How does a tick die from Simparica? - briefly
Sarolaner, the active ingredient in Simparica, binds to GABA‑ and glutamate‑gated chloride channels in the tick’s nervous system, causing uncontrolled neuronal firing, paralysis, and rapid death. The effect occurs within hours after the tick attaches and ingests the medication through the host’s blood.
How does a tick die from Simparica? - in detail
Simparica contains the active compound afoxolaner, a member of the isoxazoline class. After a dog ingests the chewable tablet, the substance is rapidly absorbed into the bloodstream and distributed throughout the body’s tissues. When a tick attaches and begins feeding, it ingests blood that already contains therapeutic concentrations of the drug.
The insecticide acts on the tick’s nervous system by selectively blocking GABA‑gated chloride channels and, to a lesser extent, glutamate‑gated channels. This blockage prevents the influx of chloride ions, causing uncontrolled neuronal firing. The resulting hyperexcitation produces tremors, loss of coordination, paralysis, and ultimately cessation of vital functions.
Key points of the lethal process:
- Ingestion – tick consumes blood with afoxolaner during feeding.
- Neuroreceptor binding – compound binds to inhibitory neurotransmitter receptors.
- Ion imbalance – chloride flow is disrupted, leading to neuronal overactivity.
- Physiological collapse – muscle spasms and paralysis impair respiration and feeding.
- Death – irreversible damage leads to mortality within 24–48 hours after attachment.
The speed of kill varies with tick species and life stage. Adult ticks are typically eliminated within 8–12 hours, while larvae and nymphs may require up to 24 hours. Because the drug remains in the host’s circulation for several weeks, any tick that attaches during this period will be exposed to lethal concentrations, preventing disease transmission.