How long do flea drops work for cats? - briefly
Flea spot‑on products typically provide protection for roughly one month, with most brands guaranteeing efficacy for 30 days after application. A few newer formulations extend coverage to 8–12 weeks, depending on the active ingredient.
How long do flea drops work for cats? - in detail
Flea spot‑on products for felines are designed to release active ingredients that kill and repel parasites for a defined period after a single application. The typical efficacy window ranges from four to six weeks, depending on the formulation and the active compound used.
The most common active ingredients and their reported durations are:
- Imidacloprid – maintains killing activity for up to 30 days.
- Fipronil – provides protection for 30–35 days.
- Selamectin – effective for 30 days against fleas and additional parasites.
- Nitenpyram – kills existing fleas within hours, but does not offer lasting protection; a monthly re‑application is required for continued control.
- Spinosad – delivers rapid kill and residual activity for 30 days.
Factors that can shorten or extend the protection period include:
- Cat’s weight – under‑dosing or overdosing relative to body mass reduces effectiveness.
- Bathing or swimming – washing within 24–48 hours after application may wash away the medication; regular bathing thereafter does not usually affect efficacy.
- Seasonal flea pressure – high environmental infestations may increase the chance of re‑infestation, requiring supplemental control measures.
- Health status – skin conditions or excessive oil production can interfere with drug absorption.
For optimal results, apply the product directly to the cat’s skin at the base of the neck, ensuring the entire dose contacts the skin. Re‑apply according to the manufacturer’s schedule, typically every four weeks, and monitor the cat for any adverse reactions. If flea activity persists beyond the expected period, consider environmental treatment and consult a veterinarian for alternative or adjunctive therapies.