How long does Simparica work against ticks on dogs? - briefly
A single oral dose of Simparica protects dogs from tick infestations for approximately 35 days. The effect lasts until the next monthly administration.
How long does Simparica work against ticks on dogs? - in detail
Simparica is an oral chewable tablet containing sarolaner. After a single administration, the active ingredient begins to kill ticks within a few hours. Laboratory studies show that 90 % of Ixodes scapularis, Dermacentor variabilis and Rhipicephalus sanguineus are eliminated within 8 hours of dosing. Field trials confirm that a single dose maintains effective tick control for at least 35 days, the interval specified on the product label. Some investigations report residual activity up to 42 days, but consistent protection is achieved only when the medication is given every month.
Key points about the duration of action:
- Onset: Tick kill observed as early as 3 hours for certain species; 8 hours for most common infestations.
- Peak efficacy: Maintained throughout the fourth week after administration.
- Label claim: One chewable tablet provides protection for a full 35‑day period.
- Re‑dosing schedule: Monthly administration required to prevent gaps in coverage.
- Factors influencing efficacy: Proper dosing based on body weight, adherence to the monthly schedule, and the dog’s overall health.
The product’s safety profile supports monthly use in dogs weighing 2.8 kg (6 lb) or more. For continuous tick prevention, owners should administer Simparica on the same calendar day each month, adjusting the dose according to the dog’s current weight. Failure to re‑dose on schedule may allow tick re‑infestation after the 35‑day window expires.