NEW improved flea and tick control topical formula with new active ingredientStarts killing flea and ticks within 15 minutesBio Spot Defense kills all flea life stages - eggs, larvae, and adultsKills all flea life stages, ticks, PLUS kills and repels mosquitoesFive weight ranges means flea and tick control that's right for your dogFor dogs over 6 months of ageDefend your dog from ALL flea life stages, ticks and mosquitoes. Bio Spot Defense with improved formulation provides fast-acting and long-lasting protection from fleas no matter what life stage they're in. Bio Spot Defense for Dogs starts killing fleas and ticks within 15 minutes and continues to kill adult fleas, flea larvae, flea eggs, and ticks for up to 21 days. Kills and repels mosquitoes (a major carrier of canine heartworm) for up to 28 days. Insect Growth Regulator (IGR) in Bio Spot Defense controls the development of flea larvae for up to two and a half months to break the flea life cycle and control flea re-infestation.Squeeze easy-to-apply liquid topical directly on your pet's skin each month for effective year-round use on indoor and outdoor dogs. Water-resistant formula keeps killing fleas and ticks in humid and wet conditions. Bio Spot Defense contains lanolin for coat conditioning and has a fresh clean scent.