How does a tick react to Simparica? - briefly
Simparica’s sarolaner acts systemically, causing rapid paralysis and death of attached ticks within a few hours. Consequently, the parasite cannot continue feeding or transmit disease.
How does a tick react to Simparica? - in detail
Simparica (sarolaner) is administered orally to dogs, enters the bloodstream, and is distributed throughout the body’s tissues. When a tick attaches and begins to feed, it ingests the drug along with the host’s blood. Sarolaner binds to the GABA‑gated chloride channels in the tick’s nervous system, disrupting inhibitory signaling. The resulting hyper‑excitation leads to loss of coordination, paralysis, and death.
The pharmacokinetic profile of the product ensures that effective concentrations are present in the blood within two to four hours after dosing. Peak plasma levels are maintained for several days, and the drug’s half‑life of roughly four days provides continuous protection for up to 35 days. Consequently, most ticks are incapacitated before they can complete a blood meal or transmit pathogens.
Key aspects of the tick’s reaction include:
- Rapid onset of paralysis (typically within 6–12 hours of attachment).
- Cessation of feeding, prompting the tick to detach or drop off the host.
- Mortality within 24–48 hours for most common species (e.g., Rhipicephalus sanguineus, Dermacentor variabilis, Ixodes scapularis).
- Reduction of pathogen transmission risk due to early interruption of blood intake.
Resistance monitoring indicates that, to date, sarolaner retains activity against the majority of field isolates. However, repeated exposure could select for tolerant populations, underscoring the importance of rotating acaricides when feasible.
Overall, the systemic action of Simparica produces a swift, lethal effect on feeding ticks, providing both immediate relief and prolonged protection for the treated animal.