These results confirm the high frequency of colitis reported in Callitrichidae in captivity [3,11,12,14, 16,19]. Colitis has also been observed frequently in Saguinus labiatus from our colony, but not in Aotus, Saimiri, Cebus, or Callicebus monkeys at the CRCP. However, in no case dysplasia suggestive of a preneoplastic lesion was found in colon of our tamarins compared with the related species Saguinus oedipus in which colon cancer is com monly found associated with chronic colitis.[4]. According to some authors [15], the first signs of wasting marmoset syndrome (WMS) in S. mystax were observed within two to three months after their arrival in the colony, and after four weeks WMS was registered to a greater or lesser extent in all the tamarins. At present, 'no causative agent could be identified. No known bacterial pathogens (Salmonella, Shigella, Clostridia, Yersinia) could be isolated [13] or detected during routine bacteriology [15]. Campylobacter has been isolated, but is difficult to evaluate because it is found in clinically healthy monkeys as well [10]. According to other authors [17], no connection was found between chronic colitis and enterobacterial common antigen in tamarins. Corona viruses have been identified, but it remains questionable whether these.viruses really played any etiological role or were simply secondary opportunists [2]. The frequency of colitis was not influenced by different types of diet [7], but still the diet given in captivity necessarily differs remarkably from the natural diets of these monkeys in the wild. Chronic colitis, if not the cause of wasting marmoset syndrome, is better associated with it than are other lesions [5]. According to a recent study [ 15], WMS occurred when the animals were fed on only a low-protein diet. Paramyxovirus has been reported as a cause of gastroenterocolitis in marmosets, but it is characterized by necrosis and sloughing of surface epithelium of stomach and colon with formation of syncytial cells containing intranuclear inclusions [8]. Diet change, caging, captive stress, and probably exposure to new patho gens, are all factors contributing to anorexia in S. mystax. However, changes in caging, larger well ventilated cages illuminated with natural light and located in a silent place, and diet change, biscuits blended with ripe bananas, and marmoset jelly 5041 (Purina Mills Inc., St. Louis, MO.),' appear to improve the ability of the tamarins to get used to their new environment with lower mortality at quarantine. No microorganism was found as the cause of acute lobular pneumonia. Apparently, sud den changes in environmental conditions affected weak predisposed monkeys. Diffuse liver cell vacu olation and lipofuscinosis were observed during aging or severe malnutrition and cachexia [6]. We agree with other authors that colitis is considered to be the most important life-threatening disease in tamarins in captivity. According to our findings, we hypothesize that colitis is probably a conse quence of a chronic exposure to a diet-related an tigen to which tamarins are allergic. Severity of lesions was clearly associated with time in captiv ity-the average time in captivity for those dying with colitis cystica profunda was 51 months ± stan dard deviation of 33 months. First signs of diarrhea in recently wild-caught S. mystax were observed usually between the first and second month of being in captivity. Hemorrhagic gastroenterocolitis ap pears to be more an acute, probably diet-related disease. Further studies must be concentrated on diet to establish the etiology of gastroenteric lesions observed so frequently in tamarin colonies.
