Equine Glandular Gastric Disease Research Articles

80 Preliminary investigation of gastro-well on Equine Glandular Gastric Disease prevalence in competition horses

The European College of Equine Internal Medicine (ECEIM) has expanded the nomenclature surrounding EGUS to 2 distinct diseases with differences in pathophysiology, risk factors, treatment response, and grading systems: Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGD). Although the mechanism, risk factors and pathophysiology of ESGD is well characterized, the mechanism of EGGD still requires elucidation, which may explain the ECEIM recommendation to move away from using fasting models to investigate therapeutic efficacy of nutraceuticals and drugs in naturally occurring disease states. Further most of the previous work in nutraceuticals either does not delineate location of ulcer or focuses on squamous tissue. Recently, the nutraceutical, Gastro-Well (GW; Probiotech International Inc.), was able to reduce naturally occurring EGUS in competition horses after 4wk but did not specify the ulcer location. The objective of this preliminary study was to examine GW, a proprietary blend of minerals, prebiotics, yeast, and psyllium, on performance horses with EGGD. Six mature (7–16y) competition horses with a history of EGGD were enrolled in the study. Two weeks before the initialgastroscopes, all nutraceuticals and medications for EGGD ceased. Gastroscopes were performed on d 0 and after 30d of GW supplementation at 360g/d. Because the ECEIM recommends a descriptive system to assess glandular ulcers without a numeric designation as in the squamous scoring system, images of the glandular ulcers from the gastroscopic examinations were sent in randomized pairs to a veterinarian blinded to order, to determine which image looked healthier based on the ECEIM description of EGGD or if there was no difference. Positive response to GW was determined when the post-image was deemed healthier. The binary data was analyzed by Chi-squared to determine statistical significance (P < 0.05) and trends (P < 0.10). There was a trend (P = 0.08) for positive response to GW. The result demonstrates that GW may have the potential to support glandular gastric health in at-risk competition horses with EGGD. Further research is warranted to replicate these findings with a larger sample size.

Five- versus seven-day dosing intervals of extended-release injectable omeprazole in the treatment of equine squamous and glandular gastric disease.

An extended-release injectable omeprazole formulation (ERIO) has become a popular treatment for equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD) where it is available; however, published data are limited and optimal treatment regimens have not been determined. To compare effects of treatment on ESGD and EGGD when an ERIO formulation is administered at either 5- or 7-day intervals. Retrospective clinical study. Case records and gastroscopy images of horses with ESGD or EGGD treated with ERIO were reviewed. Images were anonymised and graded by one researcher masked to treatment group. Treatment responses were compared between the two treatment schedules using univariable ordered logistic regression. Forty-three horses were treated with ERIO at 5-day intervals and 39 horses at 7-day intervals. Signalment and presenting signs did not differ between groups. The proportions of horses with EGGD healing (to grade 0 or 1) in association with ERIO used at 5-day intervals (93%) were higher than associated with treatment at 7-day intervals (69%; odds ratio [OR]: 2.41, 95% CI: 1.23-4.74, p = 0.01). For ESGD, there was no significant difference in the proportion of horses healing in association with treatment at 5-day intervals (97%) compared with 7-day intervals (82%; OR: 2.75, 95% CI: 0.91-8.31, p = 0.07). Four of 328 injections were associated with an injection-site reaction (1%). Retrospective study design, lack of randomisation and limited case numbers. The use of ERIO at 5-day intervals might be more appropriate than the 7-day interval that is used currently.

Changes in Calprotectin (S100A8-A9) and Aldolase in the Saliva of Horses with Equine Gastric Ulcer Syndrome.

Equine gastric ulcer syndrome (EGUS) is a highly prevalent disease that affects horses worldwide. Within EGUS, two different forms have been described: equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD). The associated clinical signs cause detrimental activity performance, reducing the quality of life of animals. Saliva can contain biomarkers for EGUS that could be potentially used as a complementary tool for diagnosis. The objective of this work was to evaluate the measurements of calprotectin (CALP) and aldolase in the saliva of horses as potential biomarkers of EGUS. For this purpose, automated assays for the quantification of these two proteins were analytically validated and applied for detecting EGUS in a total of 131 horses divided into 5 groups: healthy horses, ESGD, EGGD, combined ESGD and EGGD, and horses with other intestinal pathologies. The assays showed good precision and accuracy in analytical validation, and they were able to discriminate between horses with EGUS and healthy horses, especially in the case of CALP, although they did not show significant differences between horses with EGUS and horses with other diseases. In conclusion, salivary CALP and aldolase can be determined in the saliva of horses and further studies are warranted to elucidate the potential of these analytes as biomarkers in EGUS.

Equine Gastric Ulcer Syndrome: An Update on Current Knowledge.

Equine Gastric Ulcer Syndrome (EGUS) is a term that has been used since 1999, initially being used to describe all gastric mucosal disease in horses. Since this time, the identification of two distinct main disease entities of the equine gastric mucosa have been described under the umbrella of EGUS; these are Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGD). In 2015 the European College of Equine Internal Medicine (ECEIM) released a consensus statement defining these disease entities. This document highlighted the lack of evidence surrounding EGGD compared to ESGD, and identified knowledge gaps for further research to be directed. Subsequently, many studies on EGGD have been published, especially on pathophysiology, diagnosis, and treatment. This article updates current knowledge on both ESGD and EGGD as understanding has evolved since the last large-scale review.

A Comparison of the Efficacy of Two Omeprazole Formulations in the Treatment of Equine Gastric Ulcer Syndrome in Racehorses: A Blinded, Randomized Clinical Trial

Equine gastric ulcer syndrome (EGUS) is the most common disease of the stomach in horses and treatment is based on the oral administration of omeprazole for at least 28 days. Aim of this study was to compare the efficacy of two formulations of oral omeprazole—powder paste and gastro-enteric resistant granules—in the treatment of naturally occurring gastric ulcers in racehorses. Thirty-two adult racehorses, aged between 2 and 10 years old, with clinical signs of EGUS were included in this blinded, randomized clinical trial. Two gastroscopies were performed to evaluate gastric lesions in the squamous or glandular mucosa before and after 28 days of treatment. After the first gastroscopy, 2/32 horses were excluded because affected by equine squamous gastric disease (ESGD) 1/4. The remaining horses were divided into 4 groups, and were treated with 2 formulations of omeprazole (gastroenteric resistant granules, group 1, or powder paste, group 3) or with 2 placebo formulations (granules, group 2, or paste, group 4). Treatments were performed in the placebo horses affected by ESGD or equine glandular gastric disease after the T28 gastroscopy control. No differences were found between groups at T0. Differences were found between T0 vs. T28 for granular (P = .002) and powder paste (P = .01) formulations. No differences were detected between the two groups receiving omeprazole formulations at T28 (0.34) and between T0 vs. T28 for either of the groups receiving placebo treatments. For all the variables, the size of the effect was greater than 0.5, proving that the treatments had a considerable effect. Gastro-enteric resistant granules and powder paste omeprazole showed similar efficacy in the treatment of ESGD. The glandular mucosa responded poorly to treatment with omeprazole.

Low therapeutic success rates with both high-dose therapy with omeprazole granules (Equizol©) and combination therapy with omeprazole paste (Gastrogard®) and sucralfate (Sucrabest®) in horses with Equine Glandular Gastric Disease (EGGD)

Low therapeutic success rates with both high-dose therapy with omeprazole granules (Equizol©) and combination therapy with omeprazole paste (Gastrogard®) and sucralfate (Sucrabest®) in horses with Equine Glandular Gastric Disease (EGGD)

Does lesion type or severity predict outcome of therapy for horses with equine glandular gastric disease? - A retrospective study.

Equine glandular gastric disease (EGGD) is a common condition of the horse. Misoprostol is reported to be superior to oral omeprazole and sucralfate for treatment. Long-acting intramuscular injectable omeprazole (LAIOMEP) is a novel treatment shown to be effective in a small population. This study aimed to determine LAIOMEP efficacy compared to misoprostol and oral omeprazole and identify characteristics that predict treatment outcome. All horses that underwent gastroscopy between 2012 and 2019 were reviewed. Lesions were characterised by 4 blinded observers, all of whom are diplomates in equine internal medicine, using established descriptors from the ECEIM consensus statement and subjective severity. Treatment outcome was ranked as worsened, improved or healed. Consensus lesion type, lesion severity and treatment choice were compared to outcome and data screened using univariate analysis (chi-squared) to determine whether each predicted outcome. Lesion types where univariate analysis predicted a trend (p<0.2) were included in a multiple-regression analysis to identify predictors of outcome irrespective of treatment. Only severity significantly predicted final outcome (p = 0.025) with severe lesions being more likely to improve. Treatment choice did not significantly predict outcome. Overall healing rate was 29% (24 horses), and 43% (44 horses) improved. Treatment healing rates were 23% (10), 12% (7) and 27% (7) for LAIOMEP, misoprostol and oral omeprazole, respectively, with improvement in 69% (14), 76% (21) and 61% (9). 64% of the latter group received sucralfate. Worsening occurred in 7% (6). Treatment length varied with a median of 4 weeks (range 4-20 weeks). This study showed poorer therapy outcome compared to previous studies. The only initial lesion descriptor to predict outcome was severity and treatment choice did not affect outcome.

Effect of moving from being extensively managed out in pasture into training on the incidence of equine gastric ulcer syndrome in Icelandic horses.

To investigate equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD) in Icelandic horses moving from pasture into training. 81 horses (median age, 3 years; interquartile range, 1 year) from 10 farms representing 4 different Icelandic regions. Initial gastroscopy was undertaken within 2 weeks of moving from pasture into a training establishment. A total of 71 horses underwent endoscopic examination again 8 weeks later. Various management and behavioral factors were assessed through face-to-face questionnaires with the owners or trainers. Multivariable logistic regression was used to determine factors contributing to any change in ESGD and EGGD severity score during the 8-week training period. Incidence of EGGD and ESGD in this feral population was similar to that found in domesticated horses. ESGD incidence (severity score, ≥ 2; score range, 0 to 4) reduced from an initial 71.6% (58/81) to 25.4% (18/71). On multivariable analysis, sex (ie, being a stallion or a female vs gelding) increased the likelihood of ulcer grade reduction. Being fed preserved forage 3 or more times a day also improved the likelihood of ESGD reduction (odds ratio, 17.95; 95% CI, 1.67 to 193.40; P = .017). Overall, the farm explained 35% of the variance, confirming the importance of management factors. Incidence of EGGD (severity score, ≥ 1; score range, 0 to 2) reduced from 47% (38/81) to 40.8% (29/71) during the same period. No measured variables were associated significantly with EGGD incidence or reduction. Pasture provision (without supplementary feed or forage) does not result automatically in a low incidence of gastric ulcers. Regular provision of preserved forage is a key factor in reducing ESGD incidence.

Dietary and management factors influence the equine gastric microbiome.

The purpose of this study was to characterize the relationship of diet and management factors with the glandular gastric mucosal microbiome. We hypothesize that the gastric mucosal microbial community is influenced by diet and management factors. Our specific objective is to characterize the gastric mucosal microbiome in relation to these factors. 57 client-owned horses in the southern Louisiana region with and without equine glandular gastric disease. Diet and management data were collected via a questionnaire. Gastroscopy was used for evaluation of equine gastric ulcer syndrome and collection of glandular mucosal pinch biopsies. 16S rRNA amplicon sequencing was used for microbiome analysis. Similarity and diversity indices and sequence read counts of individual taxa were compared between diet and management factors. Differences were detected in association with offering hay, type of hay, sweet feed, turnout, and stalling. Offering hay and stalling showed differences in similarity indices, whereas hay type, sweet feed, and turnout showed differences in similarity and diversity indices. Offering hay, hay type, and sweet feed were also associated with differences in individual sequence read counts. This study provides preliminary characterization of the complex relationship between the glandular gastric microbiome and diet/management factors. The ideal microbiome to promote a healthy glandular gastric environment remains unknown.

Equine Gastric Ulcer Syndrome affects fitness parameters in poorly performing Standardbred racehorses.

Equine Gastric Ulcer Syndrome (EGUS) is a highly prevalent disorder in horses, which can be classified, based on the localization of the lesions, as Equine Squamous Gastric Disease (ESGD) or Equine Glandular Gastric Disease (EGGD). Although EGUS is recognized as a common cause of poor performance in racehorses, objective investigations about its relation with athletic capacity are lacking. Therefore, the present retrospective study aims to evaluate the associations between EGUS severity and some fitness parameters measured during an incremental treadmill test in Standardbred racehorses in training. With this aim, data from 87 Standard bred racehorses which underwent a complete diagnostic evaluation for poor performance was reviewed. During gastroscopic examination, a 0-4 score was assigned to ESGD, while EGGD was evaluated for absence/presence; a total EGUS score was obtained by adding 1 point to ESGD score in horses showing concomitant EGGD. Fitness parameters obtained during incremental treadmill test included speed at a heart rate of 200 bpm (V200), speed and heart rate at a blood lactate of 4 mmol/L (VLa4, HRLa4), peak lactate, lactate and heart rate at 30 minutes post-exercise, maximum speed, minimum pH and maximum hematocrit. The associations between fitness parameters and EGUS and ESGD scores were evaluated by Spearman correlation, while Mann-Whitney test was used to compare them between horses with or without EGGD. Statistical significance was set at p<0.05. EGUS grade was inversely correlated with V200 (p = 0.0025) and minimum pH (p = 0.0469); ESGD grade was inversely correlated with V200 (p = 0.0025) and VLa4 (p = 0.0363). Although a trend was observed, no significant differences in V200 were observed between horses with or without EGGD (p = 0.073); horses with EGGD reached a lower minimum pH (p = 0.0087). These results show a negative association between aerobic capacity and EGUS, in particular ESGD. Although different hypotheses have been proposed, including abdominal pain and decreased appetite due to lactate accumulation, the underlying mechanisms are still unknown, and it is not clear whether EGUS represents a cause or a consequence of an early lactate accumulation and post-exercise acidosis.

Prophylactic effects of Glycyrrhiza glabra root extract on phenylbutazone-induced Equine Glandular Gastric Disease (EGGD)

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), like phenylbutazone (PBZ), are prescribed to treat pain and inflammation in the equine. However, experimentally their use has been associated with the development of Equine Glandular Gastric Disease (EGGD). To evaluate the prophylactic effects of Glycyrrhiza glabra root extracts (GGRE) on EGGD induction following oral administration of PBZ, 12 donkeys were used. Animals were divided into three equal groups (A, B and C) in a randomized block design. A: placebo, B: PBZ (4.4 mg/kg PO q 12 h) and C: PBZ plus GGRE (17.6 mg/kg PO q 24h). Gastroscopy and blood sampling for CBC, biochemical tests and antioxidant status were performed days 0 and 7. All but 1 animal had no EGGD lesions on day 0, but on day 7, severe EGGD lesions were seen in group B animals (grade 1/4 (× 1), grade 2/4 (× 2), and grade 3/4 (× 1)). Only mild changes were seen in group C animals, the most severe lesions being grade 1/4 lesions in 2 animals. No change was observed in Group A. Hematology and serum antioxidant status did not change significantly in any group. In group B glucose decreased and ALT and ALP increased, while in group C only ALP increased. In conclusion, GGRE reduced the severity of EGGD caused by PBZ. Further, GGRE prevented PBZ induced hypoglycemia and might reduce the possible hepatic injury of PBZ.

Changes in Proteins in Saliva and Serum in Equine Gastric Ulcer Syndrome Using a Proteomic Approach.

Simple SummaryEquine gastric ulcer syndrome (EGUS) is a highly prevalent disease with a major clinical importance due to its negative effects on the welfare and performance of horses. EGUS can be distinguished into two different diseases depending on which anatomical region is affected: equine glandular gastric disease (EGGD), in which there is a lesion in the glandular stomach, and equine squamous gastric disease (ESGD), in which the alteration appears in the non-glandular stomach. EGUS has nonspecific clinical signs, and its underlying mechanism has not been completely elicited. Therefore, it would be of interest to clarify the pathophysiology and identify potential biomarkers of this syndrome. This study detected differences in the salivary and serum proteome between horses with EGUS and healthy horses, and also between horses with EGGD and ESGD. The most upregulated proteins in EGGD were related to the immune activation whereas, in horses with ESGD, the proteins with the most significant changes were associated with the squamous cell regulation and growth. Compared to serum, saliva had a higher number of proteins showing significant changes and also showed a different pattern of changes, indicating that the proteins in both fluids show a different response to the disease and can provide complementary information.Changes in the salivary proteome in 12 horses with the two diseases included in equine gastric ulcer syndrome (EGUS), equine glandular gastric disease (EGGD) (n = 6) and equine squamous gastric disease (ESGD) (n = 6), were evaluated using a high-resolution LC-MS/MS analysis of TMT-labelled peptides and compared to 10 healthy control horses. Serum was also analysed for comparative purposes. The comparison between the horses with EGGD and controls showed significant changes in 10 salivary proteins, whereas 36 salivary proteins were differently abundant between ESGD and control groups. The most upregulated proteins in the case of EGGD were related to immune activation whereas, in horses with ESGD, the most significantly changed proteins were associated with squamous cell regulation and growth. Compared to serum, saliva showed a higher number of proteins with significant changes and a different pattern of changes. The proteins identified in our study, in addition to providing new information about the pathophysiological mechanisms in these diseases, could have the potential to be novel biomarkers for the diagnosis or monitoring of EGGD and ESGD.

Nutritional management of equine gastric ulcers

Over the last 10 years there has been increasing awareness and subsequently recorded cases of equine gastric ulcer syndrome and with this comes an increased interest in appropriate nutrition and feed management. This review presents a systematic approach to assessing the ration of a horse at risk or diagnosed with equine gastric ulcer syndrome and demonstrates the ample evidence upon which to base nutritional recommendations for horses with equine squamous gastric disease, and to a lesser extent, equine glandular gastric disease, with an emphasis on forage. Careful selection and management of the forage ration should be the first step in designing a suitable ration, followed by selection of an appropriately low starch and sugar (less than 2g per kg body weight per day and 1g per kg body weight per meal) complementary feed. There is still more to learn about the role of supplements in the prevention and treatment of equine gastric ulcer syndrome, thus these should currently be viewed as an adjunct to an appropriate base diet and not as an isolated solution.

A study comparing the healthy and diseased equine glandular gastric microbiota sampled with sheathed transendoscopic cytology brushes

The role of the equine gastrointestinal microbiota in the pathogenesis of equine glandular gastric disease (EGGD) is poorly understood. To investigate whether the glandular gastric microbiota is altered in horses with EGGD. Prospective longitudinal study. Five Thoroughbred racehorses from one training center underwent gastroscopy as part of poor performance investigation. Samples were taken from EGGD lesions and adjacent normal mucosa using sheathed transendoscopic cytology brushes and frozen at -80°C. DNA was extracted for 16S rRNA sequencing, and sequences compared against a database to generate taxonomic classification of the microbiota. The same horses were sampled 6 months later. Normal glandular mucosal samples were characterized by a higher proportion of Proteobacteria (46.3%) than EGGD lesions (18.9%). Relative abundance of Firmicutes was lower in samples from normal mucosa (20.0%) than EGGD lesions (41.2%). Linear discriminant analysis effect size (LEfSe) confirmed a greater proportion of Firmicutes species was characteristic of samples collected from EGGD lesions due to a very high relative abundance of Sarcina (up to 92.4%) in two horses with EGGD. We were unable to comment on the stability of the glandular gastric microbiota over time. Small sample population. None of the horses examined had grossly normal gastric mucosa. The gastric microbiota appears altered in EGGD, although we are unable to demonstrate a causative effect. Sarcina was particularly increased in abundance in EGGD and may be a useful biomarker of disease. Sheathed cytology brushes were an effective method for sampling the gastric mucosa.

Assessment of agreement using the equine glandular gastric disease grading system in 84 cases

IntroductionEquine glandular gastric disease (EGGD) is a common condition causing signs of gastric pain although lesions are highly variable in their appearance. The only definitive method to diagnose EGGD ante‐mortem is gastroscopy. The current recommended method for describing these lesions is the European College of Equine Internal Medicine (ECEIM) guidelines; however, repeatability between users is variable. This study aimed to validate the reliability of lesion descriptions using ECEIM consensus guidelines, using four blinded equine internal medicine diplomates.MethodsNinety‐two horses with EGGD with pre‐ and post‐treatment gastroscopy images were identified using the electronic record at a UK equine hospital between 2012 and 2019. Eight horses were excluded due to non‐diagnostic images. Four blinded observers used the recommended grading system to describe images and outcomes. Intraclass correlation coefficients and Krippendorff's alpha were used to determine reliability and agreement, respectively.ResultsIntraclass correlation coefficient for severity was 0.782 (95% confidence interval [CI] 0.722–0.832), for distribution was 0.671 (95% CI 0.540–0.763), for the descriptor raised was 0.635 (95% CI 0.479–0.741), fibrinosuppurative was 0.745 (95% CI 0.651–0.812), haemorrhagic was 0.648 (95% CI 0.513–0.744), hyperaemic was 0.389 (95% CI 0.232–0.522) and for outcome was 0.677 (95% CI 0.559–0.770). Krippendorff's alpha for severity was 0.466 (95% CI 0.466–0.418), for distribution was 0.304 (95% CI 0.234–0.374), for the descriptor raised was 0.268 (95% CI 0.207–0.329), fibrinosuppurative was 0.406 (95% CI 0.347–0.463), haemorrhagic was 0.287 (95% CI 0.229–0.344), hyperaemic was 0.112 (95% CI 0.034–0.188) and for outcome was 0.315 (95% CI 0.218–0.408).There was moderate reliability determined between observers using intra‐class correlation coefficients and unacceptable agreement determined between observers using Krippendorff's alpha.DiscussionThese results suggest that the current grading system is not comparable between observers, indicating the need to review the grading system or define more robust criteria.

Evaluation of the treatment of equine glandular gastric disease with either long‐acting‐injectable or oral omeprazole

BackgroundEquine glandular gastric disease (EGGD) is common in domesticated horses and can be challenging to treat. Oral omeprazole (ORLO) is used widely but the clinical response is frequently poor.ObjectivesTo compare rates of EGGD healing and improvement between ORLO and a long‐acting injectable omeprazole preparation (LAIO).Study designRetrospective clinical study.MethodsThe case records and gastroscopy images of horses presenting to masked for peer review over a 12‐month period were reviewed, with images blindly assessed by one of the authors. Treatment responses to 4 mg/kg LAIO administered every 7 days for 2 and 4 weeks were compared with ORLO 4 mg/kg PO q24hrs for 4 weeks. Data were compared using a Mann‐Whitney U test with post‐hoc Dunn's test, Chi‐squared test and a Fisher's exact test.ResultsThirty‐three horses that received LAIO and 12 that received ORLO were identified. Nine horses in the LAIO had received other treatments previously. The groups were comparable in signalment and EGGD lesion severity. Long‐acting injectable omeprazole was found to be non‐inferior to ORLO. LAIO was associated with better healing rates than ORLO at 4 weeks (LAIO‐80%; ORLO‐42%; p = 0.02), and reduction in lesion severity at 2 and 4 weeks in the LAIO group but not in the ORLO group at 4 weeks. Eighteen percent of horses in the LAIO group and 50% in the ORLO group did not heal at 4 weeks. There was no association between rate of healing or improvement and resolution or improvement of clinical signs. Six localised and self‐limiting injection site reactions were identified in 4 horses treated with LAIO (6.7%).Main limitationsRetrospective design, small numbers and the use of other treatments prior to use of LAIO.ConclusionsLAIO was found to be non‐inferior to oral omeprazole for EGGD. Larger blinded randomised clinical trials are justified.

Esomeprazole in the treatment of equine glandular gastric disease

Background:Equine glandular gastric disease is a highly prevalent disease, for which there is no universally effective treatment. Given the widespread use of esomeprazole in the treatment of peptic ulcer disease in humans, its use in horses warrants further investigation.Objective:To assess rates of healing of equine glandular gastric disease using oral esomeprazole.Study design:Retrospective case series.Methods:Medical records and gastroscopy images of horses diagnosed with equine glandular gastric disease and treated with esomeprazole by Avon Ridge Equine Veterinary Services were reviewed.Results:Out of four horses treated with esomeprazole for 28 days, 75% (three) healed and 25% (one) did not improve. Out of three horses treated with esomeprazole for 14 days, 67% (two) healed and 33% (one) did not improve.Main limitations:The study was limited by its retrospective nature and small sample size.Conclusions:Esomeprazole may be a valid first-line treatment option for equine glandular gastric disease. Larger and more robust studies of esomeprazole are warranted.

Association between owner‐perceived clinical signs and the presence of equine glandular gastric disease on endoscopy

Association between owner‐perceived clinical signs and the presence of equine glandular gastric disease on endoscopy

Assessment of agreement using the equine glandular gastric disease grading system in 92 cases

Assessment of agreement using the equine glandular gastric disease grading system in 92 cases

Clinical efficacy, safety and pharmacokinetics of a novel long‐acting intramuscular omeprazole in performance horses with gastric ulcers

SummaryOral omeprazole is used in the management of equine gastric ulcer syndrome (EGUS). However, its use may have limitations with regard to individual variation in absorption and the impact of dietary management on bioavailability. The objective of this study was to determine whether a novel compounded long‐acting injectable omeprazole (LAO‐USA) formulation would provide consistent serum omeprazole concentrations and to determine whether it was clinically safe and efficacious in the reduction of EGUS. Twenty‐three horses with EGUS described as having evidence of equine squamous gastric disease (ESGD) and/or equine glandular gastric disease (EGGD) received a 5 mg/kg bwt intramuscular injection of LAO‐USA once every 7 days for four doses. Gastroscopy was performed prior to the study and at Days 14 and 28. Pharmacokinetic analysis was performed to determine omeprazole concentrations over 7 days. Safety was measured by monitoring injection site reactions daily and bloodwork screening prior to and following the study. Of the horses with ESGD, 78% had improvement by Day 14 (p = 0.0035), with no further improvement from Day 14 to 28 (p &gt; 0.99). ESGD grades from Day 0 to 28 decreased significantly (95% CI −1.92 to −0.91 grades) (p = 0.0002). Out of the horses (6/23) that had glandular lesions, 5/6 healed over time; however, this was not a significant change (p = 0.75). Injection reactions included oedema, heat and pain at the injection site. Considering the total number of injections across the whole study, 23% of horses experienced an injection site reaction. The number of injection site reactions increased following each dose (8%, 13%, 22% and 48%, respectively). The formulation did not appear to have adverse systemic effects. Serum omeprazole meanCmaxwas 46.2 ng/ml (±17.4 ng/ml), and these concentrations maintained at approximately 9.6 ng/ml (±4.6 ng/ml) for 7 days following dosing. This formulation is compounded and has not completed FDA investigation, which may increase formulation variability as it is produced or stored. The lack of control groups and potential bias in lesion grading are additional recognised limitations. The results of this study provide preliminary safety and efficacy data with regard to a novel LAO‐USA formulation. Future study is warranted to describe safety and efficacy for both ESGD and EGGD and would support further FDA investigation.