Follow‐up Studies by Peroral Small Intestinal Biopsies and Necropsy in Dogs with Chronic Diarrhea

Summary The results of follow-up studies in 82 dogs with clinical signs of chronic diarrhea are presented. Follow-up studies were performed by small intestinal biopsies only in 19 dogs, combined with necropsy in six dogs and follow-up necropsy only in 57 dogs. The times between the first and the last series of biopsies varied from 18 to 561 days, and from one to 656 days between the first series of biopsies and necropsy. From the 11 dogs with villous atrophy in the first series of biopsies, three also showed villous atrophy in the following biopsies or at necropsy, two had enteritis, one intestinal lymphangiectasia, one lymphosarcoma and four had no small intestinal lesions. Villous atrophy and enteritis found in 20 dogs in the initial biopsies were still present in 12 dogs in the following biopsies, in one only the villous atrophy remained in the following biopsies, in four lymphosarcoma was diagnosed, in one a colitis and in two changes outside the gastrointestinal tract were found at necropsy. In six of the seven dogs with enteritis in the initial biopsies this was diagnosed again, once with VA; in the seventh dog a hypertrophic gastritis was found. In five of the eight dogs with a diagnosis of lymphosarcoma in the initial biopsies a lymphosarcoma was found at necropsy, two had a villous atrophy with enteritis and in one only a differential diagnosis lymphosarcoma and/or enteritis could be made. In two of the three dogs with the differential diagnosis lymphosarcoma and/or enteritis this diagnosis was also made at necropsy, while one dog only had enteritis at necropsy. The biopsy diagnosis carcinoma in one dog was confirmed at necropsy. In 31 dogs the first series of small intestinal biopsies showed no pathological changes, but in four of them villous atrophy was diagnosed in necropsy follow-up studies (one of them had no diagnosis in earlier follow-up biopsies), in four other dogs villous atrophy with enteritis, in seven dogs enteritis, in one dog lymphosarcoma, in five dogs gastric lesions and in four dogs extragastrointestinal lesions were found. In five dogs the follow-up studies by biopsies did not show lesions and in one the follow-up biopsies were not suitable for examination. Another dog with initial biopsies not suitable for examination showed colitis at necropsy.