A longitudinal study was performed on a Minnesota pygmy goat herd with a history of chronic weight loss, abortion and death. A variety of immunological responses over time were ascertained by serial fecal cultures, ELISA and interferon-gamma assays. For instance, five strongly ELISA positive and fecal culture negative goats later became ELISA-negative. Two of 5 culture-positive goats tested positive by the interferon-gamma assay for paratuberculosis using the USDA-licensed kit for use on cattle (IDEXX Laboratories, Inc.). This suggests that the monoclonal antibody against bovine interferon-gamma cross-reacts with goat interferon-gamma as suggested by Woods et al. Gross pathology included serous atrophy of fat, mineralization and caseation of lymph node granulomas. Intestinal wall thickening was not evident grossly. Acid-fast organisms were found in all goats with lesions at gross necropsy (in the ileum, jejunum, cecum and liver). M. paratuberculosis was also found in some animals in mesenteric, colic and mediastinal lymph nodes, as well as the colon and lung. Results from the culture of tissues also showed dissemination of the infection: organisms were recovered from mammary, kidney, uterine and splenic tissues as well as those noted via histopathology. Although limited by incomplete records, analysis suggests a strong association between the paratuberculosis test status of each goat and that of its dam. This evidence, coupled with finding a culture-positive fetus and isolation of the organism from the liver suggests the infection disseminates in the latter stages of the disease and may spread to offspring in utero and/or via colostrum or milk.