ample, stress due to severe dominance relationships between animals). A familiar technician can calm the animals during treatment and can administer many medications topically or orally in food without the need for handling the animals. The feeding of high-protein snacks each morning and each afternoon not only increases the protein content of the diet, but allows animal care staff to monitor the animals more often.
Marmosets and tamarins are susceptible to a number of human diseases, including measles, mumps, and cold sores caused by Herpesvirus simplex . These disease agents can cause potentially fatal infections. Herpesvirus saimiri is carried by squirrel monkeys; although it is not associated with any disease in these monkeys, it causes leukemia or malignant lymphoma in callitrichids, so marmosets and tamarins should not be housed in a room that contains squirrel monkeys (Adams and others 1995). Callitrichids and cebids should not be housed together, because of risk of disease transmission (Bennett and others 1995).
A "wasting syndrome" has been described in many species of captive callitrichids that includes such symptoms as weight loss, anemia, colitis, and extensive diarrhea; but there appear to be great differences in susceptibility between colonies of the same species and no clear agreement about the etiology. Suggested etiologies have involved nutrition, infectious agents, and environmental social stress; in cotton-top tamarins, spontaneous adenocarcinoma of the colon has been described. Some colony managers have found that the condition of some animals experiencing apparent social stress can be improved by moving the affected animals to a new social environment (Knapka and others 1995; Morin 1983).