Follow-up studies by large intestinal biopsies and necropsy in dogs with clinical signs of large bowel disease.

The results of follow-up studies in 77 dogs with clinical signs of large bowel disease are presented. In 32 dogs colonic and/or rectal biopsy follow-up studies were done, combined with necropsy in seven dogs. In 45 dogs a follow-up necropsy only was done. The time between the first and the last series of biopsies varied from three to 729 days and between the first series of biopsies and necropsy from one to 980 days. Colitis found in 45 dogs in the initial biopsies was still present in 29 cases in the follow-up biopsy studies and/or at necropsy. Eleven cases showed hystiocytic ulcerative colitis. In general, adenoma, carcinoma and lymphosarcoma were confirmed in the follow-up examination, except for one adenoma, which appeared to be a carcinoma at necropsy. In cases in which the differential diagnosis was adenoma or carcinoma, the necropsy diagnosis was always carcinoma and in cases of a differential diagnosis of lymphosarcoma and/or colitis, lymphosarcoma was always diagnosed at necropsy. Several dogs without colonic changes in the initial biopsies had other gastric or small intestinal lesions at necropsy such as gastritis and enteritis of the small intestine, or tumors, in these areas.