Chronic gastric dilatation in horses: Diagnosis, treatment and feeding management - A survey of 20 clinical cases

Abstract

Chronic gastric dilatation is a rarely diagnosed disease of the horse. The objective of this report was to describe the clinical and ultrasonographic findings of 20 cases of chronic gastric dilatation in horses. Furthermore, horses' clinical history, signalment and clinical and gastroscopic findings were recorded. Medication, feeding management and outcome are presented. Inclusion criteria were: 1) Clinical signs of recurrent abdominal discomfort or resistance to the riders leg; 2a) Repeated ultrasonographic finding of an enlarged stomach (more than five intercostal spaces), or alternatively; 2b) Repeated gastroscopic finding of an impacted stomach in combination with a subsequent sonographical confirmation; 3a) No gastric emptying following 12 hours of starvation, or 3b) Emptying but repeated episodes of dilatation following normal feeding regime; 4) Exclusion of acute gastric impactions and other gastrointestinal disorders. All horses had shown one or several of the following symptoms: repeated signs of discomfort, recurrent mild or moderate acute colic, defensive reaction when fixing the girth or against the riders left leg, chronic weight loss, poor performance and more. With exception of the rectal examination, clinical and laboratory examination was not conclusive. 19 horses showed an enlarged stomach at initial sonography (range: six to eleven intercostal spaces). The initial examination in one horse referred to our clinic was merely by gastroscopy. Gastroscopy was performed in eleven cases. The horses were treated with metoclopramide hydrochloride (0.1-0.15 mg/kg twice daily p.o.) and feeding management was adapted according to nutritionist's or veterinarian's recommendations. The mean duration of treatment was 16 months at submission of the manuscript. No side effects were observed. Seventeen of the treated horses survived in the long term. One horse was euthanized 10 days after start of treatment with metoclopramide hydrochloride, at the request of the owner as he had noticed no clinical improvement in that period of time. Two horses were euthanized because of orthopedic problems. Fifteen horses showed complete, and four horses partial clinical improvement after treatment and feeding management was adapted. Metoclopramide hydrochloride seemed effective for the long-term treatment of chronic gastric dilatation. Long-term administration of metoclopramide hydrochloride could be an alternative to bethanechol. Further studies are needed to determine the exact pathophysiologic mechanisms of chronic gastric dilatation and to determine the exact diagnostic findings related to different disease states.