How long does Stronghold work against ticks? - briefly
Stronghold maintains tick control for approximately four weeks after each application. The protective effect ceases once the monthly dosing interval is exceeded.
How long does Stronghold work against ticks? - in detail
Stronghold, containing the active ingredient selamectin, provides systemic protection against a broad range of ticks. After a single dose applied to the skin, the drug is absorbed and distributed through the bloodstream, reaching concentrations sufficient to kill attached ticks within 24 hours. The protective effect persists for a full month, after which the concentration falls below the therapeutic threshold and re‑application is required.
Key points regarding the duration of efficacy:
- Onset of action: Tick mortality begins within 12–24 hours after exposure.
- Sustained activity: Selamectin maintains lethal levels for at least 30 days, covering the typical monthly dosing interval.
- Species variation: Efficacy has been demonstrated against Ixodes ricinus, Dermacentor variabilis, Rhipicephalus sanguineus, and Amblyomma americanum; some species may show slightly reduced susceptibility, but the overall month‑long protection remains consistent.
- Influencing factors: Age, body condition, and concurrent illnesses can modestly affect drug distribution, but standard dosing (1 mg/kg) accounts for typical variations in healthy dogs.
- Re‑application schedule: To ensure continuous tick control, repeat the topical treatment every 30 days without deviation.
Laboratory and field studies confirm that a single monthly application eliminates newly attached ticks before they can transmit pathogens, provided the product is used according to label instructions.