Holmberg Ca

Nontuberculous Mycobacterial Disease In Rhesus Monkeys

In a colony of rhesus monkeys (Macaca mulatta), 42 cases of nontuberculous mycobacterial-related disease were identified from 1970 to 1978. The disease affected young and old colony-born and wild-caught monkeys of both sexes. Serotypes 1, 2, 4, 8, and 18 of the Mycobacterium avium-intracellulare group were isolated from different monkeys. The lesions were primarily intestinal in 36 monkeys. Lesions of the large intestine, small intestine, and mesenteric lymph nodes were characterized by diffuse accumulations of large macrophages containing many acid-fast bacteria. Acid-fast bacteria could not be identified histologically in four monkeys with typical histories of diarrhea and weight loss, positive skin reactions to the tuberculin test with M. avium tuberculin, and isolation of the organism from tissues on one or more occasions. Two monkeys had histologically positive lesions limited to the lungs, although chronic colitis of undetermined cause was present.

A Pathologic and Toxicologic Evaluation of Veal Calves Fed Large Amounts of Zinc

Tissues were examined from 26 male Holstein veal calves given large amounts of dietary zinc. All calves had been fed 706 μg zinc/g of milk replacer for 28 days before the first death occurred. Calves died naturally (14, group A) or were euthanatized (12, group B) after 23 days of feeding a lower concentration of zinc (150 μg/g). Average amounts of zinc in liver (wet weight) were 345.72 μg/g (group A) and 344.84 μg/g (group B). Mean kidney zinc concentrations were 219.0 μg/g (group A) and 252.38 μg/g (group B). Tissue manganese, copper, and iron levels were normal. Changes at necropsy included pneumonia, fluid digesta, and petechiae and infarcts in liver, kidney, and heart (as a result of bacterial infections). Histological changes that were directly attributed to dietary zinc intake were: marked atrophy and necrosis of pancreatic acinar tissue (group A); multifocal fibrosis of pancreatic acini (group B); multifocal renal cortical fibrosis with necrosis in convoluted tubules and loops of Henle, and with intratubular mineralization (groups A and B). Hepatic midzonal mineralization and fibrosis of the adrenal zona glomerulosa were seen in group B calves.

Malignant Lymphoma in a Colony of Macaca arctoides

Malignant lymphoma occurred in six Macaca arctoides from a colony of 83 animals during a 30-month period. The cells of two neoplasms had T cell markers. Concurrent disease processes included atypical mycobacterial disease in four macaques and progressive multifocal leukoencephalopathy in one.

Clinicopathological Studies of Gastrointestinal Disease in Macaques

Evaluation of mortality during a two-year period at a primate colony indicated that 34% of nonexperimental deaths in macaques one year of age and older were due to gastrointestinal disease. Of deaths related to gastrointestinal disease, 12% had acute gastric dilatation, 18% had shigellosis, 12% had nontuberculous mycobacterial disease, and 58% were of undetermined cause. Histologic evaluation of the alimentary tract indicated that the large intestine was the most common site of anatomical change in monkeys that had diarrhea at the time of death. Monkeys that had a single terminal episode of diarrhea had less gastric inflammatory lesions than those that had multiple episodes of diarrhea in the last year of life.