Advantage for Large Dogs is a topical solution for large size dogs that weigh between 10-25kg. This spot-on formula for dogs is highly effective in killing adult fleas and larvae on dogs and their surroundings. A single dose of Advantage Red pack kills re-infesting fleas within 1 hour and flea larvae in your dog's surroundings within 20 minutes of contact with the active ingredient. This quick action formula destroys 99% of fleas within a few hours. It also destroys chewing lice in 7 days post-application. Advantage for Dogs 10-25kg pack also reduces the incidence of flea allergy dermatitis. It is a water-resistant treatment that works for 30 days even if the dog goes for a bath or swimming.