Objective: To evaluate efficacy of a combination of praziquantel, pyrantel pamoate, and febantel at 2 dosages for treating naturally acquired giardiasis in dogs.
Animals: 6 male and 9 female Beagles.
Procedure: Dogs were identified as naturally infected with Giardia sp, using the zinc sulfate concentration technique (ZSCT), and were allocated to 1 of 3 groups. Group-1 dogs were treated orally with a praziquantel (5.4 to 7 mg/kg of body weight), pyrantel pamoate (26.8 to 35.2 mg/kg), and febantel (26.8 to 35.2 mg/kg) combination, every 24 hours for 3 doses. Group-2 dogs were treated with the combination once. Group-3 dogs were nontreated controls. Four fecal samples were examined, using the ZSCT, from each dog of each group within 6 days of the last treatment. Dogs were considered to have giardiasis if 1 or more of the fecal samples had positive results for Giardia cysts. Dogs were examined daily for at least 10 days after the last treatment.
Results: Giardia cysts were not detected in the feces of any group-1 dog or in the feces of 2 of 5 group-2 dogs. Cysts were detected in the feces of 5 of 5 group-3 (nontreated control) dogs. Signs of toxicosis were not observed in any dog.
Conclusion and clinical relevance: The current labeled dose (for treatment of various nematodes and cestodes, but not Giardia sp) of the combination given orally once reduces cyst excretion in Giardia-infected dogs, and should be considered for treatment of dogs shedding Giardia cysts, whether or not they have clinical signs of infection.