Gongylonema macrogubernaculum in captive African squirrels (Funisciurus substriatus and Xerus erythropus) and lion-tailed macaques (Macaca silenus)

Necropsies performed between 1989 and 1995 on 15 African rope squirrels (Funisciurus substriatus) and 20 African ground squirrels (Xerus erythropus) from the Baltimore Zoo revealed 13 cases of gongylonemiasis. Nem atodes were embedded in the epithelium of the esophagus, pharynx, buccal mucosa, and tongue, resulting in varying degrees of esophagitis, pharyngitis, stomatitis, and glossitis, respectively. Routine fecal examinations were negative, and the nematodes appeared to be unaffected by repeated treatments with ivermectin. Most of the affected animals had shown clinical signs of dyspnea and/or inanition and emaciation. Suppurative rhinitis was also a frequent finding at necropsy and was associated with the presence of the nematodes in eight animals. Dissection of whole nematodes from formalin-fixed specimens revealed morphologic features consistent with Gongylonema macrogubernaculum, a species previously only reported in nonhuman primates. The squirrels were housed in the same building with numerous primate species, and a review of pathology records revealed esophageal gongylonemiasis in three lion-tailed macaques (Macaca silenus), lingual gongylonemiasis in a spotnose monkey (Cercopithecus buettikoferi), and buccal gongylonemiasis in a brown-headed tamarin (Saguinus fuscicollis). Examination of whole nematodes dissected from one of the lion-tailed macaques also demonstrated the unique morphology of G. macro gubernaculum. Nematodes belonging to the species Gongylonema are acquired by ingestion of the intermediate host, the cockroach. This is the first report of G. macro gubernaculum in a nonprimate species and suggests that captive African squirrels can serve as reservoir hosts for this parasite in a zoo environment.