The prevalence and distribution of gastric ulceration in 345 racehorses

OBJECTIVE: To report the prevalence and distribution of gastric ulceration within a group of racehorses and to describe the endoscopic appearance of gastric antrum and pyloric ulceration. DESIGN: Retrospective clinical study. PROCEDURE: Medical records from gastroscopic examinations of 345 racehorses (331 Thoroughbreds and 14 Standardbreds) were reviewed. Prevalence, distribution and severity of gastric ulcers were recorded. Lesions involving the squamous mucosa and the glandular mucosa of the antrum and pylorus were graded and compared. RESULTS: Gastric ulceration was found in 86% of racehorses. The squamous mucosa around the margo plicatus was most commonly affected. The pylorus was examined in 175 horses and 47% were ulcerated. No association was found between presence of lesions of the squamous mucosa and those of the pylorus. Low correlation was found between grade and location of lesions, with the pyloric lesion score being significantly less than the squamous mucosal lesion score. CONCLUSION: Gastric ulceration was present in a large proportion of racehorses. The pylorus was also an important site of ulceration. There was no association between presence of lesion at one site and the other, although there was a low correlation between grade of lesion and location, with the pyloric ulcer grade being lower.     

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.     

Gastric ulceration in horses: 91 cases (1987-1990).

Gastroendoscopy was performed on 111 horses (1 to 22 years old) that had signs of abdominal discomfort of variable duration and severity. At least 1 episode of colic had been observed within 48 hours of examination in 31 horses. Recurrent episodes of colic were observed in 28 horses within 2 to 10 days of examination, 31 horses within 11 to 30 days, 12 horses within 31 to 60 days, and in 9 horses at more than 60 days after the initial examination. Gastric ulceration was found in 91 of 111 horses examined. Other abnormalities involving the gastrointestinal tract or other abdominal viscera were not found on examination in 57 of 91 horses with gastric ulcers. The most frequent concurrent abnormalities found in the remaining 34 horses with gastric ulcers were impaction of the large colon (n = 6), colonic tympany (n = 6), peritonitis (n = 6), gastric impaction (n = 4), ileocecal intussusception (n = 3), small-colon impaction (n = 4), and proximal enteritis (n = 2). Thirteen horses with gastric ulceration underwent abdominal surgery, and in 5 horses, lesions were not found at surgery. Gastric ulceration was determined to be the primary cause of colic in 31 horses on the basis of the lack of other abnormalities, clinical response to treatment with histamine type-2 receptor (H2) antagonists, and confirmation of improvement or resolution of gastric ulceration via endoscopy. Gastric ulceration was the suspected cause of colic in 26 other horses on the basis of the lack of other abnormalities, severity of lesions, and clinical response to treatment with H2 antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence of gastric ulcers in show horses.

OBJECTIVE: To determine prevalence and risk factors for gastric ulcers in show horses. DESIGN: Field survey. ANIMALS: 50 horses in active training that had been transported to at least 1 event in the 30 days prior to endoscopy. PROCEDURE: Interview of owner, physical examination, serum biochemical analysis, CBC, and gastric endoscopy were performed. RESULTS: Gastric ulceration was detected in 58% of the horses. Horses with a nervous disposition were more likely to have ulceration than quiet or behaviorally normal horses. Horses with gastric ulceration had significantly lower RBC counts and hemoglobin concentrations than those without ulceration. CONCLUSIONS AND CLINICAL RELEVANCE: Show horses have a high prevalence of gastric ulceration. Lower RBC counts and hemoglobin concentrations may be the result of chronic gastric ulceration.     

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.     

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.     

Idiopathic gastroesophageal reflux disease in an adult horse

Chronic gastroesophageal reflux disease was diagnosed in a 22-year-old female Tennessee Walking Horse that had signs of bruxism and ptyalism. Esophageal ulceration was detected via endoscopy. Compared with the damage to the proximal portions of the esophagus, the severity of the ulceration increased toward the gastroesophageal junction. Esophageal ulceration attributable to chronic gastric acid reflux is usually secondary to pyloric outflow obstruction in horses. In the horse of this report, there was no evidence of either a chronic pyloric or duodenal obstruction that could have resulted in esophageal ulceration. Esophageal ulceration in this horse was attributed to gastroesophageal reflux disease, a common condition in humans in which the underlying abnormality is functional incompetence of the gastroesophageal junction. Treatment is directed at decreasing gastric acidity and protecting the ulcerated mucosa. In the horse of this report, treatment was unsuccessful and the horse was euthanatized; a physical cause of gastroesophageal reflux disease was not identified during an extensive postmortem examination.     

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

OBJECTIVE: To determine associations between age, sex, or medical treatment and prevalence and severity of gastric ulceration in Standardbred racehorses in training. DESIGN: Cross-sectional study. ANIMALS: 224 Standardbred racehorses in training. PROCEDURE: Gastroscopy was performed on each horse, and mucosal ulceration was graded from 0 (normal mucosa, no lesions) to 3 (extensive, often coalescing, lesions with areas of deep ulceration). Associations between age, sex, or treatment and prevalence and severity of ulcers were evaluated. RESULTS: Prevalence of gastric ulceration was 87%. Although there was little association between age and prevalence of ulcers, there was an association between age and severity of ulcers. Most 2-year-old horses (57.7%) had an ulcer score of 0 or 1. In all other age groups, most (58% to 82.61%) of horses had an ulcer score of 2 or 3. Although overall prevalence of ulceration was comparable among sex groups, the relative risk for gastric ulceration increased with age in castrated males, whereas it decreased in females and sexually intact males. CONCLUSIONS AND CLINICAL RELEVANCE: Gastric ulceration is common in Standardbred horses in race training. Severity is higher in horses > or = 3 years of age than in 2-year-old horses. Relative risk for ulceration increases with age in castrated males.     

GASTRIC LYMPHOSARCOMA IN A DOG: A CASE REPORT

A 9-year-old female spayed mixed-breed dog was presented with a ten-week history of vomiting. A survey abdominal radiograph showed a soft tissue mass on the lesser curvature of the stomach and an adjacent thickened greater curvature. A barium contrast study confirmed the presence of this mass. The radiographic diagnosis was gastric tumor. Radiographic signs of gastric neoplasia include soft tissue masses or thickening of the stomach wall, delayed gastric emptying, immobility of portions of the stomach wall, and residual stomach-wall staining by barium. Necropsy revealed a gastric lymphosarcoma that had infiltrated the entire circumference of the pyloric antrum. The most common gastric malignancy in the dog is adenocarcinoma. Gastric lymphosarcoma is considered rare.     

Post-mortem findings of gastric ulcers in Swedish horses up to one year of age: a retrospective study 1924-1996

Necropsy records from 702 horses, less than one year old, that were subjected to necropsy between 1924 and 1996 were used to estimate the prevalence of gastric ulceration in younger horses and to evaluate some potential risk factors that may contribute to the development of gastric ulceration. Information concerning breed, gender, age, season of death, clinical signs of colic, medical treatment, parasitism and documentation of diseases in different organs were recorded, as well as size, number and anatomical distribution of ulcers. Gastric ulcers were found in 96 of 702 young horses (14%) and gastritis in another 64 animals (9%). The cutaneous region adjacent to margo plicatus (51%), and the corpus region were commonly affected (46%). The investigation clearly demonstrates that gastric ulceration has affected young Swedish horses to a similar degree during most of the 20th century. A significant (p < or = 0.05) association between gastric ulcers and the signs of colic, parasitism and a concomitant intestinal, liver, and oesophageal involvement was found. No breed or sex predilection with gastric ulcers was obtained. The risk of gastric ulcers was highest during the fall (odds ratio 3.52) and lowest during the summer (odds ratio 0.45). The seasonal variation could not be explained by concomitant findings of Gasterophilus larvae. By using a multivariate logistic regression analysis, only season significantly influenced the risk of gastric ulceration.     

Postmortem findings of gastric ulcers in Swedish horses older than age one year: a retrospective study of 3715 horses (1924-1996)

The present study was performed to estimate retrospectively the prevalence of gastric ulceration in necropsied Swedish horses and to evaluate some potential risk factors. Horses (n = 3715) older than age one year and necropsied 1924-1996 were included. Information about breed, gender, age, season of death, clinical signs of colic, Gasterophilus larvae and documentation of diseases in different organs was recorded. Data on size, number and anatomical distribution of gastric ulcers were also obtained. The cold-blooded horses and the Standardbreds were the 2 most dominating breeds in our material. Gastric ulcers/erosions were seen in 633 (17%) of the horses. The highest prevalence was found in Thoroughbreds (19%) and Standardbreds (19%), whereas only 7% of the cold-blooded horses were affected. The cutaneous region along the margo plicatus was the most commonly affected area (52%). Multiple ulcers were seen in 62% of the horses with gastric ulcers and concurrent ulcers in the oesophagus were reported in 6%. In the bivariate analysis, significant associations were found between gastric ulcers and signs of colic (P<0.001) and gender (P<0.001), as well as between concomitant bowel (P<0.001), liver (P<0.05) and oesophageal (P<0.01) lesions. Using a multivariate logistic regression model, only year of necropsy and breed were found significantly to influence the risk of gastric ulceration by decreasing the Log Likelihood test value. The present study shows clearly that gastric ulceration has been present in Swedish horses throughout the 20th century, which also may be the situation worldwide.     

Sucrose concentration in blood: a new method for assessment of gastric permeability in horses with gastric ulceration

A urine sucrose test has recently been reported to be a reliable method of detecting gastric ulcers in horses; however, technical difficulties associated with urine collection have limited the practical value of the test. The objective of this pilot study was to determine whether gastric sucrose permeability, as evaluated by serum sucrose concentration, could be used to detect gastric mucosal injury in horses. Twelve adult horses with naturally acquired gastric ulceration were studied. After a 20-hour nonfeeding period, each horse was dosed with 250 g of sucrose via nasogastric intubation. Blood samples were collected at 0, 15, 30, 45, 60, and 90 minutes, and horses underwent gastroscopy 4 hours later. The severity of gastric ulceration in each horse was defined by means of a 4-point ulcer-scoring system, and the relationship with serum sucrose concentration was analyzed by means of a linear mixed-effects model. Serum sucrose concentration was measured by liquid chromatography operating in tandem with electrospray mass spectrometry. After nasogastric administration of table sugar, horses with moderate to severe gastric ulceration had significant increase in serum sucrose concentration at 30, 45, 60, and 90 minutes, relative to earlier times (P < .05). Peak sucrose concentration was observed at 45 minutes, and was correlated with ulcer severity (Spearman's rank correlation coefficient = 0.898, P < .05). These data indicate that determination of sucrose concentration in equine serum may be a useful test for identifying horses with endoscopically visible gastric ulceration and has potential use as a noninvasive method for screening and monitoring horses engaged in racing training and other performance-related disciplines.     

Gastric impaction associated with displacement and volvulus of the large colon in seven mature horses

Gastric impaction associated with large colon volvulus (LCV) was identified in seven horses. Right dorsal displacement of the large colon and suspected nephrosplenic entrapment was identified in 2 of the 7 horses as well as LCV with concurrent gastric impaction. All horses underwent surgery for LCV and none survived. Five horses died or were subjected to euthanasia intraoperatively or in recovery. One horse was subjected to euthanasia post operatively due to persistent gastric reflux, following resolution of the gastric impaction. One horse was subjected to euthanasia post operatively due to a suspected gastric rupture, which was confirmed on post mortem examination. It is hypothesised that a large mass in the cranial abdomen, such as a gastric impaction may disrupt the normal anatomical large colon alignment or may cause colonic motility or microbiota alterations, and thus increase the risk of large colon displacement and volvulus.     

Prevalence of Gastric Ulcerations in Horses with Colic

The goal of this study was to determine the prevalence of gastric ulcers in horses with acute abdominal crisis (colic) and to examine the temporal effect of hospitalization on ulcer development in equine patients treated for colic. In addition, other factors that may be associated with gastric ulceration were also explored. The study design was a prospective original study incorporating 169 horses that presented to the George D. Widener Hospital for examination. One hundred and twelve horses presenting with the chief complaint of colic were included in the study group, and 57 horses that presented for non-colic or nonemergency complaints were evaluated and included as case controls. Gastroscopy was performed on equine patients presenting with the chief complaint of colic or horses presenting for reasons other than colic (control); mucosal changes were scored 0 to 3. Additionally, horses presenting for colic were gastroscopically evaluated twice during a 5-day period. Medical records were reviewed for history, clinical findings, laboratory results, and treatment. Seventy-six of 112 horses presenting with the chief complaint of colic had gastric ulceration compared with 41 of 57 horses in the control group. There was a significant association between age of the patient and chief complaint (ie, colic vs control) and between breed and chief complaint. There was no association between gastric ulcer score and chief complaint (colic vs control). Thirty-eight of the 112 horses presenting with colic deteriorated in ulcer score while hospitalized. Using a Pearson chi-squared test, there was no statistically significant association between gastric ulceration with age, breed, or sex. Horses with gastric ulceration in the colic group had lower packed cell volumes compared with horses presenting with colic without gastric ulcers, and this was statistically significant (P < .001). The high incidence of gastric ulceration in the study and control groups supports the reports of other investigators that gastric ulcers in horses, no matter the presenting complaint, are widespread. There was a significant association between breed and chief complaint (P = .005); however, breed and outcome of gastric ulceration were not related (Thoroughbreds were the least likely breed to present for colic). Although a trend in increasing gastric ulceration was seen in hospitalized colic patients, it was not statistically significant. This suggests that horses that are hospitalized may be at increased risk for developing gastric ulcers because of stress, feed deprivation, and administration of treatment. Thus, horses that present for colic should be gastroscopically evaluated if clinical signs raise the index of suspicion for gastric ulceration.     

Squamous gastric ulceration complicated by gastric stenosis in a foal

A 2-month-old Warmblood colt presented with recurrent colic and regurgitation. Gastroscopy, performed on several occasions, and barium-contrast radiography revealed severe squamous gastric ulceration and stenosis at the level of the margo plicatus. Treatment with omeprazole reduced the extent and severity of the gastric ulcers but did not affect the stenosis. The foal was euthanised because of a poor prognosis, and post-mortem examination confirmed the clinical diagnosis. Severe squamous gastric ulceration, granulation tissue formation and cicatrisation of deep gastric lesions were considered to have caused the stenosis. Gastroduodenal outflow obstruction is a recognised disorder in foals, but stenosis at the level of the margo plicatus has not been reported in foals or adult horses. To the authors' knowledge, this is the first case of severe squamous gastric ulceration, complicated by stenosis at the level of the margo plicatus, in a foal. Although rare, gastric stenosis should be considered in foals suffering recurrent colic and regurgitation.     

A Botanical-Based Equine Nutraceutical Reduces Gastric Smooth Muscle Contractile Force In Vitro

The objective of this study was to evaluate the effect of a botanical-based equine nutraceutical on contractility of gastric smooth muscle in vitro. Gastric ulcers are prevalent in performance horses and negatively impact horse welfare. Gastric hypermotility has been positively associated with the development of gastric ulceration in nonequine species, and reduction of hypermotility may be protective against their development. Stomachs from 12 pigs processed for food at a provincially inspected abattoir were collected within 1 hour of slaughter. Explants of nonglandular gastric tissue were prepared and suspended in a tissue bath, attached to a force transducer, in the presence or absence of a simulated digest extract of the nutraceutical. Tissue was stimulated to contract using increasing doses of acetylcholine. Peak and mean contractile force over 1 and 2 minutes after exposure to acetylcholine were measured. Exposure of gastric smooth muscle to the nutraceutical significantly reduced contractility of the tissue. These data provide support for the use of this nutraceutical to reduce contractility of nonglandular gastric smooth muscle and may indicate a protective effect of this nutraceutical in horses with mechanically induced gastric ulcers. Future studies are needed to clarify the role of gastric hypermotility on development of equine gastric ulcers and to determine the effect of this nutraceutical on equine gastric contractility and ulcerogenesis in vivo.     

Heineke–Mikulicz pyloroplasty for the treatment of pyloric stenosis secondary to gastro-duodenal ulcer disease in three foals

The objective of the study was to describe a modified Heineke–Mikulicz pyloroplasty for the treatment of pyloric stenosis in foals due to gastric ulceration and assess the short- and long-term outcome of foals receiving the pyloroplasty. Medical records of foals undergoing a modified Heineke–Mikulicz pyloroplasty due to gastric outflow obstruction secondary to a pyloric stenosis were included in this retrospective case series. The pyloroplasty consisted of an oral to aboral full thickness longitudinal incision on the ventral aspect of the pylorus and proximal duodenum, which was sutured closed with 0 polydioxanone in a transverse orientation, thereby, enlarging the pyloric lumen diameter. Long-term outcome was obtained from medical and race records. The pyloroplasty was successfully performed in three foals with a surgical time of 95–121 min, with immediate return to nursing and hospital stay of 4–14 days. Complications included a small intestinal volvulus and intra-abdominal adhesions in a foal that did not survive. Another foal had an incisional infection. Two of the three foals went on to race. It was concluded that the pyloroplasty procedure is an acceptable option for the treatment of pyloric stenosis and secondary gastric outflow obstruction due to gastric ulceration. The limited amount of bowel manipulation with no change in intestinal flow, along with the successful outcomes achieved, make this another surgical option available for the correction of pyloric stenosis in foals.     

Gastric squamous cell carcinoma in the horse: Seven cases (2009–2019)

This report describes gastric squamous cell carcinoma (GSCC) in seven horses. It records the clinical signs, treatment and outcomes. Main clinical signs were mostly nonspecific and included weight loss, anorexia, fever, tachycardia and tachypnoea. Some more suggestive clinical signs were observed such as recurrent choke, halitosis and hypersalivation. Chronic anaemia and hypoalbuminaemia were common findings. Gastroscopy identified a gastric mass in four cases (57.1%); however, visualisation of the stomach was precluded in the other three horses due to distal oesophageal neoplastic infiltration and compression. Gastric wall thickening was noticed using abdominal ultrasonography in four horses (57.1%). Neoplastic cells could only be detected in the peritoneal fluid of 2 out of 7 horses. Endoscopic-guided or transabdominal ultrasound-guided biopsies allowed an ante-mortem diagnosis in three horses (42.8%). Gastric masses were identified at post-mortem examination and metastasis were confirmed in the liver and/or the spleen for 4/4 cases. In the cases for which palliative therapy was attempted, most of the horses were subjected to euthanasia within 4 weeks. In conclusion, GSCC is an uncommon neoplastic disease in horses. A combination of diagnostic tests is often necessary to achieve a diagnosis, which is frequently only made late in the course of the disease. As a result, GSCC is commonly associated with a poor short-term prognosis.     

Evaluation of the effect of ranitidine on gastroduodenal contractile activity and gastric emptying in horses

Objective-To determine the effect of ranitidine on gastric emptying in horses. Animals-11 adult horses. Procedures-In vitro, isolated muscle strips from the pyloric antrum and duodenum of 5 horses were suspended in baths and attached to isometric force transducers. Once stable spontaneous contractions were observed, ranitidine or diluent was added at cumulative increasing concentrations. Isometric stress responses were compared. In vivo, 6 horses were assigned to a group in a prospective randomized crossover study design with a wash-out period of 2 weeks between trials. Ranitidine (2.2 mg/kg) or saline (0.9% NaCl) solution was administered IV, and 15 minutes later, acetaminophen (20 mg/kg), diluted in 400 mL of water, was administered via nasogastric tube to evaluate the liquid phase of gastric emptying. Serum acetaminophen concentration was measured at several time points for 3 hours by use of liquid chromatography tandem mass spectrometry. Frequency of defecation was recorded during the 3 hours of the study. Results-Ranitidine increased the contractile activity of the pyloric antrum smooth muscle at a concentration of 10(4) M. No significant effect of ranitidine on plasma kinetics of acetaminophen was identified. Frequency of defecation did not differ between groups. Conclusions and Clinical Relevance-Ranitidine did increase gastric motility in vitro, but no effect on liquid phase gastric emptying was identified in healthy horses by use of the acetaminophen absorption model. Results do not support the use of ranitidine to promote gastric emptying.     

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

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