Chronic oesophagitis in the cat

Background: Our understanding of the pathophysiology of gastro-oesophageal reflux disease (GERD) in man is limited. The aim of the present study was t o establish a long-term (>1 year) animal model for reflux oesophagitis whic h would allow us to study various aspects of the development of chronic ref lux oesophagitis. Methods: Myotomy was carried out in the gastro-oesophagea l junction in eight cats; seven other cats were sham-operated. Before the o peration, and every 2 months thereafter, oesophagoscopy was carried out, bi opsies were taken for histology, and manometry was performed to determine t he lower oesophageal sphincter pressure (LESP). The cats were killed 1 year after the operation. Results: The myotomy operation resulted in a signific antly decreased LESP. In oesophageal biopsies from these cats, there was a varying degree of oesophagitis starting already 2 months after surgery. In six of the eight myotomized cats there was hyperplasia of the stratum basal e, and cardiac type metaplasia was observed in two cats. The control cats s howed no significant changes in LESP or in the histology of the oesophagus. Conclusions: In cats followed for more than a year, myotomy in the gastro- oesophageal junction results in reflux oesophagitis similar to that seen in patients with chronic gastro-oesophageal reflux.