile CM, Cohen ND, Giguère S.OBJECTIVE To determine the effects of oral omeprazole administration on the fecal and gastric microbiota of healthy adult horses. ANIMALS 12 healthy adult research horses. PROCEDURES Horses were randomly assigned to receive omeprazole paste (4 mg/kg, PO, q 24 h) or a sham (control) treatment (tap water [20 mL, PO, q 24 h]) for 28 days. Fecal and gastric fluid samples were collected prior to the first treatment (day 0), and on days 7, 28, 35, and 56. Sample DNA was extracted, and bacterial 16S rRNA gene sequences were amplified and sequenced to characterize α and β diversity and differential ...
Murray MJ, Schusser GF.A glass combined pH-reference electrode was placed in the stomachs of 5 adult horses and pH was recorded every 6 mins for 24 h while (1) feed and all bedding materials were withheld for 24 h (unfed), (2) horses had free access to Timothy grass hay for 24 h (fed), and (3) horses had free access to Timothy grass hay and were treated with ranitidine, 6.6 mg/kg body weight, orally, every 8 h for 48 h (fed + ranitidine). There was a significant (P = 0.007) difference in median 24-h gastric pH amongst the 3 protocols, the value being 3.1 in fed horses and 1.55 in unfed horses (P = 0.05) and 4.6 in f...
Husted L, Sanchez LC, Olsen SN, Baptiste KE, Merritt AM.Stall housing has been suggested as a risk factor for ulcer development in the equine stomach; however, the exact pathogenesis for this has not been established. Objective: To investigate the effect of 3 environmental situations (grass paddock, stall alone or stall with adjacent companion) on pH in the proximal and the ventral stomach. Methods: Six horses with permanently implanted gastric cannulae were used in a randomised, cross-over, block design. Each horse rotated through each of three 24 h environmental situations. Horses remained on their normal diet (grass hay ad libitum and grain b.i....
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...
Husted L, Jensen TK, Olsen SN, Mølbak L.The equine glandular stomach is commonly affected by erosion and ulceration. The aim of this study was to assess whether bacteria, including Helicobacter, could be involved in the aetiology of gastric glandular lesions seen in horses. Results: Stomach lesions, as well as normal appearing mucosa were obtained from horses slaughtered for human consumption. All samples were tested for urease activity using the Pyloritek assay, while mucosal bacterial content was evaluated using Fluorescence In Situ Hybridisation. In selected sub samples, bacteria characterisation was pursued further by cloning an...
Sequeira JL, Tostes RA, Oliveira-Sequeira TC.The objective of the present study was to investigate the prevalence of Gasterophilus nasalis larvae in Botucatu, the central west region of São Paulo State, Brazil, and to describe the lesions caused by the parasite. The climate of Botucatu is warm and rainy during the months of December through March and cool and dry during the months of May through August. The prevalence of G. nasalis was 16.84%, and the period of peak infestation corresponded to the months of cold and dry weather. The lesions detected at the sites of larval attachment were examined macro- and microscopically. Erosions and...
Kivett L, Taintor J, Wright J.Simultaneous administration of a nonselective COX inhibitor and a COX-2 specific NSAID has not been previously reported in horses. The goal of this study was to determine the safety of a 10-day dosage regimen of phenylbutazone and firocoxib, both at their standard dosages, in horses. Six horses were administered 2.2 mg/kg of phenylbutazone and 0.1 mg/kg of firocoxib by mouth, daily for 10 days. Horses were assessed daily for changes in behavior, appetite, fecal consistency, signs of abdominal pain, and oral mucous membrane ulceration. Horses were assessed prior to and on the last day of treatm...
le Jeune S, Whitcomb MB.Abdominal ultrasound is an invaluable aid in the evaluation of the colic patient but can be heavily influenced by patient preparation, individual horse-to-horse variation, availability of ultrasound transducers, technique, experience level of the examiner, and complexity of the abdominal disorder. This article describes ultrasonographic anatomy of the normal equine abdomen and technique for examination of the equine colic patient. Common abnormalities of the stomach, small intestine, large intestine, and peritoneal cavity are described along with other abnormalities that may be discovered with...
Lester GD, Smith RL, Robertson ID.To compare the effects of oral administration of omeprazole and ranitidine on gastric squamous ulceration in Thoroughbreds in race training. Methods: Modified crossover study. Methods: 60 Thoroughbreds in race training with gastric squamous mucosal ulceration. Methods: Horses were randomly allocated into 3 groups. Group 1 received no treatment for 28 days followed by administration of omeprazole (4 mg/kg [1.8 mg/lb], PO, once daily) for 28 days; group 2 received omeprazole (4 mg/kg, PO, once daily) for 28 days followed by no treatment for 28 days; and group 3 received ranitidine (6.6 mg/kg [3....
Naem S.Drashia megastoma Rudolphi, 1819, Habronema muscae Carter, 1861 and Habronema microstoma Schneider, 1866 are found in the stomach of equine definitive hosts and are known to cause pathogenic effects in the stomach wall, skin, eye and occasionally other sites. These nematodes utilise either house flies or stable flies as their intermediate hosts. Apart from molecular findings that have demonstrated some of the differences between H. muscae and H. microstoma, no detailed morphological description of equine habronematid nematodes has been presented. This article describes most surface features of...
Naem S.Habronema muscae (Spirurida: Habronematidae) occurs in the stomach of equids, is transmitted by adult muscid dipterans and causes gastric habronemiasis. Scanning electron microscopy (SEM) was used to study the morphological aspects of adult worms of this nematode in detail. The worms possess two trilobed lateral lips. The buccal cavity was cylindrical, with thick walls and without teeth. Around the mouth, four submedian cephalic papillae and two amphids were seen. A pair of lateral cervical papillae was present. There was a single lateral ala and in the female the vulva was situated in the mid...
Borgsteede FH, van Beek G.The prevalence of metazoan parasites in the stomach and small intestine was investigated in 70 horses slaughtered in the period February 1994-July 1994. Most horses were young (1.5-3 years) and in good condition. Trichostrongylus axei was the most prevalent parasite species in the stomach (51.4%), followed by Gasterophilus intestinalis (41.4%) and Habronema spp. (4.3%). In the small intestine, Parascaris equorum (28.6%) and Paranoplocephala mamillana (1.4%) were found. The mean worm burden of T. axei was 957 (max. 8502), of G. intestinalis 21 (max. 84), of Habronema spp. 3 (max. 5), and of P. ...
Bezdekova B, Jahn P, Vyskocil M.Gastroduodenal ulceration is a prevalent disease in foals and adult horses. Decreased performance as well as fatal complications relate to this syndrome. The objective of our study was to determine the prevalence of gastric ulceration in a mixed population of horses by postmortem examination and to evaluate a possible association between equine gastric ulcer syndrome (EGUS) and sex or age of the examined horses, to evaluate the localisation of lesions in the proximal part of the gastrointestinal tract and to determine the occurrence of gastric parasites. Postmortem examinations were performed ...
D'Arcy-Moskwa E, Noble GK, Weston LA, Boston R, Raidal SL.Newer NSAIDs that more selectively target the induced isoform of the cyclooxygenase enzyme (COX2) activity might reduce adverse effects while preserving therapeutic benefits of these drugs. Objective: To compare the effect of oral administration of multiple dose rates of meloxicam and phenylbutazone (PBZ) on gastric mucosal integrity in horses. Methods: Twenty-five light breed horses. Methods: In vivo toxicity study. Horses were randomly assigned to 5 treatment groups, receiving placebo, PBZ (4.4 mg/kg PO q12h day 1, 2.2 mg/kg PO q12h for 4 days, 2.2 mg/kg PO q24h for 9 days), or 3 dose rates ...
Cerri S, Taminiau B, de Lusancay AH, Lecoq L, Amory H, Daube G, Cesarini C.Omeprazole administration is associated with changes in gastric and fecal microbiota and increased incidence of Clostridioides difficile enterocolitis in humans and dogs. Objective: Study purpose was to assess the effect of omeprazole on gastric glandular and fecal microbiota in healthy adult horses. Methods: Eight healthy horses stabled on straw and fed 100% haylage. Methods: Prospective controlled study. Transendoscopic gastric glandular biopsies, gastric fluid, and fecal samples were obtained from each horse twice at a 7-day interval before the administration of omeprazole. Samples were tak...
Lyons ET, Tolliver SC, Drudge JH, Swerczek TW, Crowe MW.A total of 278 Thoroughbreds (less than 1 to 31 years old) were examined at necropsy (July 9, 1985, to Feb 2, 1986) in Kentucky for various internal parasites. Examination was not made of all the horses for each of the parasites. Specific parasites recovered from the stomach of foals (n = 30) and yearlings and older horses (n = 96) and percentage (in parentheses) of each age category infected, respectively, were as follows: Gasterophilus intestinalis 2nd instar (53% and 32%) and 3rd instar (37% and 24%); G nasalis 2nd instar (7% and 8%) and 3rd instar (7% and 10%); Habronema spp immature (7% a...
