EFFICACY OF FENBENDAZOLE IN THE TREATMENT OF EXPERIMENTAL GIARDIA INFECTION IN DOGS

Objective-To evaluate the efficacy of fenbendazole as a treatment for Giardia sp. Animals-10 male and 10 female commercial-source Beagles. P rocedure-The experiment was conducted in 2 replicates. Dogs considered free of Giardia infection on the basis of results of 3 consecutive ne gative fecal examinations were experimentally infected with approximat ely 1,000 Giardia cysts isolated from dog feces. After verification of infection, the dogs were allocated to 2 groups (treated and untreated ) and were housed in separate rooms. Treated dogs received 50 mg of fe nbendazole/kg of body weight, PO, daily, for 3 days. After treatment o n the third day, treated dogs were removed from their runs, shampooed, rinsed with disinfectant, and returned to disinfected runs. Fecal sam ples were collected from all dogs 12 times during the next 25 days. Re sults-Giardia cysts were found in the feces of every untreated dog dur ing all or part of the test period. Nine of 10 treated dogs did not ha ve Giardia cysts in any fecal sample examined; the other dog had a pos itive result on a single sample in the third week after treatment. Con clusion and Clinical Relevance-Fenbendazole, at the nematocidal label dosage, is an effective drug for treatment of Giardia infection in dog s.