Global Medical Manager VIRBAC CARROS, Provence-Alpes-Cote d'Azur, France
Background: Giardia duodenalis is a commonly found gastrointestinal protozoan parasite in dogs. Metronidazole is a nitroimidazole antimicrobial with antiprotozoal actions.
Objectives: This clinical field study assessed the efficacy of a flavored oral suspension containing 125mg/mL of metronidazole intended to treat Giardia duodenalis infection in dogs. Animals: Client-owned dogs (n=129), naturally infected with Giardia duodenalis from European countries (Germany, Hungary, Portugal), were enrolled in the study, randomized to one of two groups and included in the effectiveness analysis. In the metronidazole treated-group, eighty-nine (89) dogs received a flavored oral suspension containing 125mg/mL of metronidazole. In the control-group, forty (40) dogs received a vehicle flavored oral suspension (equivalent to the final formulation of the product minus metronidazole). All dogs received 0.2 mL/kg twice daily for 5 consecutive days (i.e. 25mg/kg of metronidazole twice daily).
Methods: The study was a double-masked vehicle-controlled randomized and blocked multicenter trial. Fecal samples were collected pre-treatment on Study Day -3, -2 and -1 and post-treatment on Study Day +5, +6 and +7. A Giardia cysts count was calculated as Giardia cysts per gram of feces using Immuno-Fluorescence Antibody Test.
Results: Metronidazole was significantly more efficacious than the vehicle reducing the baseline cysts counts 220 times more effectively (p < 0.001). Percentage baseline cyst count reduction, calculated for the metronidazole-treated group, showed a metronidazole effectiveness of 99.92% (Figure 1).
Conclusion: The results demonstrated that the flavored oral suspension containing 125mg/mL of metronidazole dosed at 0.2mL/kg twice daily for 5 days is efficacious for treating Giardia duodenalis in naturally infected dogs.
