Helicobacter heilmannii: A bacteria that infects most cats, dogs and pigs and, in them, causes stomach inflammation (gastritis). H. heilmannii is not usually transmitted from animals to people. But people who have been infected by H. heilmannii are known to have developed duodenal and gastric ulcers. Antibiotics can cure H. heilmannii infections.
H. heilmannii and its better-known relative H. pylori are spiral bacteria that can colonize the stomach, cause chronic gastritis, and create duodenal ulcers and, to a lesser extent, gastric ulcers. H. pylori is now recognized as a risk factor for gastric adenocarcinoma and lymphoma.