PREVALENCE, ACQUISITION, AND TREATMENT OF DIDELPHOSTRONGYLUS-HAYESI (NEMATODA, METASTRONGYLOIDEA) INFECTION IN OPOSSUMS (DIDELPHIS-VIRGINIANA)

Several cases of didelphostrongylosis (lungworm infection) were diagno sed in opossums (Didelphis virginiana) at a wildlife rehabilitation ce nter in California. A study was initiated to determine the source and distribution of infection in resident and newly arriving opossums and the efficacy of fenbendazole in treating the infection. Fecal samples were collected before treatment and 1, 2, 3, 4, and 8 wk after the sta rt of a 14-day course of fenbendazole. The Baermann procedure was perf ormed for the detection of lungworm larvae. Lungworm infection was dia gnosed in 13 (65%) of 20 resident opossums and 10 (77%) of 13 newly ar rived opossums, for an overall pretreatment prevalence of 70%. Four un infected animals housed with infected animals did not become infected. These observations and others suggested that most infections were acq uired in the wild rather than in the rehabilitation center. Fourteen d ays of oral fenbendazole treatment at 50 mg/kg/day eliminated larval s hedding in the feces of 11 (73%) of 15 infected animals from which ind ividually identifiable fecal samples had been collected. Information f rom this study should be of use to those responsible for the care of c aptive marsupials.