CEREBROSPINAL LARVA MIGRANS DUE TO BAYLISASCARIS-PROCYONIS IN A GUINEA-PIG COLONY

Four guinea pigs from a colony of approximately 50 animals were examin ed for progressive neurologic disease of 5 days' duration. Signs of ne urologic dysfunction included cachexia, stupor, hyperexcitability, lat eral recumbency, and opisthotonos. Results of gross pathologic, microb iologic, and serologic examinations were unremarkable. Histologic exam ination of cerebral and cerebellar sections revealed multifocal malaci a and regions of eosinophilic granulomatous inflammation. Cross-sectio ns of nematode larvae, identified as Baylisascaris sp., most likely B. procyonis, the raccoon ascarid, were seen in the brain of some affect ed animals. An intact Baylisascaris larva was recovered from a symptom atic animal when cerebral tissue was processed by the Baermann extract ion technique, Results of further investigation indicated that wood sh avings used for the guineapigs had been contaminated by raccoon feces, some of which contained numerous B. procyonis eggs. The bedding sourc e for this colony was changed and, to date, no new cases of neurologic disease have been seen. This report emphasizes the potential insidiou s entrance of B. procyonis into well-managed laboratory animal facilit ies.