Bravecto starts working very quickly after administration. For dogs, it begins killing fleas within 2 hours and achieves effective flea control in about 8 hours. It kills ticks within 12 to 48 hours. For cats, Bravecto eliminates fleas within about 12 hours and kills ticks within 48 hours. The active ingredient, fluralaner, targets the neurological system of fleas and ticks, leading to paralysis and death of these parasites. Bravecto also offers long- lasting protection, controlling flea and tick infestations for up to 12 weeks in dogs and several weeks in cats. This rapid onset of action provides fast relief for infested pets and helps prevent the spread of parasites and potential disease.