FRONTLINE Tri-act Spot-on solution Dog 10-20Kg Fleas and ticks Horse flies Phlebotomists Mosquitoes 3 2ml pipettes Frontline Tri-Act spot-on solution is intended for medium-sized dogs weighing 10 to 20 kg. 3 in 1: removes, treats, prevents. Frontline Tri-Act is an anti-parasitic solution for the treatment and prevention of infestations by fleas, ticks, horseflies, sandflies and mosquitoes. Fleas are eliminated within 24 hours, preventing possible infestations in the 4 weeks following application. Frontline Tri-Act frees ticks within a maximum of 7 days, and those already present at the time of application will be eliminated within 48 hours. It also guarantees tick protection for over 4 weeks from the time of application. The product also repels mosquitoes for 4 weeks, sand flies for at least 3 weeks and horse flies for over 5 weeks after application.