Virus in the intestinal tract during persistent FECV infection. Two cats inoculated with a 10−1 dilution of FECV UCD stock were euthanized 64 and 68 days later while still shedding virus. Intestines were sectioned into 5-cm (from stomach to appendix) and 1-cm segments (downstream of appendix) and the viral RNA in faecal content and intestinal tissue was determined for each segment by real-time RT-PCR. Section numbers refer to the following parts of the gut. For cat 146: 1–10, duodenum; 10–156, jejunum and ileum; 157–166, colon; 167–177, rectum. For cat 150: 1–10, duodenum; 10–160, jejunum and ileum; 160–177, colon; 178–184, rectum.