How long does Simparica work against ticks? - briefly
A single oral dose of Simparica protects dogs from tick infestations for up to 35 days. The effect persists throughout the month after administration.
How long does Simparica work against ticks? - in detail
Simparica, containing the active ingredient sarolaner, is administered as a chewable tablet for dogs. After a single oral dose, the product provides continuous tick control for a full month. Pharmacokinetic studies show that therapeutic blood concentrations are maintained for at least 35 days, which is the interval recommended for re‑dosing.
The onset of activity occurs within 3 hours of ingestion, and efficacy against common tick species—including Ixodes scapularis, Rhipicephalus sanguineus, Dermacentor variabilis, and Amblyomma americanum—remains consistent throughout the dosing interval. The duration of protection is not significantly altered by the dog’s weight, age, or breed when the label‑specified dose (2 mg kg⁻¹) is used.
Factors that can influence the effective period:
- Missed dose: A delay beyond 35 days reduces protection; re‑treatment should occur as soon as possible.
- Concurrent medications: Certain drugs that induce hepatic enzymes may lower sarolaner plasma levels, potentially shortening efficacy.
- Extreme environmental exposure: Very high tick pressure may increase the chance of breakthrough infestations, though clinical trials report >95 % kill rate throughout the month.
If a dog is at high risk for tick‑borne diseases, a veterinarian may recommend maintaining the monthly schedule without interruption. In cases of accidental overdose, the drug’s half‑life (approximately 12 days) ensures that excess amounts are eliminated without extending protective coverage beyond the standard period.
In practice, the label‑approved monthly administration guarantees that a dog remains protected against ticks for the entire month between doses, provided the product is given with food and the recommended dosage is followed.