Introduction

Gastric Intestinal metaplasia (IM) is defined as the replacement of gastric mucous cells with an epithelium similar to that of the small intestine. IM has been classified as complete (type I) or incomplete (type II or III). In humans, IM is generally considered to be the precursor of gastric cancer, especially for intestinal type carcinomas. To date, no studies have investigated the clinical, endoscopic and histopathological findings of gastric IM in the dog and cat.

Aims

To evaluate prevalence and type of gastric IM, to describe its clinical and endoscopic characteristics; to investigate a possible association with carcinoma in dogs and cats with chronic gastritis.

Materials and Methods

Medical records of 170 dogs and 50 cats diagnosed with chronic gastritis or gastric carcinoma were reviewed. Criteria of inclusion were: histopathological evidence of gastric IM on either endoscopic or surgical biopsies, endoscopic records and a minimum follow-up of six months. Animals treated with immunosuppressive drugs in the last six months were excluded. Twenty-eight dogs (16.5%) and five cats (10%) fulfilled the inclusion criteria. Clinical aspects and long term outcome were also assessed.

Results

The mean age was 6,4 and 7,8 years in dogs and cats respectively, a male predisposition (60%) was observed in both species; no breed predisposition was found. Prevalent clinical signs were chronic vomiting (24 dogs and 5 cats) and anorexia (10 dogs and 3 cats). Endoscopic appearance was consistent with chronic gastritis or normal, whereas in 2 dogs the mucosa resembled a small bowel mucosa. In most cases (26 dogs and 5 cats) histopathology detected incomplete IM. Helicobacter organisms were present in 8 dogs and one cat. Gastric carcinoma was associated with IM in 4 dogs and one cat. Mean follow-up range was 19 and 12 months in dogs and cats respectively. Sixteen dogs and 2 cats did not show recurrence of clinical signs after pharmacologic and dietary management. Repeat biopsies in 2 dogs showed progression of IM towards carcinoma and complete regression respectively.

Discussion

These results suggest that IM may coexist with chronic gastritis and progress to gastric carcinoma in few cases. The potential role of IM in gastric carcinogenesis in small animals is unknown. Furthermore, the poor correlation between endoscopic and histological findings, together with lack of specific symptoms, support the usefulness of histological re-evaluation in patients with gastric IM.