What kills fleas on animals? - briefly
Topical insecticides with active ingredients such as fipronil, imidacloprid, or selamectin kill fleas on pets within hours. Oral agents like nitenpyram or spinosad also provide rapid eradication.
What kills fleas on animals? - in detail
Fleas on companion animals can be eradicated through chemical, biological, and environmental interventions.
Topical insecticides applied directly to the skin provide rapid knock‑down. Products containing fipronil, imidacloprid, selamectin, or permethrin diffuse across the coat, reaching parasites on contact. These agents disrupt the nervous system of the insects, leading to paralysis and death within minutes to hours.
Oral systemic medications circulate in the bloodstream, exposing feeding fleas to lethal doses. Afoxolaner, fluralaner, and sarolaner belong to the isoxazoline class; they block GABA‑gated chloride channels, causing uncontrolled neural firing and fatal convulsions. Oral products typically offer month‑long protection after a single dose.
Oral and injectable ivermectin, though primarily a nematocide, also exhibits activity against adult fleas, especially when combined with milbemycin.
Environmental control is essential because adult fleas lay eggs that develop into larvae and pupae in the surroundings. Vacuuming carpets, washing bedding at ≥60 °C, and applying insect growth regulators (IGRs) such as methoprene or pyriproxyfen interrupt the life cycle by preventing egg hatch and larval development.
Fumigant sprays and foggers containing pyrethrins or synthetic pyrethroids can decontaminate indoor spaces, but they must be used according to label directions to avoid toxicity to animals and humans.
In severe infestations, a combined regimen—topical or oral adulticide, IGR treatment of the environment, and rigorous cleaning—delivers the highest efficacy. Regular re‑application according to product intervals maintains a flea‑free status and prevents re‑infestation.