Associations between age or sex and prevalence of gastric ulceration in Standardbred racehorses in training

Prevalence and Risk Factors for the Presence of Gastric Ulcers in Pleasure and Breeding Horses in Italy

Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGD) are two terms used to indicate the presence of lesions of the squamous and glandular mucosa of the stomach. Prevalences, pathophysiology, and risk factors are different, and the latter have been investigated in different populations. The aim of this study was to investigate the prevalence and risk factors of ESGD and EGGD in a cohort of pleasure, breeding, and retired horses in Italy. To the authors' knowledge, this is the first study to investigate such a diverse population of animals and the first one that includes a large number of animals in Italy. Gastroscopies were performed in 316 animals, with and without clinical signs of gastric ulcers, and a questionnaire about signalment, management, activity, and health was given to the owners or caretakers. Prevalence of ESGD was similar to the current literature reports in comparable populations, and the disease was associated with signalment, time with the current owner or caretaker, management (time and type of paddock, hay, and supplementary feed administered), and activity performed. In this population, EGGD was present in a lower percentage of animals and, of the parameters evaluated, was associated only with the signalment, while management does not seem to influence the development of lesions in the glandular mucosa in this population.

Is There a Difference in the Prevalence of Gastric Ulcers between Stallions Used for Breeding and Those Not Used for Breeding?

Equine gastric ulcer syndrome (EGUS) is a worldwide disease, and includes two different syndromes, Equine Squamous Gastric Disease (ESGD), affecting the squamous mucosa, and Equine Glandular Gastric Disease (EGGD), affecting the glandular mucosa. These two diseases are present in different categories (different activities, ages, etc.) and breeds of horses. The effect of sex on gastric health is not clear: some studies found a higher prevalence of ESGD in geldings and stallions, while others found no influence of sex on the squamous mucosa. The few studies conducted on glandular diseases failed to identify sex as a risk factor. The only study on breeding horses, focused on Thoroughbred mares at pasture, found that 70% of them were affected by gastric ulcerations especially in the squamous mucosa. The aim of this study was to determine the prevalence of EGUS, ESGD, and EGGD in intact males while also investigating the potential influences of breeding and exercise activity on the occurrence and severity of the diseases. A total of 101 intact males were admitted for gastroscopic examination. Comprehensive data regarding their breeding and sports history, management, and presence of clinical signs were recorded. A statistical analysis was performed. Within this equine population, no discernible relationship was found between breeding activity and occurrence and severity of ESGD or EGGD. Exercise and a combination of exercise and breeding activities were found to be associated with the occurrence of EGGD. The presence of clinical signs was correlated only with the grade of ESGD in this cohort of horses.

Gastroscopic characterisation and prevalence of gastric ulcer syndrome in working mules in Colombia

BACKGROUND

The existing literature does not contain information about the prevalence of gastric ulcers in mules, and on the potential associations between the presence of ulcers and work load, work type, diet, sex, age and body condition score (BCS).

OBJECTIVE

To estimate the prevalence and factors associated with mule gastric ulcer syndrome (MGUS) and evaluate its distribution in both mule squamous gastric disease (MSGD) and mule glandular gastric disease (MGGD) mucosa in a population of mules in Colombia.

STUDY DESIGN

Observational, cross-sectional.

METHODS

A total of 97 clinically healthy mules of different ages and locations in the province of Antioquia (Colombia) were included in this study. The mules were involved in agricultural activities (i.e., riding, pack and ranch mules) at the time of the study. The animals underwent gastroscopic evaluation, and ulcer scores from 0 to 4 were assigned based on severity, with scores ≥2 indicating clinical relevance. The presence or absence of ulcer in the squamous and/or glandular region of the stomach was recorded. Data related to work type, work load and diet, as well as sex, age and BCS were recorded for each mule. Pearson's chi-square test was used to determine the association between the outcomes and explanatory variables of the study (p ≤ 0.05). The results of the risk estimations were presented as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

The frequency of MGUS in the study population was 42%. Most of the lesions were located in the squamous region of the stomach (27%), mainly in the margo plicatus, and 20% were located in the glandular region, mainly in the fundus and pyloric antrum. Six animals showed lesions in both squamous and glandular regions. Work load was the only variable associated with the presence of MGUS (OR: 1.98; 95% CI: 0.49-0.96) and MSGD (OR: 1.78; 95% CI: 0.36-0.67). Nevertheless, the findings did not provide any significant risk assessment result, nor did they reveal any significant interactions among the other variables.

MAIN LIMITATIONS

This study used convenience sampling from a limited geographic region, and multivariate analysis was not performed, one of the exclusion criteria was the use of nonsteroidal anti-inflammatory drugs, which means that the effect of these drugs can no longer be evaluated.

CONCLUSIONS

MGUS occurs in mules subjected to agricultural work, the risk factors associated with EGUS do not appear to be significant in mules and other equids subjected to the same conditions, in this region. Further research is needed to define the differential dynamics of MGUS in comparison with the findings in horses.

Effect of a blend of magnesium oxide on Equine Squamous Gastric Disease in young trotter horses under training

BACKGROUND

Equine squamous gastric disease (ESGD), as part of the equine gastric ulcer syndrome (EGUS), are common in racing horses. The use of buffering feed supplements to treat and/or prevent gastric ulcers is an option to control this condition.

OBJECTIVE

The purpose of this study was to evaluate the effect of a 30-day supplementation with a blend of magnesium oxide (MgO) on ESGD scores in trotters under training.

METHODS

Forty-two young trotters were submitted to a gastroscopic evaluation to assess their ESGD score and were randomly assigned in a group supplemented with MgO or in a control group. After 30 days, a second evaluation by gastroscopy was performed. The effect of the MgO supplementation was assessed by comparing the evolution of the ESGD score in supplemented and control groups between day 0 and day 30.

RESULTS

The results confirm the high prevalence of EGUS in young Trotters. The supplementation significantly decreased the ESGD scoring in the supplemented group whereas the control group remain unchanged.

CONCLUSION

The oral MgO supplementation was efficient to control ESGD in the population studied.

Medical causes of poor performance and their associations with fitness in Standardbred racehorses

BACKGROUND

Poor performance is a multifactorial syndrome of racehorses, commonly associated with subclinical disorders, which can be diagnosed by exercise testing.

OBJECTIVES

Describe the prevalence of medical causes of poor performance in Standardbreds unassociated with lameness, and evaluate their relationships with fitness variables measured by exercise treadmill test.

ANIMALS

Hospital population of 259 nonlame Standardbred trotters referred for poor performance.

METHODS

The horses' medical records were retrospectively reviewed. Horses underwent a diagnostic protocol including resting examination, plasma lactate concentration, treadmill test with continuous ECG and assessment of fitness variables, creatine kinase activity, treadmill endoscopy, postexercise tracheobronchoscopy, bronchoalveolar lavage (BAL), and gastroscopy. The prevalence of different disorders was evaluated, including cardiac arrhythmias, exertional myopathies, dynamic upper airway obstructions (DUAOs), exercise-induced pulmonary hemorrhage (EIPH), moderate equine asthma (MEA), and gastric ulcers (EGUS). The associations of these disorders with fitness variables were investigated individually and using multivariable models.

RESULTS

Moderate equine asthma and EGUS were the most common disorders, followed by EIPH, DUAOs, cardiac arrhythmias, and exertional myopathies. Hemosiderin score was positively correlated with BAL neutrophils, eosinophils, and mast cells; increased creatine kinase activity was associated with BAL neutrophilia, DUAOs, premature complexes, and squamous gastric disease. Treadmill velocity at a plasma lactate concentration of 4 mmol/L and at heart rate of 200 beats per minute was negatively affected by BAL neutrophilia, multiple DUAOs, exertional myopathies, and squamous gastric disease.

CONCLUSIONS

The multifactorial nature of poor performance was confirmed, with MEA, DUAOs, myopathies and EGUS representing the main diseases involved in fitness impairment.

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

Introduction

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.

Methods

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.

Results

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).

Discussion

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.

Prevalence of Gastric Ulceration in Horses with Enterolithiasis Compared with Horses with Simple Large Intestinal Obstruction

Enterolithiasis is a well-documented cause of colic in horses, especially in some geographic areas such as California and Florida. This retrospective case-control study aims at comparing the prevalence of gastric ulcers in horses affected by enterolithiasis to that in horses affected by other types of large intestinal obstruction. Two hundred and ninety-six horses were included in the study sample. Horses that had surgery for the removal of one or more enteroliths were included in the study as cases. Patients that had surgery for large intestinal simple obstructions other than enterolithiasis (large colon displacement, non-strangulating large colon torsion, and large and small colon impactions) were selected to match case horses for age, sex, and breed and included as controls. A total of 101/148 horses with enteroliths (68%) had gastric ulcers diagnosed during hospitalization, compared with 46/148 of matched controls (31%). There was a significant association between enterolithiasis and gastric ulceration (odds ratio 4.76, p < 0.0001), and a greater prevalence in Thoroughbreds as compared with other breeds (odds ratio 22.6, p < 0.0001). We concluded that enterolithiasis is significantly associated with gastric ulceration (p < 0.0001). The association is stronger in Thoroughbreds.

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

OBJECTIVE

To investigate equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD) in Icelandic horses moving from pasture into training.

ANIMALS

81 horses (median age, 3 years; interquartile range, 1 year) from 10 farms representing 4 different Icelandic regions.

PROCEDURES

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.

RESULTS

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.

CLINICAL RELEVANCE

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.

Equine Squamous Gastric Disease: Prevalence, Impact and Management

This narrative review explores the etiopathogenesis, clinical signs, diagnosis and treatment of ESGD (equine squamous gastric disease) and discusses the impact of this commonly encountered condition on the equine industry. ESGD refers specifically to peptic injury of the squamous mucosa of the stomach. Prevalence is highest in performance horses, but the disease has been documented across many breeds and ages, including in feral horses and foals. The pathogenesis of ESGD is well understood. Intensive management and exercise are important factors that contribute to a disruption of the normal stratification of gastric pH. This results in exposure of the vulnerable squamous mucosa to acid, leading to ulceration. Clinical signs are variable and there is little evidence to support a direct association between reported signs and the presence or absence of lesions seen on gastroscopy. Management is aimed at acid suppression and mitigation of known risk factors.

Effect of omeprazole and sucralfate on gastrointestinal injury in a fasting/NSAID model

BACKGROUND

Equine gastric ulcer syndrome (EGUS) is a common and significant cause of morbidity in horses, with a range of clinical signs, including inappetence, colic and poor performance. Hospitalised horses are exposed to factors that may induce EGUS, including fasting and nonsteroidal anti-inflammatory drug (NSAID) administration, and may be at risk for development of squamous (ESGD) and glandular gastric disease (EGGD). Prophylactic anti-ulcer medication is often prescribed for these patients, but drug selection is complicated by different aetiology and response to treatment of ESGD and EGGD.

OBJECTIVES

To establish the efficacy of sucralfate or omeprazole used prophylactically in horses exposed to a combined feed-fast and NSAID administration EGUS induction protocol. We hypothesised that these drugs would be equally effective for prevention of gastric lesions in the experimental cohort.

STUDY DESIGN

Randomised crossover experimental design.

METHODS

Horses (n = 14) received either omeprazole (1 mg/kg PO q24h) or sucralfate (20 mg/kg PO q8h) while undergoing the feed-fast/NSAID protocol, allowed an 8-week washout period, and then administered the alternate treatment. Serial gastroscopy, ultrasound and haematology documented treatment effects.

RESULTS

ESGD and EGGD score increased over time under both treatments. There was a significant effect of treatment on EGGD scores (P < .001), with post-treatment EGGD scores higher for horses receiving sucralfate (median 3; IQR 2.25,3) than omeprazole (1; 1,1). The effect of treatment on ESGD scores just achieved significance (P = .05), with post-treatment ESGD scores higher for sucralfate (4; 3,4) than omeprazole (2; 2,3).

MAIN LIMITATIONS

This study was performed in healthy horses, and response to treatment may differ in horses with clinical illness. Additional investigation in a larger population may be required to detect significant differences in other clinical parameters.

CONCLUSIONS

Omeprazole was superior to sucralfate for mitigating gastric lesion severity in healthy horses exposed to a feed-fast/NSAID model.

Effects of a nutraceutical supplement in the management of mild equine squamous gastric disease in endurance horses

INTRODUCTION

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.

MATERIAL AND 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 treatment, gastroscopy was repeated. Scores were assigned according to the Equine Gastric Ulcer Council scoring system. All horses were weighed at the beginning and at the end of the study. ESGD grades and weight before and after treatment were compared.

RESULTS

At enrolment, median ESGD score in the treatment group was 2, while in the control group it was 1. After the treatment period, a significant decrease in ESGD grade was observed in the treatment group (median 1, p = 0.0078), while there was no change in the control group (median 2). No significant weight change was observed in either group.

CONCLUSION

Trophogast pellet was effective at promoting healing of mild ESGD in endurance horses.

Detecting Welfare in a Non-Verbal Species: Social/Cultural Biases and Difficulties in Horse Welfare Assessment

Simple Summary

There is a paradox about the welfare of horses in the domestic situation: on the one hand, horses are beloved partners for most owners, but on the other hand, scientific studies are converging to show that there is a high prevalence of welfare problems. There seems to be a mismatch between theoretical knowledge and field applications. In this review, we aim at disentangling the possible factors explaining such a paradox. Among them, we consider the impact of anthropomorphic and cultural biases, popular beliefs, but also overexposure to horses with compromised welfare state, which can change owners’ representation of what is a “normal” horse, on the undervaluation of horse welfare state. We suggest that, rather than simply having knowledge on what should be done, identifying the horse welfare state using validated animal-based indicators is essential to identify and promote best practices.

Abstract

Horses were domesticated for more than 5000 years and have been one of the most emblematic species living alongside humans. This long-shared history would suggest that horses are well known and well understood, but scientific data raise many concerns about the welfare state of most domestic horses suggesting that many aspects have been largely misunderstood. In the present review, we will examine some of the possible human factors that may explain the huge prevalence of welfare problems, despite horses being of special importance to humans. First of all, as horses are non-verbal, current management practices rely upon what one thinks is good for them, which opens the way to subjective interpretations and projections, based on one’s own subjective experience but probably still more on cultural/social norms and influences, traditions and beliefs. The lack of recognition, identification, or even the misinterpretation of signals are other potential reasons for welfare issues. Lastly, the over-exposure to animals with expressions of compromised welfare may lead to lower sensitivity of owners/professionals. That is why we lastly suggest that instead of simply providing information on what to do, we should promote validated visible indicators that leave less room for personal interpretation.

Pharmacokinetic and pharmacodynamic effects of 2 registered omeprazole preparations and varying dose rates in horses

Background

Omeprazole preparations vary in bioavailability in horses.

Hypothesis/Objectives

To characterize the pharmacokinetics and pharmacodynamics of an existing enteric‐coated oral omeprazole paste (REF) and a novel, in‐feed, enteric‐coated dry granule preparation (NOV).

Animals

Twelve Standardbred/Thoroughbred mares free from clinical disease.

Methods

A prospective, blinded randomized interventional study was trial, conducted in 3 parts: (a) bioavailability study, (b) dose titration study, and (c) comparative clinical pharmacodynamic study, each using a blocked crossover design.

Results

Consistent with the larger dose administered, Cmax (median, 1032 ng/mL; range, 576‐1766) and AUC0‐24 (median, 63.9 μg/mL*min; range, 42.4‐152.4) were greater after single oral administration of NOV than REF (282.7 ng/mL; range, 94.8‐390.2, and 319 23.8 μg/mL*min; range, 8.2‐42.3, respectively; both P = .004). No differences were observed between products for absolute oral bioavailability (NOV 55% range, 15‐88; REF 17% range, 10‐77; P = .25). Treatment with both preparations was associated with reduced gastric squamous ulcer scores and increased pH of gastric fluid. Bioequivalence was demonstrated for pharmacodynamic measures with the exception of % time pH <4, despite differences in dose rate and subsequent plasma omeprazole concentrations.

Conclusions and Clinical Importance

The findings of this study indicate that the NOV product would be a suitable alternative to the reference product, and confirm that plasma concentrations of omeprazole and omeprazole dose do not predict drug pharmacodynamics in horses.

The Effect of a Seaweed-Derived Calcium Supplement on Gastric Juice pH in the Horse

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 (Purina Omolene 100) and 1.5% BW grass hay/day. On testing days 0, 7, and 14, the horses received one of three pelleted dietary treatments (CON, MIN1 ×, MIN2 ×) in a randomized, crossover design. CON contained no added Calmin, MIN1 × provided Calmin at a 1 × concentration, and MIN2 × provided a 2 × dose. All horses underwent gastroscopy (Karl Storz, El Segundo, CA) prior to feeding the treatments, and at 2 and 4 hours postfeeding. Gastric juice was aspirated and pH measured using a benchtop pH meter (ThermoOrion pH Meter Model 410A). Overall, there was a significant time effect (P < .0001) with an increase in gastric juice pH from time 0 (2.31 ± 0.58) to 2 hours (5.52 ± 0.48) and 4 hours (3.59 ± 0.48). Gastric juice pH at 2 hours was higher (P = .0122) in MIN1 × (5.92 ± 0.58) and MIN2 × (5.92 ± 0.57) than CON (5.08 ± 0.58). These results demonstrate that adding Calmin to a meal increases buffering capacity at 2 hours postfeeding.

Prophylactic therapy with omeprazole for prevention of equine gastric ulcer syndrome (EGUS) in horses in active training: A meta-analysis

BACKGROUND

Guidelines regarding the impact and value of prophylaxis or maintenance therapy in equine gastric ulcer syndrome (EGUS) are not well-established or defined. The merits and the magnitude of effects of prophylaxis for spontaneous or recurrent squamous gastric ulceration in horses in training are uncertain.

OBJECTIVES

To pool data from randomised controlled trials (RCTs) to eliminate reporting bias and evaluate the efficacy of prophylactic omeprazole in the prevention of EGUS in training horses, and secondarily to compare prophylactic dosages of omeprazole.

STUDY DESIGN

Meta-analysis.

METHODS

This meta-analysis was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic literature search identified RCTs comparing omeprazole prophylaxis with sham in prevention of EGUS. Data were analysed using the Mantel-Haenszel test method to calculate risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CIs). Primary outcome was efficacy of prophylaxis. Secondary outcome was endoscopic severity of ulceration. The influence of study characteristics on the outcomes was examined by subgroup analyses.

RESULTS

In preventing gastric ulcer occurrence, omeprazole prophylaxis was superior to sham in training horses (7 trials, 566 horses, RR 0.28, 95% CI 0.18-0.43; 23.4% in omeprazole prophylaxis vs. 77.2% in sham; high quality evidence). Prevalence of ulceration was 75.3 and 87.2% in the sham arms of the 1 mg/kg and 2 mg/kg omeprazole groups, respectively. Severity scores were significantly lower for omeprazole vs. sham (mean difference [MD] -1.05; 95% CI -1.35 to -0.69). Subgroup analyses comparing prophylactic omeprazole dosages resulted in a mean difference of -0.94 and -1.60 for the 1 and 2 mg/kg groups, respectively.

MAIN LIMITATIONS

Studies showed heterogeneity with regard to prophylactic dose.

CONCLUSIONS

Omeprazole prophylaxis in active training horses significantly reduces gastric ulceration compared with no prophylaxis (sham) with the absolute effect of 566 fewer ulcers per 1000 horses treated.

Therapeutics for Equine Gastric Ulcer Syndrome

Equine gastric ulcer syndrome (EGUS) is an umbrella term used to describe ulcers in the nonglandular squamous and glandular mucosa, terminal esophagus, and proximal duodenum. Gastric ulcers in the squamous and glandular regions occur more often than esophageal or duodenal ulcers and likely have a different pathogenesis. At present, omeprazole is accepted globally as the best pharmacologic therapy for both regions of the stomach; however, the addition of coating agents and synthetic prostaglandins could add to its effectiveness in treatment of EGUS. Dietary and environmental management are necessary for prevention of recurrence.

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

Background

Equine 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.

Results

One 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.

Conclusions

Blood 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.

Electronic supplementary material

The online version of this article (doi:10.1186/s13028-017-0284-1) contains supplementary material, which is available to authorized users.

Effect of pectin, lecithin, and antacid feed supplements (Egusin®) on gastric ulcer scores, gastric fluid pH and blood gas values in horses

Background

The objectives of this study were to evaluate the effects of two commercial feed supplements, Egusin 250^® [E-250] and Egusin SLH^® [E-SLH], on gastric ulcer scores, gastric fluid pH, and blood gas values in stall-confined horses undergoing feed-deprivation.

Methods

Nine Thoroughbred horses were used in a three-period crossover study. For the three treatment groups, sweet feed was mixed with E-250, E-SLH, or nothing (control group) and fed twice daily. Horses were treated for 21 days, then an additional 7 days while on an alternating feed-deprivation model to induce or worsen ulcers (period one). In periods two and three, horses (n=6) were treated for an additional 7 days after feed-deprivation. Gastroscopies were performed on day -1 (n=9), day 21 (n=9), day 28 (n=9) and day 35 (n=6). Gastric juice pH was measured and gastric ulcer scores were assigned. Venous blood gas values were also measured.

Results

Gastric ulcers in control horses significantly decreased after 21 days, but there was no difference in ulcer scores when compared to the Egusin® treated horses. NG gastric ulcer scores significantly increased in E-250 and control horses on day 28 compared to day 21 as a result of intermittent feed-deprivation, but no treatment effect was observed. NG ulcer scores remained high in the control group but significantly decreased in the E-SLH- and E-250-treated horses by day 35. Gastric juice pH values were low and variable and no treatment effect was observed. Mean blood pCO₂ values were significantly increased two hours after feeding in treated horses compared to controls, whereas mean blood TCO₂ values increased in the 24 hour sample, but did not exceed 38 mmol/l.

Conclusions

The feed-deprivation model increased NG gastric ulcer severity in the horses. However, by day 35, Egusin^® treated horses had less severe NG gastric ulcers compared to untreated control horses. After 35 days, Egusin^® products tested here ameliorate the severity of gastric ulcers in stall-confined horses after feed stress.

Development and validation of a gas chromatography-flame ionization detection method for quantifying sucrose in equine serum

A simple and accurate method for quantifying sucrose in equine serum that can be applied to sucrose permeability testing in the horse was developed and validated using gas chromatography with flame ionization detection. The assay provided an acceptable degree of linearity, accuracy, and precision at concentrations of sucrose as low as 2.34 μmol/l and as high as 20.45 μmol/l. Percentage recovery of sucrose from serum ranged from 89% to 102%; repeatability and intermediate precision (relative standard deviation) ranged from 3.6% to 6.7% and 4.1% to 9.3%, respectively. The limit of detection was 0.73 μmol/l. No interfering peaks were observed except lactose, which gave 2 peaks, one of which overlapped partially with sucrose. To evaluate the suitability of the method for quantifying sucrose in serum samples from horses with naturally occurring gastric ulceration, 10 horses with and without naturally occurring gastric ulceration were subjected to sucrose permeability testing. All horses demonstrated an increase in serum sucrose concentration over time following oral administration of sucrose; however, the increase from baseline was significant for horses with gastric ulceration at 45 min (P = 0.0082) and 90 min (P = 0.0082) when compared with healthy horses. It was concluded that gas chromatography with flame ionization detection is a valid method for quantifying sucrose in equine serum and can be applied directly to the analysis of sucrose in equine serum as part of a larger validation study aimed at developing a blood test for the diagnosis of gastric ulcers in horses.

Prevalence of gastric ulcers and relationship to other parameters in Standardbred racehorses

Gastric ulcer prevalence rate is reported to be 60-90% in racehorses. This study examined a population of 40 Standardbred horses in race training and assessed the relationship of ulcers to performance history and body condition score (BCS). Forty Standardbreds on two racing facilities in southern Michigan were examined during the last 2 weeks of December 2007 and the second week of January 2008. Age of horses (as of January 1) ranged from 3 to 12 years. Squamous epithelial ulcers were graded (0-4) using an established scoring system during gastroscopic examinations and BCS was recorded (1 to 9 scale). Trainers graded racing performance of each horse on a scale of A to F, with A being best. Horses were grouped according to gender, age, and BCS. Prevalence of ulcers was similar between facilities (50% and 56%) but the mean prevalence (52.5%) was lower than in previous reports. Ulcer score was not related to gender (P=0.84), age (P=0.72), BCS (P=0.64), or performance history (P=0.55). These findings suggest that commonly cited prevalence rates of ulcers may not be consistent for all populations of racehorses. Further, given that less than 20% of the horses examined had an ulcer score grade 2 or higher, the impact that ulcers have on performance may be overestimated in some equine populations. Finally, this study clearly demonstrates that a gastroscopic examination is necessary to determine presence of ulcers, rather than assuming their presence based on decreased performance or low body condition score.

Prevalence of gastric ulcer syndrome in high-level endurance horses

REASONS FOR PERFORMING THE STUDY

Equine gastric ulcers syndrome (EGUS) prevalence studies are rare in the endurance horse and none has been carried out to date in horses competing at high level.

OBJECTIVES

To determine the prevalence of EGUS in high-level endurance horses.

METHODS

Thirty endurance horses competing at high level were selected and submitted to 2 gastroscopic examinations. The first gastroscopy was performed during the interseason period, and the second during the competition season within 2-3 days following a ride of 90-160 km. Data related to housing, feeding, training system as well as age, breed and gender were recorded for each horse.

RESULTS

The prevalence of squamous gastric ulcers was 48% during the interseason period (mean score 0.85 ± 0.13 on a scale from 0-4) and 93% during the competition season (mean score 1.60 ± 1.15) with a highly significant difference between the seasons (P = 0.001). Most of the lesions were situated in the squamous portion of the stomach but 33.3% of horses showed also glandular lesions. Significant influence of training and performance level on the gastric score (according to the distance of the ride preceding the second gastroscopy) was shown (P = 0.038). There was also a significant influence of housing on the gastric score (P = 0.002) showing higher scores in the horses kept totally on pasture (mean score: 2.14 ± 0.14) vs. horses housed in a mixed environment (stable + pasture, mean score: 1.43 ± 0.17). Both the pastured and (stabled + pastured) groups were receiving a grain supplement but the pastured group received a higher daily starch intake, which might explain the higher ulcer prevalence. There was no influence of age, breed or gender on the gastric scores.

CONCLUSIONS

The high prevalence of gastric lesions observed in this study is probably related to the high level of training and performance of the horses examined compared to the population of horses included in the prior study.

POTENTIAL RELEVANCE

This prevalence of EGUS in high-level endurance horses is comparable to the prevalence established in racing horses. The equine veterinarians may take into consideration EGUS as a potential cause of poor performance.

Prevalence of gastric ulceration in Swedish Standardbreds in race training

REASONS FOR PERFORMING STUDY

There is little information about the prevalence of gastric ulcers in Standardbred trotters and potential correlations between ulcers and various traits, e.g. age, sex, performance, temperament and feeding regimens, need further elucidation.

OBJECTIVES

The prevalence of ulcers in the gastric squamous mucosa of Swedish Standardbreds was estimated and the associations between ulcer score and age, sex, performance, temperament and feeding regimens were determined.

METHODS

Eighty Swedish Standardbreds in active race training, trained by 9 different trainers, underwent gastroscopy. Information on age, gender, status of training, performance over the last 4 months compared with the trainer's expectations before that period, behaviour, eating habits, feed type, bedding type, time spent outdoors per day and medical treatment during the last month was collected. Gastroscopy was performed and lesions in the squamous gastric mucosa were scored from 0 to 4 (0 = no lesions; 4 = > 5 lesions with haemorrhage, > 10 lesions with no haemorrhage, or a large area of diffuse loss of surface epithelium).

RESULTS

Twenty-four (30%) of the horses had no lesions in the squamous mucosa, 22 (27.5%) had a score of 1; 21 (26.2%) score 2; 9 (11.2%) score 3; and 4 (5%) score 4. Horses that were in preparatory training and those that had raced during the last month were significantly more affected than horses that were fit for racing but had not raced during the last month, using a logistic regression model with trainer incorporated as a random effect.

CONCLUSIONS

The study confirmed a high prevalence of ulcers in the gastric squamous mucosa of Standardbreds in race training. Of the studied parameters only status of training showed a significant association with gastric ulcers of the squamous mucosa.

POTENTIAL RELEVANCE

Gastric ulceration is a common disease and diagnosis should be made by endoscopic examination of the gastric mucosa, since parameters such as age, gender, performance, behaviour, eating habits provide only weak clues as to which horses might be affected. Further studies are needed to determine the aetiology of the syndrome and to find ways to reduce, if possible, the frequency of gastric ulcers.

Prevalence of gastric squamous ulceration in horses with abdominal pain

REASONS FOR PERFORMING STUDY

Prevalence of gastric ulcerations differs widely according to breed and circumstances of management. Further study of the biological variables involved is required in order to identify more exactly the reasons for the reported range.

OBJECTIVES

The objectives of this present study, which do not appear to have been addressed previously in the literature, were 1) the prevalence of gastric ulceration in horses with abdominal pain. 2) difference in prevalence in horses responding to medical therapy and those requiring surgical intervention. 3) whether gastric ulceration is associated with any particular gastrointestinal tract lesion.

METHODS

Horses were included in the study if gastroscopy was performed within 24 h of presentation. The presence and grade of gastric ulceration was recorded together with the medical records. Data were analysed categorically using a Fisher's exact test or Chi-squared test.

RESULTS

One hundred horses met the selection criteria. Forty-nine percent (49/100) of horses had gastric ulceration, 63% (63/100) responded to medical therapy and 37% (37/100) to surgical intervention, and prevalence was higher in the former (59%) than the latter (32%). Horses with duodenitis-proximal jejunitis (DPJ) had a trend towards higher prevalence of gastric ulceration compared to those with other GI lesions. Sixty-eight percent (13/19) of horses diagnosed with DPJ, 32% (8/25) with a large colon impaction and 14% (1/7) with large colon volvulus had gastric ulceration.

CONCLUSIONS

The presence of gastric ulceration in all horses with abdominal pain was moderate. Horses responding to medical therapy had a higher prevalence of gastric ulceration compared to horses requiring surgery and there was a trend towards higher prevalence in cases of DPJ compared to other GI lesions. There was not a statistically significant difference in gastric ulceration detected between specific lesions, including large colon impactions and large colon volvulus.

POTENTIAL RELEVANCE

The clinical relevance of ulceration is still unclear and further studies are required to differentiate between incidental and clinically important gastric ulceration.

Spontaneous gastroduodenal perforations in dogs: a retrospective study of 15 cases

The clinical findings and outcomes following surgical management of spontaneous gastroduodenal perforations in 15 dogs were reviewed in a retrospective study to identify related risk factors. Clinical and clinicopathological findings were diverse. Use of multiple diagnostic procedures yielded a strong index of suspicion for gastrointestinal perforation. There was a trend towards improved survival for animals with perforation of the gastric fundus/body compared to pyloric or duodenal perforation, although the difference was not statistically significant. Five dogs were euthanased at surgery; two dogs died within two days after surgery. Seven of the eight surviving dogs had a favourable long-term outcome. Previous administration of NSAIDs was the only identified predisposing factor in ten of 10 of the dogs.

Pathomorphological study on gastroduodenal ulceration in horses: localisation of lesions

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 on 71 horses over a period of 24 months. Gastric ulcers were found in 52 horses (73.2%). There was no significant association between age or sex and occurrence of gastric ulcers. In all horses the squamous mucosa lesions were localised near the margo plicatus (100% of the cases), whereas in 23 horses the lesions were near the margo plicatus and lesser curvature and in 7 horses at the greater curvature. In 18 horses the mucosa was affected in the whole extent of the margo plicatus and in 1 horse diffuse lesions of the squamous mucosa were noted. Lesions of the glandular mucosa were localised in 11 horses at the fundic area, in 1 horse they occurred in the pylorus, and in 10 horses diffuse lesions of the glandular mucosa were recorded. A low prevalence of Gasterophilus intestinalis infection was detected (1 horse, 1.4%). We have confirmed that gastric ulcers are a common problem in horses and duodenal or oesophageal ulceration is rare (not a single case of the latter was found in this study). Lesions in the glandular mucosa of the stomach are more frequent in suckling foals than in older animals. Lesions of the glandular mucosa are also common in adult horses, and a complete gastroscopic examination including examination of the pylorus is advisable to evaluate this syndrome.

Equine gastric ulcer syndrome in adult horses: a review

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 disease. The prevalence of the disease in racehorses has been reported to be as high as 100%. In general, horses that are in active training for racing tend to have a prevalence of around 90%, whereas pleasure horses in full work have a reported prevalence of approximately 60%. Emerging diagnostic tests which could obviate the need for gastroscopy are introduced and current recommendations for treatment are summarised, focussing on proton pump inhibitors, in particular omeprazole, administered orally. The oral administration of omeprazole has been shown to be effective in both treating horses with gastric ulceration and at preventing re-occurrence whilst the horses are in training, provided that daily dosing is maintained.

The prevalence of gastric ulceration in racehorses in New Zealand

AIM

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 quality, and presence of clinical signs consistent with equine gastric ulcer syndrome (EGUS) was recorded.

RESULTS

Of the 171 horses in the study, 133 (78%) were Thoroughbreds and 38 (22%) were Standardbreds. Evidence of gastric ulceration was present in 151 (88.3%) of these. Prevalence of ulceration was higher at the lesser curvature (LC) and greater curvature (GC) of the stomach than at the saccus caecus (SC; p<0.01), and ulceration was more severe at the LC than at either the GC (p=0.02) or the SC (p<0.001). The prevalence of ulceration did not differ between the two breeds (p=0.51) or between horses of differing ages (p=0.56). Gastric ulceration was evident in 125/141 (89%) horses kept at pasture for at least 4 h/day, in all 13 (100%) horses kept at pasture full time, and in 16/17 (94%) horses stabled full time. Prevalence and severity of ulceration did not differ between horses stabled full time, kept at pasture for part of the day or kept at pasture full time (p=0.33 and 0.13, respectively), and for horses grazed on pasture severity of ulceration did not vary significantly with the quality of the pasture (p=0.12). Neither prevalence (p=0.26) nor severity (p=0.49) of gastric ulceration varied significantly with duration of training.

CONCLUSIONS

The prevalence of gastric ulceration in racehorses in New Zealand is similar to that reported elsewhere for horses in active training for racing. Access to pasture for some or all of the day did not appear to be protective.

A comparison of two scoring systems for endoscopic grading of gastric ulceration in horses

AIM

To compare two scoring systems for grading gastric ulcers in adult horses.

METHODS

Digitised recordings of gastroscopy examinations of 22 horses that were part of a study on prevalence of gastric ulceration in racehorses in New Zealand were reviewed independently by three examiners. All stomachs were graded by each examiner using two different grading systems, the Equine Gastric Ulcer Council (EGUC) system and the Number/Severity (N/S) system.

RESULTS

All examiners commented that the EGUC system was quicker and easier to use. There was no significant difference between examiners in the grades assigned using the EGUC system (p=0.31) and the agreement between examiners was high (Kappa values of 0. 85(1vs2), 0.88(1vs3) and 0.80(2vs3)). There was a significant difference between examiners in the grades assigned using the severity component of the N/S system (p=0.005).

CONCLUSIONS

The EGUC system was more repeatable, and was faster and easier to use than the N/S system.

CLINICAL RELEVANCE

The EGUC system is suitable as a standard scoring system due to its ease of use, and the repeatability and correlation of grades assigned between independent examiners. Use of a standard scoring system will more easily allow comparisons to be made between different research groups and clinicians.

Epidemiological clues to preventing colic

Colic remains a significant problem in the horse in terms of welfare and economics; in some equine populations it is the single most common cause of death. Many causes of colic are cited in the equestrian and veterinary literature but little scientific evidence exists to substantiate these theories. Recent epidemiological investigations have confirmed that colic is complex and multi-factorial in nature. Studies have identified a number of factors that are associated with increased risk of colic including parasite burden, certain feed types, recent change in feeding practices, stabling, lack of access to pasture and water, increasing exercise and transport. These findings are reviewed together with examples of management practices that may be altered to reduce the incidence of specific types of colic. This is an opinionated, not a systematic, review focusing on those areas that are considered most relevant to the practitioner.

Oral administration of sucrose solutions and measurement of serum sucrose concentrations to evaluate gastric permeability in adult bottlenose dolphins (Tursiops truncatus)

OBJECTIVE

To measure concentrations of sucrose in the serum of captive dolphins after oral administration of a sucrose solution and determine the suitability of this method for use as a test to detect gastric ulcers.

ANIMALS

8 adult captive bottlenose dolphins (Tursiops truncatus).

PROCEDURES

Blood samples were collected from the ventral fluke vein of dolphins before and 45 minutes after oral administration of 500 mL of solution containing 25 or 50 g of sucrose; oral administration was achieved by use of gastric intubation. Serum was separated, diluted in a solution of 90% acetonitrile-to 10% water that contained 10 ng of an internal standard (trichlormethiazide)/microL, mixed, and centrifuged. Supernatant was analyzed by use of liquid chromatography-mass spectrometry-mass spectrometry (LC-MS-MS).

RESULTS

Serum sucrose concentrations of dolphins were at or less than the limits of detection before oral administration. Values after administration of sucrose solution varied among dolphins and were higher and more variable after administration of 50 g, compared with concentrations after administration of 25 g.

CONCLUSIONS AND CLINICAL RELEVANCE

Serum sucrose concentrations in samples collected during routine health evaluations of captive dolphins can be reliably measured by use of LC-MS-MS. Correlating serum sucrose concentrations with endoscopic observations of the gastric mucosa of dolphins will validate this approach for use in screening for the prevalence and severity of gastric ulcers and determining the efficacy of treatment regimens.