When do fleas die after using Selafort? - briefly
Fleas generally die within 24 hours of a Selafort application, with any newly hatched insects eliminated by the next 48 hours. The product’s residual action continues to prevent re‑infestation for several weeks.
When do fleas die after using Selafort? - in detail
Selafort contains the insecticide fipronil, which interferes with the nervous system of fleas. After a single topical dose, the chemical spreads across the skin and enters the bloodstream, reaching parasites that feed on the host.
- Initial contact: Fleas that begin feeding within the first 4‑6 hours are exposed to lethal concentrations of the product.
- Rapid mortality: Most adult fleas die between 8 and 12 hours after exposure, as the neurotoxic effect disrupts GABA‑gated chloride channels.
- Complete eradication: By 24 hours, the majority of the adult population on the treated animal is eliminated; residual activity continues to kill newly emerged fleas for up to 30 days.
- Egg and larva control: The systemic action prevents surviving adults from reproducing, reducing egg viability and interrupting the life cycle.
Factors influencing the exact timing include the animal’s weight (dose is calibrated per kilogram), the health of the skin (intact cuticle improves absorption), and ambient temperature (higher temperatures accelerate metabolism). In cases of severe infestation, a secondary treatment may be recommended after 2 weeks to address any surviving stages.
Overall, the product begins killing fleas within hours, achieves near‑total adult mortality by the end of the first day, and maintains efficacy for a month, effectively breaking the flea life cycle.