Helicobacter pylori (HP) is the causative agent of many gastrointestinal diseases. Horses, calves, pigs, rabbits, and chickens were evaluated for HP presence, and the pathogenetic effect on their gastric mucosa. The large-sized animals all resulted positive. No positive cases were observed in rabbits and chickens. Chronic inflammatory response to the infection with the development of acquired lymphoid tissue associated to the mucosa was revealed. The recognition of HP in animals living near the human habitat such as animals for slaughter and for technical zootechnic and alimentary use, before the witnessing of the transmission of this infection such as a zoonosis or an anthropozoonosis, can contribute to research on a common source for human and animals as reservoir. It is possible to consider that the intraspecies transmission of infection occurs by vomit, the mucus acting as a vector, while the interspecies one is due to the faecal contamination of the food chain.