Mucosal lesions in the pyloric area – retrospective study on 315 equine patients (2004 – 2013)

Abstract

In equine medicine the equine gastric ulcer syndrome (EGUS) is known as an important cause of colic, anorexia, weight loss and poor performance. The equine squamous gastric disease (ESGD) is understood quite well and treated successfully whereas a lot of questions remain concerning gastric lesions located in the glandular mucosa, referred to as equine glandular gastric disease (EGGD). The aim of this study was to determine the prevalence of EGGD in the pyloric area in equine patients. Correlations between lesions in squamous and glandular mucosa were investigated and follow-up examinations were analysed to evaluate the development of mucosal lesions in the pyloric area over a certain period. Images and videos recorded during gastroscopy of 315 equine patients between 2004 and 2013 were studied retrospectively. The scoring system (grade 0-4) recommended by the Equine Gastric Ulcer Council was used to assess mucosal lesions separately for squamous mucosa, glandular mucosa of the gastric fundus and mucosa of the pyloric area. The study population included all age groups (median 9,6 years) and a large variety of breeds with most of the horses being warmbloods (214 horses). There were 135 geldings, 133 fillys and mares and 45 colts and stallions. For 263 horses data regarding their level of performance was available with 182 horses being on light work at most, 70 horses being used for medium work and 11 horses classified as high-performance horses. For nine horses data of a follow-up gastroscopy not later than 42 days after the first gastroscopy was available. The assessment of the pylorus was possible in 262 patients (83,2%). Lesions consistent with EGGD grade >= 2 in the pyloric area were found in 98/262 horses with a resulting prevalence of 37,4%. The prevalence of ESGD grade >= 2 was 66,1% and 15,8% of the horses had lesions grade in the glandular mucosa of the gastric fundus. The scores found in the pyloric area were significantly higher than in the glandular mucosa of the gastric fundus. A significant correlation was found between the presence of mucosal lesions grade >= 2 at the pylorus and performance level with 72,7% of high-performance horses being affected compared to only 34,0% of horses just used for light work. A trend of increasing EGUS-score with increase in performance level was visible, but not significant. No significant correlations between pyloric mucosal lesions and age, sex or breed were found. Weak correlations were found between the occurrence of EGGD in the pyloric area and ESGD as well as between EGGD in the pyloric area and EGGD in the gastric fundus. The follow-up examinations revealed no significant changes in EGUS-score of lesions located in the pyloric area, but have to be interpreted carefully due to the retrospective character of this study including a period of ten years, different treatment and management and variable intervals between first and second gastroscopy. We conclude that mucosal lesions in the pyloric area, occurring with a prevalence of 37,4% for lesions grade are a notable problem in equine patients which is why it is essential to examine the pylorus during gastroscopy for an appropriate assessment of the entire equine stomach. High performance horses should be considered at risk for EGGD in the pyloric area and even a moderately increased level of performance consistent with non-professional equine sport may result in an increased risk for pyloric mucosal lesions.