Vet recommended flea treatment and prevention for dogs at weighing over 55 lbs., at least 7 weeks of age Kills adult fleas, flea larvae and flea eggs for total flea prevention and treatment Same-day effectiveness, kills fleas within 12 hours of application and keeps working for 30 days Easy-to-apply topical treatment, no prescription needed Fragrance-free formula, waterproof after 24 hours