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 & GE;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 & LE; 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.

Automated summary

This study investigated the prevalence of mule gastric ulcer syndrome (MGUS) in a population of mules in Colombia and its potential associations with work load, work type, diet, sex, age, and body condition score. The results showed that the frequency of MGUS in the study population was 42%, with most ulcers located in the squamous region of the stomach. Work load was found to be the only variable associated with the presence of MGUS and mule squamous gastric disease (MSGD). However, no significant risk assessment results were obtained, and no significant interactions among the other variables were observed.