The monkeys were kept as breeding pairs in cages of 1 X 1 X 2 in (1 X w X h) furnished with two branches and a nest box (40 X 30 X 30 cm), and under natural photoperiod conditions with approximately 13 hours of light each day, length varying with seasonality. The cages were kept in a building with wide wire mesh windows. The mean temperature throughout the year was 26ºC (24.1-28.1ºC) and the annual mean precipitation was 3,115 min (2,483-3,359 mm). The animals were fed twice a day with a biscuit (21% crude protein) prepared at the CRCP, ripe bananas, and water ad libitum.
From January 1987 to November 1990, 125 adult Saguinus mystax died at the CRCP, 76 from quarantine and 49 from the stable colony. Most of the monkeys were wild-caught in the Peruvian Amazon region and some were captive-born. Routine procedures at quarantine included oral treatment with the antinematode drug Thiabendazole (100 mg/k of body weight). Time in captivity varied from a few days for recently wild-caught S. mystax to up to ten years. Necropsies were done onall dead monkeys using established techniques [9]. Tissue samples of all major organs were taken from selected cases (n = 20) and fixed in 10% neutral buffered formalin. Sections were stained routinely with hematoxylin and eosin. When an infection was suspected, feces, exudates, or pus were collected in sterile containers and bacteriological analyses were performed according to standard procedures [18]. When skin lesions were visible, skin scrapings were investigated for parasites and fungi.
