Prevention and treatment of Encephalitozoon cuniculi infection in rabbits with fenbendazole

The efficacy of fenbendazole for preventing an experimental infection of En cephalitozoon cuniculi and for eliminating the spores from the central nerv ous system of naturally infected rabbits was investigated. Fenbendazole (20 mg/kg bodyweight daily) was administered from seven days before until two or 21 days after rabbits had been infected orally with ins spores of E cuni coli. Both regimens were effective in preventing the establishment of the p arasites, as demonstrated by negative parasitic-specific serology and by th e failure to isolate the parasite from brain tissue. In naturally infected, seropositive rabbits, parasites were successfully isolated from seven of n ine untreated animals, but not from the brain tissue of eight animals treat ed with fenbendazole-medicated pellets for four weeks.