How many days does Simparica work against ticks? - briefly
Simparica protects dogs from ticks for up to 35 days after a single oral dose, with efficacy beginning within 24 hours of treatment. This duration covers the entire monthly dosing interval recommended by the manufacturer.
How many days does Simparica work against ticks? - in detail
Simparica is an oral chewable tablet that contains the ectoparasiticide sarolaner. The formulation is designed for a single dose administered once every month to dogs, providing continuous protection against a broad range of tick species.
The drug begins to kill ticks within a few hours after ingestion and maintains efficacy for a full month. Clinical trials have demonstrated that a single dose eliminates attached ticks for at least 35 days, which exceeds the standard 30‑day dosing interval and allows a safety margin for delayed administration.
Key data from controlled studies:
- Onset of activity: 3–4 hours post‑dose.
- Duration of efficacy: 35 days minimum against Ixodes scapularis, Dermacentor variabilis, Rhipicephalus sanguineus, and Amblyomma americanum.
- Dose‑response: 2 mg kg⁻¹ body weight achieves >95 % tick kill at 24 hours throughout the treatment period.
- Pharmacokinetics: plasma half‑life of approximately 12 days sustains therapeutic concentrations between doses.
The recommended monthly schedule aligns with the drug’s pharmacokinetic profile, ensuring that plasma levels never fall below the threshold needed for rapid tick kill. Owners who miss a dose by up to five days still retain protective activity, as the residual concentration remains effective until the next administration.
Considerations:
- Efficacy is consistent across all life stages (larvae, nymphs, adults) for the listed species.
- Resistance monitoring has shown no significant reduction in susceptibility in field isolates.
- The product is safe for dogs weighing ≥2.8 kg when given with food; adverse events are rare and generally mild.
In practice, a single chewable tablet given every 30 days provides uninterrupted protection for at least five weeks, covering the entire tick season when administered according to label instructions.