Johnson's 4fleas Spot-on for Small Dogs and Puppies 4-10kg is a fast acting spot-on that kills fleas on contact on your dog and surrounding area. For the prevention and treatment of flea infestations and for the treatment of biting lice. This treatment provides up to 2 months protection and contains 2 vials, each vial giving up to 4 weeks protection. One treatment prevents further flea infestation for four weeks. Fast Acting Spot-On, kills fleas on contact (on your pet) and the surrounding area for up to 2 months protection. For pets over 8 weeks of age. Contains 2 vials, each vial giving up to 4 weeks protection. Johnson's 4Fleas Spot-On Dual Action for Small Dogs flea treatment for small dogs of 4kg up to less than 10kg Kills fleas, kills flea larvae.