Pathogenesis of equine squamous and glandular gastric disease

Abstract

Recent publications have cast light on the marked differences between diseases in the squamous and glandular regions of the equine stomach. Until recently the focus regarding all aspects of gastric disease has been on disease of the squamous mucosa and findings have then been extrapolated to disease in the glandular region. Disease of the squamous mucosa is caused by acid and results in hyperkeratosis, erosions and ulceration. Many of the risks for development of squamous disease relate to factors that allow or promote a more acidic gastric pH or increase exposure of the squamous mucosa to this acid. We know that this is not the case for the glandular mucosa as the epithelial cells in this region in health have protective factors against acid. We now know that disease in the glandular region is inflammatory in origin and not ulcerative. It is proposed that the inciting cause to this lesion is reduced gastric glandular blood flow and it is speculated that it may be an extension of idiopathic inflammatory bowel disease; acid may then slow or inhibit healing. Lesions in the glandular mucosa vary in appearance and these differences may relate to differing aetiologies. Recommendations for management changes are different to squamous disease and primarily involve minimising stress. Treatment for glandular disease is more challenging, healing may take longer and requires alternative approaches to oral omeprazole monotherapy when compared with squamous disease.