SUMMARY
Helicobacter pylori represents one of the most common and medically prominentinfections worldwide. Infection with these bacteria has an association with histological gastritis,gastric atrophy, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma of thestomach in dogs and cats. Chronic infection of dogs with Helicobacter infection is characterized by aninfiltration of polymorphonuclear and mononuclear cells and frequently with hypertophy of limphoidfollicles in the gastric mucosa. The aim of this study was to identify the Helicobacter pylori infectionby immunohistochemical method from dogs with gastritis lesions. The most common types of specificgastritis were chronic gastritis characterized by an inflammatory infiltrate with lymphocytes,macrophages and plasma cells in the lamina propria of the gastric mucosa, atrophy of the gastricglands, fibrous tissue proliferation and hypertrophy of limphoid follicles in gastric mucosa.Immunohistochemical method identified the Helicobacter pylori infection on the surface layer ofgastric epithelium and lumen glands in five dogs.