More than 150 adult cattle from seven dairy herds were followed to slaughter to collect tissues from the pulmonary, mandibular, retropharyngeal, hepatic, supramammary, ileocecal and mesenteric lymph nodes and from multiple sites along the jejunum, colon and ileum. Approximately 30% of the cattle that were negative on repeated fecal cultures had culture positive tissues obtained at slaughter. Fifteen (18%) of the 82 cattle with positive fecal cultures had culture negative tissues. Eight animals with negative tissues each had a single positive fecal culture with one colony on one tube. M. paratuberculosis was isolated from many tissues throughout the bodies of cattle with heavy bacterial loads (more than 10 colonies per fecal culture tube) and clinical signs of Johne's disease. These results suggests that disseminated infection occurs frequently in animals with Johne's disease.