['Helicobacter pylori may have multiple routes of transmission. It is unclear, however, whether the agent is also zoonotic and therefore transmitted from an animal reservoir.', 'The aim of this population-based study was to assess the relationship of exposure to pets and H. pylori infection among children in a population-based sample in Ulm, a city in the South of Germany.', 'All children of German nationality who were to attend first grade in the school year 1996/1997 were included in the study. The 13C-urea breath test was used to determine active infection status. In addition the parents filled out a questionnaire to provide information about pets in the household as well as living conditions and socioeconomic factors of the family.', 'Of 927 eligible preschool children 685 (74%) participated in the study. Prevalence of infection was 6.3%. Infection with H. pylori was not positively associated with contact with pets in general (p = 0.720) or to a specific kind of animal in bivariate and multivariable analyses as evaluated by means of logistic regression.'] Are pets a risk factor for Helicobacter pylori infection in young children : results of a population-based study in Southern Germany?