Apply Centragard to your cat exactly as directed by your veterinarian. If you don't understand the directions, ask your pharmacist or veterinarian to explain them to you. Centragard is dosed at a minimum of 0.055 ml/lb, which delivers a dose of 0.23 mg/lb eprinomectin and 4.55 mg/lb praziquantel. Administer the entire contents of the applicator topically once a month.