Prevalence of ulcers of the squamous gastric mucosa in standardbred horses

This study was performed to determine the prevalence of ulcers in the gastric squamous mucosa in Standardbred racehorses. Observations were performed at monthly intervals between the beginning of their training season and their 1st qualifying race. This study also identified risk factors at different levels of race training. Forty-eight Standardbred racehorses from 3 training stables in Quebec, Canada, were studied. Baseline historical information and gastroscopic findings were recorded at the beginning of the trial, and once a month thereafter, between December 2001 and June 2002, until the horse's 1st qualifying race or the end of the training. Intensity of training ranged from jogging to intensive training just before the 1st race and was assigned an ordinal score. Location of squamous ulcers and their appearance were observed on gastroscopy, and an ordinal score was assigned. Prevalence of squamous ulcers from the 2nd through the 4th month (72-88%) of training remained at a significantly higher level (P = .002 to .04) than at the onset of the study (38%) and was also higher in intensely trained horses than in joggers (93% versus 56%). Moderate or more intensive training increased the odds (odds ratio [OR], 3.39; confidence interval [CI], 1.34-8.56; and OR, 11.4; CI, 3.21-40.5, respectively) of detecting ulcers with higher scores. These odds were also higher in trotters (OR, 2.17; CI, 1.07-4.43) than in pacers and generally increased with the duration of training. Duration of training, training level, and gait type also influenced the number of sites with ulcers in the same way. Ulcers had higher scores along the lesser curvature (LC) and the margo plicatus (MP) areas of the stomach. It was concluded that squamous ulcers appeared early in the training of Standardbred racehorses, that the number of sites affected and the ulcer score are related to the intensity of training, and that trotters are more prone to squamous ulcers than pacers.     

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.     

Evaluation of diet as a cause of gastric ulcers in horses

OBJECTIVE: To measure pH, volatile fatty acid (VFA) concentrations, and lactate concentrations in stomach contents and determine number and severity of gastric lesions in horses fed bromegrass hay and alfalfa hay-grain diets. ANIMALS: Six 7-year-old horses. PROCEDURE: A gastric cannula was inserted in each horse. Horses were fed each diet, using a randomized crossover design. Stomach contents were collected immediately after feeding and 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after feeding on day 14. The pH and VFA and lactate concentrations were measured in gastric juice Number and severity of gastric lesions were scored during endoscopic examinations. RESULTS: The alfalfa hay-grain diet caused significantly higher pH in gastric juice during the first 5 hours after feeding, compared with that for bromegrass hay. Concentrations of acetic, propionic, and isovaleric acid were significantly higher in gastric juice, and number and severity of nonglandular squamous gastric lesions were significantly lower in horses fed alfalfa hay-grain. Valeric acid, butyric acid, and propionic acid concentrations and pH were useful in predicting severity of nonglandular squamous gastric lesions in horses fed alfalfa hay-grain, whereas valeric acid concentrations and butyric acid were useful in predicting severity of those lesions in horses fed bromegrass hay. CONCLUSIONS AND CLINICAL RELEVANCE: An alfalfa hay-grain diet induced significantly higher pH and VFA concentrations in gastric juice than did bromegrass hay. However, number and severity of nonglandular squamous gastric lesions were significantly lower in horses fed alfalfa hay-grain. An alfalfa hay-grain diet may buffer stomach acid in horses.     

Prevalence of gastric ulcers in endurance horses--a preliminary report

Gastric endoscopy was performed at the end of a 50 or 80 km endurance ride. Gastric ulceration was evident in 67% of the horses with ulcers on the squamous region of the stomach found in 57% of the horses and active bleeding of the glandular mucosa in 27%. Three horses (10%) had lesions only on the glandular mucosa. Values of albumin, creatinine and glucose were higher in horses without gastric lesions. We conclude that horses from endurance competitions have a high prevalence of gastric ulceration that is similar to that observed in performance horses. However the severity of ulceration is less severe than has been reported in Thoroughbred race horses in active training. Owners should be aware of the high prevalence of gastric ulceration in horses that perform in endurance competitions. The high incidence of active bleeding from the glandular mucosa of the stomach in these horses requires further investigation.     

Evaluation of urine sucrose concentration for detection of gastric ulcers in horses

OBJECTIVE: To evaluate the use of sucrose permeability testing to detect ulcers in the gastric squamous mucosa of horses. ANIMALS: 13 adult horses ranging from 5 to 19 years of age. PROCEDURE: Following induction of gastric ulcers by intermittent feed deprivation, horses underwent sucrose permeability testing (administration of sucrose by nasogastric intubation followed by collection of urine at 2 and 4 hours after intubation) and gastric endoscopy. Squamous ulcers were assigned a severity score (range, 0 to 3) by use of an established scoring system. Horses were subsequently administered omeprazole for 21 days, and sucrose testing and endoscopy were repeated. Pair-wise comparisons of urine sucrose concentration were made between horses with induced ulcers before and after omeprazole treatment. Urine sucrose concentrations also were compared on the basis of ulcer severity score. RESULTS: Urine sucrose concentrations and ulcer severity scores were significantly higher in horses with induced ulcers before omeprazole treatment than after treatment. Urine sucrose concentrations were significantly higher for horses with ulcer severity scores > 1. Use of a cut-point value of 0.7 mg/mL revealed that the apparent sensitivity and specificity of sucrose permeability testing to detect ulcers with severity scores > 1 was 83% and 90%, respectively. Results were similar after adjusting sucrose concentrations for urine osmolality. CONCLUSIONS AND CLINICAL RELEVANCE: Urine sucrose concentration appears to be a reliable but imperfect indicator of gastric squamous ulcers in horses. Sucrose permeability testing may provide a simple, noninvasive test to detect and monitor gastric ulcers in horses.     

A study of gastric mucosal pH and its correlation with gastric ulcers in adult horses

In a sample of twenty adult horses' stomachs, the mucosal surface pH was measured at 14 different loci, immediately post mortem, using a pH probe. The squamous epithelium of the pars oesophagea was observed to show a lower pH than the glandular mucosa. The pH of the glandular mucosa was generally uniform whereas within the pars oesophagea the different loci were observed to show variation, the lowest readings being found where the squamous epithelium adjoins the margo plicatus, the same area where ulceration initially tends to occur.

Ten horses in the sample showed moderate to severe ulceration and these horses had significantly lower pH readings compared to the group with mild to no ulceration.     

Prevalence and treatment of gastric ulcers in Thoroughbred racehorses of Korea

BackgroundGastric ulcer is one of the prevalent diseases in racehorses. However, it has not been recognized as important in Korea, and drugs used to treat gastric ulcers are included in the doping test list, so they are not allowed to be administered to racehorses in training.ObjectivesThis study was performed 1) to investigate the prevalence and the severity of gastric ulcers in Thoroughbred racehorses in Korea, 2) to confirm the therapeutic effect of ranitidine and omeprazole, and 3) to compare the efficacy between ranitidine and omeprazole.MethodsForty-nine horses were randomly recruited, and gastroscopy was performed within two days after racing. Twelve horses with a sum grade of five or higher were randomly assigned to two treatment groups. Seven horses were administered ranitidine, and five horses were administered omeprazole. Follow-up gastroscopy was scheduled within one to five days after finishing the treatment.ResultsThe prevalence of gastric ulcer in Korean Thoroughbred racehorses after racing was 100%, and the grade was more severe in the non-glandular region than in the pyloric region. There was no correlation between the severity of gastric ulcer in the two regions. Omeprazole had a greater therapeutic effect than ranitidine.ConclusionsThis study shows the importance of recognizing gastric ulcers as an important factor, and omeprazole as a possible treatment option in Korea, as it has been removed from the list of prohibited substances for racehorses. Thus, the use of omeprazole is currently recommended until one day before the race.     

Efficacy of omeprazole paste for prevention of gastric ulcers in horses in race training

OBJECTIVE: To determine the minimal effective dosage of omeprazole oral paste for the prevention of naturally occurring ulcers in horses starting race training. DESIGN: Prospective study. ANIMALS: 175 horses. PROCEDURE: Horses in the dose selection portion of the study were sham dose treated or received 1 mg (0.45 mg/lb) or 2 mg (0.9 mg/lb) of omeprazole/kg, PO, every 24 hours for 28 days or 4 mg of omeprazole/kg (1.8 mg/lb; loading dose), PO, every 24 hours for 4 days, then 1 or 2 mg of omeprazole/kg, PO, every 24 hours for 24 days. Horses in the dose confirmation portion of the study were sham dose treated or received 1 mg of omeprazole/kg, PO, every 24 hours for 28 days. Gastric ulcer scores at the beginning and end of the study were compared. RESULTS: Sham-dose-treated horses had significantly higher ulcer scores than did horses treated with any of the omeprazole dosages evaluated. Among horses treated with omeprazole, there was no significant interaction of dose (1 or 2 mg/kg) and loading dose; therefore, the lowest effective dose (1 mg/kg) was evaluated in the dose confirmation portion of the study. In the dose confirmation study, 4 of 39 (10%) sham-dose-treated horses remained ulcer free, which was significantly different from the proportion of horses (31/38 [82%]) receiving 1 mg of omeprazole/kg that remained ulcer free. CONCLUSIONS AND CLINICAL RELEVANCE; Results indicated that omeprazole administered at a dosage of 1 mg/kg, PO, every 24 hours for 28 days was effective for prevention of gastric ulcers in horses starting race training.     

Prevalence of gastric ulcers in Thoroughbred broodmares in pasture: a preliminary report

Gastroscopic examinations were performed in 62 Thoroughbred broodmares (33 pregnant, 29 non-pregnant) at one breeding farm to investigate the prevalence of gastric ulceration. Age, pregnancy status, race earnings, last race start, herd size, medical history, number of live foals, breeding years, feed type and number of feedings were recorded, plus coat condition and body condition score were determined. Twenty-one mares were re-evaluated after foaling, and the foaling date, foal weight at birth and placenta weight were recorded.The overall prevalence of gastric ulcers was 70.9%, with a median ulcer score of 3.0 (range: 2–5). Most ulcers were present on the squamous portion of the stomach, while two mares had glandular ulcers. There were no differences in the presence, location and severity of gastric ulcers between pregnant and non-pregnant mares. Furthermore, there were no significant associations between the variables measured and the presence of gastric ulceration. The prevalence of gastric ulceration in this specific population of horses was higher than expected and further investigation is warranted to determine the factors that contributed to this finding.     

Indolent-like corneal ulcers in 3 horses

Three horses were admitted with indolent-like corneal ulcers. All horses were treated topically with antibiotics. Two horses had ulcers with redundant epithelial borders, which were debrided with cotton-tipped applicators after topical anesthesia was induced. One ulcer healed after 2 debridements. Of 2 horses treated surgically, one had complications.     

Efficacy of omeprazole paste for prevention of recurrence of gastric ulcers in horses in race training

OBJECTIVE: To determine whether omeprazole oral paste administered at a dosage of 0.5 or 1 mg/kg (0.23 or 0.45 mg/lb), PO, every 24 hours would effectively prevent the recurrence of gastric ulcers in horses in race training. DESIGN: Prospective study. ANIMALS: 135 horses. PROCEDURES: Horses with gastric ulcers were treated with omeprazole at a dosage of 4 mg/kg (1.8 mg/lb), PO, every 24 hours for 28 days. Horses in the dose selection portion of the study were sham dose treated or received 0.5 or 1 mg of omeprazole/kg, PO, every 24 hours for an additional 28 days. Horses in the dose confirmation portion of the study were sham dose treated or received 1 mg of omeprazole/kg, PO, every 24 hours for an additional 28 days. Gastric ulcers were scored before and after the preventive phase of the study (day 28 to day 56) via gastroscopy, and ulcer scores were compared. RESULTS: Sham-dose-treated horses and horses receiving 0.5 mg of omeprazole/kg had significantly higher ulcer scores than did horses receiving 1 mg of omeprazole/kg. There was a significant difference between the proportion of horses receiving 1 mg of omeprazole/kg (38/48 179%]) that remained ulcer free and the proportion of sham-dose-treated horses (7/44 [16%]) that remained ulcer free. CONCLUSIONS AND CLINICAL RELEVANCE: Omeprazole oral paste administered at a dosage of 1 mg/kg, PO, every 24 hours for 28 days was effective for prevention of recurrence of gastric ulcers in horses in race training.     

Effect of a novel rice fermented extract on gastric ulcers in horses

Gastric ulcers cause appetite loss, poor body condition, and colic in horses. This study investigated the protective effect of a rice fermented extract on the gastric mucosa in 17 healthy Thoroughbreds. For one month, horses in the rice fermented extract (nine horses) and control (eight horses) groups were orally administered a rice fermented extract (100%; 0.2 ml/kg, SID) and tap water (0.2 ml/kg), respectively. Gastric endoscopic images were obtained before and one month after rice fermented extract administration. The gastric ulcer score was lower after administration (median, 1; maximum, 2; minimum, 1) than before administration (median, 4; maximum, 4; minimum, 3) in the rice fermented extract group (P<0.05). In conclusion, the administration of a rice fermented extract for one month improves gastric mucosal lesions in Thoroughbreds with gastric ulcers.