Dogs and cats are often infected with large spiral organisms, and some are classified as Helicobacter heilmannii, the pathogen associated with gastritis in people. H. heilmannii type 1 is the prominent subtype in humans and is believed to be acquired by zoonotic transmission from dogs. Cats and pigs are commonly infected with H. heilmannii-like organisms.

This study used techniques to examine genetic similarities and differences between H. heilmannii DNA obtained from 45 cats (American and German) and 10 dogs (Danish). There were no obvious differences in the DNA sequences from dogs and cats of different countries. These animals were primarily colonized with H. heilmannii types 2 and 4. Thus, the zoonotic risk is probably low because humans are infected by H. heilmannii type 1.

COMMENTARY: Infection with Helicobacter pylori is now well-established as the major cause of gastric ulcers in people. Infection with Helicobacter heilmannii has also been incriminated as a cause of gastric disease, particularly of MALT lymphoma, in people. This organism has also been incriminated as a cause of gastric ulcers in pigs. Because it is also found in the stomach of many dogs and cats, it has been postulated that it may be transmitted from these species to their owners. The results of this study by a team of investigators in Europe and the U.S. show that this is unlikely, as dogs and cats are infected by different subtypes of H.heilmannii than are people. It is to be hoped that this is one more disease that physicians will not now be able to blame on the family pet!

Evaluation of "Helicobacter heilmannii" subtypes in the gastric mucosa of cats and dogs by ureB and 16S rRNA sequencing and fluorescence in situ hybridisation. Priestnall SL, Wiinberg B, Spehr A, et al. BSAVA CONGRESS SCIENTIFIC PROCEEDINGS, 2003, 546.