How many days does Simparica for ticks work in dogs? - briefly
A single oral dose of Simparica protects a dog from ticks for approximately 35 days (about five weeks).
How many days does Simparica for ticks work in dogs? - in detail
Simparica (sarolaner) is administered as a chewable tablet that provides systemic protection against a broad spectrum of tick species. After a single dose, the compound begins to act within a few hours, achieving 90 % kill of attached ticks in approximately 8 hours and reaching near‑complete elimination (≥ 95 %) by 12 hours. The protective effect persists for the entire dosing interval, which is defined as one month. Clinical trials have demonstrated that efficacy remains above 90 % for at least 30 days, with some data indicating activity lasting up to 35 days under optimal conditions.
Key factors influencing the duration of protection:
- Weight‑based dosing – the recommended amount (2 mg kg) ensures plasma concentrations sufficient to maintain tick‑killing activity throughout the interval.
- Administration timing – dosing on the same calendar day each month prevents gaps in coverage.
- Species variation – most common tick species (e.g., Ixodes scapularis, Rhipicephalus sanguineus, Amblyomma americanum) are killed within the stated timeframe; some less susceptible species may require strict adherence to the monthly schedule.
- Drug resistance – emerging resistance can reduce efficacy, reinforcing the need for regular veterinary monitoring.
For continuous tick control, the product should be given every 30 days without interruption. If a dose is missed, administer it as soon as possible and resume the regular monthly schedule; do not double‑dose to compensate. Veterinary guidance may be required for dogs with health conditions that affect drug metabolism, as these can alter the effective protection period.