Lymphocytic-Plasmacytic Enteritis (LPE) is an uncommon cause of chronic inflammatory bowel disease in horses. The proliferative inflammatory cell infiltrate results in diffuse mucosal inflammation and impaired nutrients absorption, leading to chronic weight loss, recurrent abdominal pain and hypoproteinemia. This article reports the case of a 25-year-old horse with LPE causing long-lasting severe cachexia and recurrent colic episodes. A positive response to diet changes and medical treatment with corticosteroids was observed during a short period of time. However, relapse of recurrent colic episodes refractory to medical treatment determined the euthanasia of the horse.