Canine gastritis associated with Helicobacter felis.

: Naturally occurring gastritis associated with Helicobacter felis was detected in two dogs. Histologically, chronic changes characterized by lymphofollicular aggregation were observed. Ultrastructurally, organisms located on the mucosal surface, within gastric pits and glandular epithelial cells. H. felis was isolated and urease activity was detected in all areas of the stomachs.