Causes of mortality in Saguinus mystax from January 1987 to November 1990 are summarized in Tables I and II. At quarantine, gastroenteric lesions (40.7%) and anorexia leading to hypoglycemia and cachexia (30.2%) were the most common causes of death. Less frequently, pneumonia (10.5%) and peritonitis (10.5%) affected recently wild-caught moustached tamarins. In monkeys from the colony with at least six months in captivity, gastroenteric lesions (51 %) were the most common findings, followed by peritonitis (14.2%), fatty liver change (6.1%), pneumonia (4.0%), and intussusception (4.0%). No sex differences were observed on frequency of diseases and mortality.
Table I. Necropsy findings in recently wild-caught Saguinus mystax from quarantine (1987-1990), CRCP, Iquitos, Peru.
| Diagnosis |
|
Females
|
Males
|
|
Total %
|
(No.)
|
(No.)
|
|
| Acute catarrhal enteritis/colitis |
22.3
|
11
|
6
|
| Parasitic enteritis |
11.8
|
4
|
5
|
| Hemorrhagic gastroenterocolitis |
6.5
|
2
|
3
|
| Hypoglycemia/cachexia |
30.2
|
14
|
9
|
| Lobular pneumonia |
10.5
|
4
|
4
|
| Purulent peritonitis |
6.5
|
-
|
1
|
| Parasitic peritonitis |
3.9
|
2
|
1
|
| Intussusception |
1.3
|
1
|
-
|
| Orchitis |
1.3
|
-
|
1
|
| Purulent nephritis |
1.3
|
1
|
-
|
| Sarcoptic mange |
1.3
|
-
|
1
|
| Not determined |
2.6
|
1
|
1
|
| Totals |
100
|
41
|
35
|
Gastroenteric lesions
In monkeys from quarantine, acute catarrhal enteritis/colitis was the most common finding (22.3%). Histologically, slight atrophy of intestinal villi was detected in some cases, and minimal proliferation of mature colon glands in the submucosa, with some diffuse mixed cellular infiltration in the sub mucosa and lamina propria in others. No neoplastic changes, dysplasia, or chronicity was observed in the colon of the tamarins. Attempts to isolate en teropathogenic bacteria were unsuccessful. A survey for Campylobacter revealed that at least 22.2% of recently wild-caught S. mystax carry Campylo bacter coli with no signs of diarrhea or weight loss [10]. Treatment with antibacterial drugs were unsuccessful. In some cases diet change (Marmoset Jelly 5041, Purina Mills Inc., St. Louis, MO) stopped diarrhea and improved the animals' health.
Parasitic enteritis caused by the acanthocephalan Prosthenorchis elegans was another important cause of mortality (11.8%). Five monkeys died from acute hemorrhagic gastroenterocolitis. Attempts to isolate enteropathogenic bacteria were also unsuccessful. Gastroenteric lesions in monkeys from the colony were similar, but chronicity was the main finding. Catarrhal enteritis/chronic colitis were the most frequent findings diagnosed grossly. Histologically, atrophy of the intestinal villi and colitis cystica profunda, characterized by the presence of mucusfilled cysts in the colon mucosa, submucosa, and muscularis propria, frequently lined by demonstrable epithelium, were observed. Additionally, four cases of terminal ileitis were observed in adult monkeys with at least five years in the colony. Parasitic enteritis was,also a common finding, but in this case the cestode Hymenolepis sp. was found in addition to the acanthocephalan Prosthenorchis elegans. In some cases, P. elegans infection in captivity was observed due to the presence of cockroaches. Apparently, the cockroach is also an intermediate host or mechanical vector for Hymenolepis. Three monkeys died from acute hemorrhagic gastroenterocolitis, but no enteropathogenic bacteria was isolated.
Table II. Necropsy findings in Saguinus mystax from colony (1987-1990), CRCP, Iquitos, Perú.
| Diagnosis |
|
Females
|
Males
|
|
Total %
|
(No.)
|
(No.)
|
|
| Catarrhal enteritis/chronic colitis |
30.6
|
9
|
6
|
| Parasitic enteritis |
14.2
|
2
|
5
|
| Hemorrhagic gastroenterocolitis |
6.1
|
1
|
2
|
| Purulent peritonitis |
8.1
|
3
|
1
|
| Purulent peritonitis and pyothorax |
4
|
1
|
1
|
| Parasitic peritonitis |
2
|
1
|
-
|
| Fatty liver change |
6.1
|
2
|
1
|
| Lobular pneumonia |
4
|
1
|
1
|
| Intussusception |
4
|
2
|
-
|
| Lung abcess |
2
|
-
|
1
|
| Hepatic abcess |
2
|
-
|
1
|
| Hypoglycemia/cachexia |
2
|
1
|
-
|
| Metritis |
2
|
1
|
-
|
| Forelimb paralysis |
2
|
1
|
-
|
| Cardiac insufficiency |
2
|
-
|
1
|
| Aged |
2
|
-
|
1
|
| Not determined |
6.1
|
-
|
3
|
| Totals |
100
|
25
|
24
|
Hypoglycemia/Cachexia
This condition, characterized by severe weight loss, muscle atrophy, alopecia, and dehydration with no signs of diarrhea, was observed mostly in monkeys from quarantine.,Anorexia was the main cause, apparently due to disability to adjust to captive conditions. Pneumonia The main cause of purulent peritonitis observed at quarantine (10.5%) and less frequently in the colony (4%). Bacterial cultures revealed in some cases enterobacteria as E. coli and Proteus mirabilis, which we assume were postmortem contaminants. Histologically, severe congestion and thickened alveolar septae with macrophages in the alveolar spaces was the primary observation.
Purulent peritonitis
The main cause of purulent peritonitis observed at quarantine and colony was the enterobacteria Klebsiella pneumoniae. Less frequently, parasitic peritonitis caused by rupture of the intestinal wall by the acanthocephalan Prosthenorchis elegans was observed. K. pneumoniae has been also isolated from a lung abscess and a hepatic abscess in monkeys from the colony. Due to the acute course of the disease, antemortem diagnosis was often not made.
Liver pathology
Three cases of yellowish livers in monkeys from the colony and diagnosed grossly as fatty liver change revealed at histologic examination extensive diffuse liver cell vacuolation along with severe lipofuscinosis.
Intussusception
Less frequently, small intestine intussusception was observed producing necrosis from the affected region. The pathology was associated with a persistent intestinal parasitism with protozoa in one case and Filariopsis barretoi larvae in another.
Other findings
Pentastoma larvae (Porocephalus sp.) were occasionally found in different organs with no signs of inflammatory reaction from the host. Lung nematodes (Filariopsis barretoi) were another common finding in wildcaught monkeys causing no pathologic changes. Filariae (Dipetalonema sp.) were observed frequently in peritoneal cavity of wild caught monkeys and, in a lesser degree, hepatic trematodes (Athesmia heterolecithoides). Other lesions not detected grossly were observed during histological examination. Pancreatic islet atrophy, lymphoid hyperplasia in the lamina propria, and mesenteric lymph nodes, not always detected grossly, were observed apparently associated with colitis cystica profunda. Myocardial fibrosis was an occasional finding in tamarins from the colony. Two cases of suppurative meningoencephalitis were detected in monkeys from the colony. One case of systemic mycosis was observed in an adult female from quarantine. Slight focal mononuclear cellular infiltration was occasionally found in kid neys and liver.
