Equine Gastric Ulcer Syndrome Research Articles

Equine Gastric Ulcerative Syndrome in a population of horses at Antioquia: Frequency and risk factors

Background: Equine gastric ulcer syndrome (EGUS) has been associated with duration of confinement, grain supplementation, exercise, stress, use of non-steroidal anti-inflammatory drugs, and the gastric microbiome. On the other hand, limited information is available on the risk factors for EGUS in Colombia. Objective: To determine the frequency and risk factors for the presentation of EGUS in several municipalities of Antioquia. Methods: A total of 103 male and female horses were evaluated. Endoscopic samples from different portions of the stomach were taken and subjected to histopathological analysis. Information on management conditions for each animal was also obtained. Descriptive statistics, association analysis and logistic regression were performed. Results: A 69% of the animals presented at least one gastric lesion: 22.3% lesions in the squamous mucosa, 39.2% in the Margo plicatus (MP) and 48.9% in the glandular region. Diet was associated with the presentation of ulcers in the squamous mucosa (p = 0.003). MP ulceration was associated with concentrate feed consumption (p = 0.032). Conclusion: The EGUS frequency is 69%. Consumption of concentrate feed by horses in Antioquia is a critical factor for the development of ulcers in the stomach squamous and glandular regions.

Equine gastric ulcer syndrome (EGUS). Prevalence, etiology, diagnostic

The analysis of scientific literature and different studies of recent years concerning diseases of the stomach in horses has been conducted in the article. The analysis of literature data indicates that the Equine gastric ulcer syndrome is a common disease especially among racehorses. This term is a condition in horses, characterized by ulcers in the terminal esophagus; proximal (squamous) stomach; distal (glandular) stomach; and proximal duodenum. The anatomy and physiology of the stomach, with particular reference to secretion of acid and mucosal protective mechanisms, are reviewed as well as the differing theories relating to the aetiopathogenesis of gastric ulceration. The prevalence of the disease in racehorses has been reported from 60 to 90%. In general, horses that are in active training for racing tend to have a prevalence of around 90%, whereas horses for pleasure in full work have a reported prevalence of approximately 60%. The recent years data indicate the influence of microorganism Helicobacter genus on ulceration in equine stomach, a new specific species of H. Equorum was identified by the PCR assay in horse faeces, but the relationship between different species of Helicobacter and stomach ulcers remains controversial. Recently, nutritional and dietary management factors, the features of the anatomical structure of the stomach, dental problems, nonsteroidal anti-inflammatory drugs etc. have been identified to play an important role in gastric ulceration in horses. Clinical signs of EGUS are not always noticeable. Depending on the degree of damage, сlinical signs in horses with EGUS include: acute and recurrent colic, poor body condition, partial anorexia, poor appetite, poor performance and attitude changes, diarrhea,, the disease is accompanied by weight loss, loss of appetite and decreased ability to work. This disease affects the physical condition of horses, slows the growth and development of foals. The introduction of new diagnostic tests and methods in veterinary practice, including gastroscopy, allows to diagnose ulcers on early stages, investigate and explore the causes of EGUS. The diagnosis requires a thorough treatment history, physical examination, and a minimum database. Identifying risk factors and clinical signs are also helpful in making a diagnosis. However, gastroscopy is the only definitive diagnosis for gastric ulcers currently available. in more detail. The article presents a 0‒5 gastric ulcer scoring system to determine a lesion prevelence.

Re-evaluation of the regulation of omeprazole in racehorses: An evidence-based approach.

Medication control and doping control have been established in horse racing to ensure the integrity of the sport and the welfare of the horses. This ensures that horses do not compete under the influence of any drugs, including omeprazole, a therapeutic medication used to treat equine gastric ulcer syndrome. In this study, pharmacokinetic data were produced in equine plasma and urine following an oral administration of 4mg/kg of generic buffered formulation of omeprazole to six Thoroughbred horses in five daily doses to determine an appropriate screening limit and detection time in equine plasma and to assess whether the current detection time of 72hr in equine urine would be applicable when an alternative omeprazole product is administered. Cmax of 436-2,432ng/ml and AUC0-tau of 1,476-4,371nghrml-1 were obtained for plasma and indicated, in conjunction with other published oral omeprazole studies, that an appropriate plasma screening limit would be 500pg/ml with a detection time of 48hr. Urine analysis showed that omeprazole could be detected for up to 25hr above the previously established urine screening limit of 500pg/ml and thus indicated that the detection time advice could be potentially reduced from 72 to 48hr to allow more comprehensive treatment of gastric lesions.

Courses for horses: Rethinking the use of proton pump inhibitors in the treatment of equine gastric ulcer syndrome

SummaryOral omeprazole has been the cornerstone of equine gastric ulcer syndrome (EGUS) treatment for nearly 20 years. However, approximately 15–30% of equine squamous gastric disease (ESGD) cases and 75% of equine glandular gastric disease (EGGD) cases fail to heal within current treatment guidelines. Recently, a number of factors that may affect the efficacy of oral omeprazole have been highlighted and the pharmacodynamics of a number of novel proton pump inhibitors (PPIs) have been described in the horse. The purpose of this article is to review the factors that affect oral omeprazole efficacy, with the goal of maximising therapeutic response, and the novel PPIs recently described.

First demonstration of equid gammaherpesviruses within the gastric mucosal epithelium of horses

Horses commonly develop gastric mucosal ulcers, similar to humans, a condition known as equine gastric ulcer syndrome (EGUS) that can lead to poor performance and lost training time and care expenses. Unlike humans, however, an infectious bacterial cause of ulcers has not been conclusively identified. Herpesviruses, while well-established causative agents of diseases such as cold sores, genital lesions, and certain types of cancer, have also been implicated in the development of a subset of gastric ulcers in humans. The presence of equid herpesviruses in the gastrointestinal tract and their potential contribution to EGUS has not been evaluated. Here, we provide the first evidence of equid gammaherpesviruses 2 and 5 (EHV-2 and -5) within the epithelium of the gastric mucosa of horses. These viruses were initially detected by a nested PCR screen of gastric tissue samples obtained from client- and university-owned horses with and without ulcers; however, no association with EGUS was found in this limited sample set. We then validated a highly sensitive in situ hybridization (ISH) assay and used this assay to characterize the distribution of these viruses in necropsy gastric tissue samples from five racehorses. Analyses revealed frequent EHV-2 and EHV-5 co-infections within the gastric mucosal epithelium, regardless of the ulcer status. These results are the first to demonstrate the presence of equid gammaherpesviruses in the gastric mucosa of horses and warrants further investigation to determine the contribution of these viruses to the development of EGUS and/or other gastrointestinal diseases.

Increased adrenocortical response to adrenocorticotropic hormone (ACTH) in sport horses with equine glandular gastric disease (EGGD)

This study tested the hypothesis that adrenocortical function would be altered in horses with equine gastric ulcer syndrome (EGUS). Twenty-six sport horses competing at national or international levels in eventing (n=15) or endurance (n=11) were subjected to a gastroscopic examination and an adrenocorticotropic hormone (ACTH) stimulation test. Salivary cortisol concentrations were measured before (baseline) and after (30, 60, 90, 120 and 150min) IV ACTH injection (1μg/kg bodyweight). Within EGUS, two distinct diseases, equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD), can be distinguished.ESGD was diagnosed in 8/11 (73%; 95% confidence intervals [95%CI], 43–92%) endurance horses and 5/15 (33%; 95% CI, 14–58%) eventing horses. EGGD was observed in 9/11 (82%; 95% CI, 53–96%) endurance horses and 9/15 (60%; 95% CI, 35–81%) eventing horses. The presence or severity of ESGD was unrelated to the presence or severity of EGGD. ACTH stimulation induced a larger increase in cortisol concentration in horses with moderate EGGD than in horses with mild EGGD. Cortisol concentration during the entire sampling period (total increase in cortisol concentration during the entire sampling period [dAUC], 31.1±6.4ng/mL) and the highest measured concentration at a single time point (maximal increase in cortisol concentration [dMAX], 10.3±2.3ng/mL) were increased (P=0.005 and P=0.038, respectively), indicating that horses with glandular gastric disease exhibited increased adrenocortical responses to ACTH stimulation. These results suggest that EGGD might be associated with an enhanced adrenocortical sensitivity. Further investigations are warranted to confirm the association between adrenocortical sensitivity and EGGD and to elucidate the pathophysiological mechanisms involved.

Oral Esomeprazole As A Treatment For Equine Gastric Ulcer Syndrome Refractory To Oral Omeprazole

Oral Esomeprazole As A Treatment For Equine Gastric Ulcer Syndrome Refractory To Oral Omeprazole

Comparison of aloe vera and omeprazole in the treatment of equine gastric ulcer syndrome.

Anecdotally, aloe vera is used to treat gastric ulceration, although no studies have yet investigated its efficacy in horses. To test the hypothesis that aloe vera would be noninferior to omeprazole in the treatment of equine gastric ulcer syndrome. Randomised, blinded clinical trial. Forty horses with grade ≥2 lesions of the squamous and/or glandular mucosa were randomly assigned to one of two groups. Horses received either aloe vera inner leaf gel (17.6 mg/kg bwt) b.i.d. or omeprazole (4 mg/kg bwt) s.i.d. for approximately 28 days, after which a repeat gastroscopic examination was performed to determine disease resolution. Horses with persistent lesions were offered a further 28 days of treatment with omeprazole (4 mg/kg bwt s.i.d.) and were re-examined on completion of treatment. Efficacy analyses were based on 39 horses that completed the trial. Equine squamous gastric disease (ESGD) was observed in 38 horses; improvement and healing rates in these horses were 56% and 17%, respectively, in the aloe vera group, and 85% and 75%, respectively, in the omeprazole group. Healing was less likely to occur in horses with prolonged gastric emptying. Equine glandular gastric disease (EGGD) was less common than ESGD (n = 14) and numbers were too small to perform meaningful statistical analyses. The hypothesis that aloe vera would be noninferior to omeprazole was not supported. No placebo control group was included. Limited numbers preclude any comment on the efficacy of aloe vera in the treatment of EGGD. Treatment with aloe vera was inferior to treatment with omeprazole.

Crib Biting And Equine Gastric Ulceration Syndrome, Is There An Anatomical Link?

Crib Biting And Equine Gastric Ulceration Syndrome, Is There An Anatomical Link?

Clinical nutrition counselling service in the veterinary hospital: retrospective analysis of equine patients and nutritional considerations.

Nutrition plays a very important role in the healthy and in the ill horse. Although research in this field clearly shows that incorrect nutritional practices may lead to severe pathologies, inappropriate feeding plans often continue to be used. A clinical nutrition counselling (CNC) service could thus be of great use to both horse owners and veterinarians. The aim of this study was to provide information on equine patients referred to the CNC service of the University of Turin and to provide standard dietary protocols as used in our Veterinary Teaching Hospital for the most common nutrition-related pathologies. The data were obtained by retrospective analysis of the nutritional records of referred equine patients. The data collected included information about anamnesis, nutritional assessment, current diet, referring person and follow-up of each patient. Sixty-one horses were included in the study. The majority were adult males. The most common breeds were the Italian Saddle Horse and the Friesian Horse. Old horses (>19years) had a statistically lower BCS than brood mares or other adult horses (p<0.01). The most common nutritional pathologies were chronic weight loss (CWL), chronic diarrhoea (CD) and equine gastric ulcer syndrome. All horses received first-cut meadow hay; 85% also ate concentrates. Young horses (<2years) received more hay as a percentage of body weight (BW) than old horses or adults. The hay percentage of BW per day given to animals with CWL was statistically higher than those with CD (p<0.01). The concentrate percentage of BW given to old horses was statistically lower compared to that given to young horses (p<0.05). The concentrate percentage of BW per day given to horses with colic was statistically higher than that given to horses with CD (p<0.05). 28% of cases were referred by the owner and 72% by a veterinarian. Follow-up evaluation was deemed to be 'good' in 92% cases and 'poor' in 8%. In summary, the CNC service could provide an epidemiological observatory to study the prevalence of nutritional issues in the equine population.

Equine gastric ulcer syndrome in adult donkeys: Investigation on prevalence, anatomical distribution, and severity

SummaryThe study was performed on 39 live donkeys that underwent gastroscopic examination. The lesions were recorded in accordance with the European College of Equine Internal Medicine Consensus Statement guidelines. The presence of Gasterophilus sp. larvae was also recorded. Larvae were collected and identified to species level. Fisher's exact test was used to compare different prevalence values for sex, age, and anatomical distribution of lesions. Gastric lesions were present in 20/39 (51.3% [35.6–67%]) donkeys; 19/39 (48.7% [95% confidence interval = 33–64.4%]) were affected only by equine squamous gastric disease (ESGD), while 1/39 (2.6% [0–7.5%]) showed both ESGD and equine glandular gastric disease (EGGD), thus 95% of positive donkeys showed lesions located in the nonglandular mucosa. The ESGD grade was 0/4 (48.7% [33–64.4%]) in 19/39, 1/4 (12.8% [2.3–23.3%]) in 5/39, 2/4 (25.6% [11.9–39.5%]) in 10/39, 3/4 in 4/39 (10.3% [0.7–19.8%]) and 4/4 in 1/39 (2.6% [0–7.5%]) donkeys, respectively. The EGGD lesion was a mild depression in the ventral glandular fundus. ESGD was primary in all the donkeys included and lesions were located around the cardia and along the lesser curvature. Gasterophilus sp. larvae were present in all animals and were identified as third‐stage larvae of Gasterophilus intestinalis. No animals showed clinical signs of equine gastric ulcer syndrome (EGUS). No significant differences relating to sex, age or breed were found in the prevalence of EGUS in this study, while the proportion of donkeys affected by ESGD was statistically higher than those affected by EGGD. To the best of our knowledge, this is the first report on the gastroscopic evaluation of EGUS in live donkeys. Our results show a higher prevalence of EGUS in live donkeys than values previously reported by other authors in donkeys that were dead or had been subjected to euthanasia. The detection of third‐stage G. intestinalis larvae was not unexpected since these can be found in the stomach of equids throughout the year, and G. intestinalis has been reported as the most common Gasterophilus sp. in Italy.

Diagnostic accuracy of blood sucrose as a screening test for equine gastric ulcer syndrome (EGUS) in adult horses

BackgroundEquine gastric ulcer syndrome (EGUS) is common in adult horses, particularly those involved in performance disciplines. Currently, detection of EGUS by gastroscopy is the only reliable ante mortem method for definitive diagnosis; however it is unsuitable as a screening test because it is expensive, time consuming, and is not readily available to most veterinarians. Sucrose permeability testing represents a simple, economical alternative to gastroscopy for screening purposes, and the feasibility of this approach in the horse has been previously reported. The aim of this study was to determine the diagnostic accuracy of blood sucrose as a screening test for EGUS in a large group of adult horses with and without naturally occurring gastric disease.ResultsOne hundred and one adult horses with or without naturally occurring gastric ulceration were studied. The diagnostic accuracy of blood sucrose for diagnosis of gastric lesions (GL), glandular lesions (GDL), squamous lesions (SQL), and clinically significant lesions (CSL) at 45 and 90 min after administration of 1 g/kg of sucrose via nasogastric intubation was assessed using receiver operator characteristics (ROC) curves and calculating the area under the curve (AUC). For each lesion type, sucrose concentration in blood was compared to gastroscopy, as the gold standard, and sensitivities (Se) and specificities (Sp) were calculated across a range of sucrose concentrations. Ulcer grading was performed blindly by one observer; and the results were validated by comparing them with that of two other observers, and calculating the level of agreement. Cut-off values were selected manually to optimize Se. The prevalence of GL, GDL, SQL, and CSL was 83, 70, 53 and 58% respectively. At the selected cut-offs, Se ranged from 51 to 79% and Sp ranged from 43 to 72%, depending upon the lesion type and time of sampling.ConclusionsBlood sucrose is neither a sensitive or specific test for detecting EGUS in this population of adult horses with naturally occurring gastric ulceration. Further studies aimed at evaluating the performance characteristics of the test in different study populations are warranted. Given the limitations of endoscopy, due consideration should also be given to alternative methods for comparison of blood sucrose with a gold standard.

Efficacy of the Administration of a Natural Feed Supplement in the Management of Equine Gastric Ulcer Syndrome in 7 Sport Horses: A Field Trial

Equine Gastric Ulcer Syndrome (EGUS) is one of the most common causes of poor performance in the equine patient and affects more than 90% of Standardbred and Thoroughbred racehorses in training. Nowadays, the principal therapeutic options for EGUS treatment include antiacids such as histamine receptor antagonists and proton pump inhibitors. Recently, many studies concerning feed supplements to treat and prevent EGUS were carried out. The aim of the present study was to evaluate the efficacy of a natural feed supplement, administered for 30 days, as the only treatment for gastric ulcerations in sport horses in training. Seven horses were selected for the study on the basis of their gastroscopic evidence of erosive and ulcerative lesions of the gastric mucosa. Each horse received a natural feed supplement (Gastrocure, Institute Farmaceutico Candioli, Italy) registered for use in horses for 30 days. Gastroscopy was performed on day 0 (T1), day 15 (T2) and at the end of the treatment (day 30, T3). Scores were assigned according to MacAllister method (score 0,1,2,3,4 for number of lesions and score 0,1,2,3,4,5 for lesion severity). Statistical analysis showed a strong evidence (p<0.01) of lower scores occurring at T3 when compared to T1for both number and severity of gastric lesions. In conclusion, the administration of Gastrocure was effective in reducing the number and severity of ulcerative lesions in horses affected by EGUS.

PHyloGASTRO in the Treatment of Equine Gastric Ulcer Lesions

Equine gastric ulcer syndrome (EGUS) is the most common disease of the equine stomach with high prevalence of both squamous and glandular disease reported in various populations. The aim of this study was to evaluate the effectiveness of a phytotherapic compound (pHhyloGASTRO) in the therapy of EGUS. The study was performed as a randomized double-blinded single-center study. The study population was composed of 19 equids which were submitted to gastroscopy before and after a 6-week treatment with feed additive (10/19) (pHyloGASTRO, 4Union B.I.O. srl, Italy) or a placebo (9/19). Severity grade was evaluated on a scale from 0 to 4. The variables of interest were gastric lesion score and improvement grade. Changes and comparisons of variables were performed by contingency table analyses. P level of significance was set at .05 in all analyses. In terms of gastric lesion scores, the treated group improved significantly compared to the placebo group. pHyloGASTRO seems to be effective in the treatment of EGUS. Further studies are needed to verify whether prolonged administration of pHyloGASTRO could be more effective in completely healing gastric lesions.

Treatment and prevention of equine gastric ulcer syndrome

Lizzie Leonard-Appleton, Junior Product Manager at Norbrook Laboratories (GB), discusses the strategic role of omeprazole in treating equine gastric ulcer syndrome

Diversity of the Gastric Microbiota in Thoroughbred Racehorses Having Gastric Ulcer.

Equine gastric ulcer syndrome is one of the most frequently reported diseases in thoroughbred racehorses. Although several risk factors for the development of gastric ulcers have been widely studied, investigation of microbiological factors has been limited. In this study, the presence of Helicobacter spp. and the gastric microbial communities of thoroughbred racehorses having mild to severe gastric ulcers were investigated. Although Helicobacter spp. were not detected using culture and PCR techniques from 52 gastric biopsies and 52 fecal samples, the genomic sequences of H. pylori and H. ganmani were detected using nextgeneration sequencing techniques from 2 out of 10 representative gastric samples. The gastric microbiota of horses was mainly composed of Firmicutes (50.0%), Proteobacteria (18.7%), Bacteroidetes (14.4%), and Actinobacteria (9.7%), but the proportion of each phylum varied among samples. There was no major difference in microbial composition among samples having mild to severe gastric ulcers. Using phylogenetic analysis, three distinct clusters were observed, and one cluster differed from the other two clusters in the frequency of feeding, amount of water consumption, and type of bedding. To the best of our knowledge, this is the first study to investigate the gastric microbiota of thoroughbred racehorses having gastric ulcer and to evaluate the microbial diversity in relation to the severity of gastric ulcer and management factors. This study is important for further exploration of the gastric microbiota in racehorses and is ultimately applicable to improving animal and human health.

Nutritional management of gastric ulceration

SummaryGastric ulcers are common in horses and equine gastric ulcer syndrome describes ulcers in the distal oesophagus, nonglandular and glandular stomach as well as the proximal duodenum. Ulcers in the distal oesophagus and nonglandular region of the stomach are probably caused by hydrochloric acid, whereas ulcers in the glandular stomach and proximal duodenum are likely to be caused by a breakdown in the mucosal defence mechanisms. Regardless of the location of ulcers, initial treatment with pharmacological agents is necessary to suppress hydrochloric acid; however, nutrition and management changes are required to maintain ulcer healing and help prevent recurrence. In addition, many dietary supplements have been marketed to help maintain stomach health and some scientific data on their effects on gastric ulcer scores and gastric juice pH are presented.

Gastric juicepHmeasurement in horses: Three‐quarters of a century of history!

SummaryInhibition of gastric acid and increased stomachpH&gt;4.0 is currently accepted as the mainstay of treatment for gastric ulcers in horses. Measurement of gastricpHis complicated and requires placement of a cannula and collection of gastric juice or placement ofpHelectrodes in the stomach. Since the distance from the nares to the stomach is approximately 200 cm, finding a system with apHelectrode with this length is difficult, not to mention difficult to maintain. There has been a fascination with the measurement of gastric juicepHin horses that has covered three‐quarters of a century starting with a fistula model in 1933 and culminating in a recent technique described in this issue. Placement of gastric cannulas and variouspHelectrodes have been used to measure gastric juicepHin horses in the past and present, but the future may require more sophisticated methods as we look at the efficacy of different formulations of acid suppressive drugs for treatment of equine gastric ulcer syndrome.

A comparison of the prevalence of gastric ulceration in feral and domesticated horses in theUK

SummaryEquine gastric ulcer syndrome is common in domesticated horses, especially those performing in athletic endeavours. However, the prevalence of equine gastric ulcer syndrome in feral populations of horses is not documented. This study investigated the prevalence and severity of squamous and glandular gastric ulceration in an abattoir population of horses in theUK. Both squamous and glandular ulceration were more prevalent in domesticated horses when compared to the feral horses studied.

Pharmacokinetics and bioequivalence testing of five commercial formulations of omeprazole in the horse.

Omeprazole is widely used in the treatment of equine gastric ulcer syndrome. To date, little is known about the relative pharmacokinetics of the different formulations making comparisons between products difficult. The objectives of the study were to investigate the relative pharmacokinetics of five commercially available formulations of omeprazole in the horse and to test for bioequivalence of four of the formulations using one of the formulations as a reference standard. Twelve mature Thoroughbred horses were fasted for 16 h then administered 2 g of each formulation in a cross-over design. Serial blood samples were collected and plasma omeprazole concentration was determined by ultra high-performance liquid chromatography-mass spectrometry (UHPLC-MS). No significant differences were present between three of the formulations and the reference formulation, while the fourth formulation had a lower Cmax and longer Tmax than the reference formulation. Bioequivalence against the reference formulation could not be demonstrated for any of the formulations tested. The findings of the study suggested that the method of protection utilised by different formulations of omeprazole (enteric-coated granules vs. buffering) does not significantly alter the pharmacokinetics of the drug. Further work to establish bioequivalence is needed before direct comparisons can be drawn between different formulations.