Vectra 3D Gold for Extra Small Dogs 5 - 10 Pounds (3 Doses) Can be used on Dogs and puppies 8 weeks of age and older. Fast acting. Reduced flea feeding in 5 minutes. kills fleas in 6 hours. Kills on contact. Parasites do not have to bite to die. Broad spectrum protection. Quick drying and non-greasy formula. Convenient topical treatment with patented applicator. Long Lasting, quick drying, convenient topical treatment with patented applicator. Remains effective after bathing or swimming. Kills fleas that may cause flea allergy dermatitis(FAD), anemiacause, may transmit disease, including bartonellosis, tapeworm and tularemia. Each monthly dose controls development of all flea stages; Prevents, controls and stops flea infestation and prevents re-infestation.