How do tick drops work on dogs? - briefly
Tick spot‑on treatments are applied to the skin, where the active ingredient spreads via the animal’s oil layer and enters the bloodstream to kill attached ticks and prevent new infestations. The formulation delivers rapid systemic protection that lasts several weeks.
How do tick drops work on dogs? - in detail
Spot‑on tick control products are applied as a single drop to the dog’s skin, usually between the shoulder blades. The formulation contains a lipophilic solvent that spreads across the coat and penetrates the outer layer of the skin, entering the sebaceous glands. From there, the active compound disperses through the lipid layer of the epidermis and is carried outward by natural oils, creating a protective film over the entire body surface.
The active ingredients vary among brands but share common mechanisms:
- Neurotoxic agents (e.g., permethrin, fipronil, sarolaner) bind to voltage‑gated sodium channels or GABA‑gated chloride channels in arthropod nerves, causing uncontrolled firing, paralysis, and death.
- Growth regulators (e.g., afoxolaner) interfere with the development of immature stages, preventing maturation into feeding adults.
- Repellents (e.g., pyrethrins) disrupt sensory receptors, discouraging attachment and feeding.
Once the compound reaches the skin surface, it remains active for a defined period—typically 30 days—during which any tick that contacts the treated area absorbs the chemical through its cuticle. The absorbed dose is sufficient to impair the tick’s nervous system within minutes, leading to rapid immobilization. Some formulations also affect attached ticks, causing them to detach before they can transmit pathogens.
Efficacy depends on proper dosing relative to the animal’s weight, correct placement of the drop onto bare skin, and avoidance of immediate bathing or excessive swimming, which can dilute the product. Systemic absorption is minimal; most of the active ingredient stays within the cutaneous layer, reducing the risk of adverse effects while maintaining high potency against ectoparasites.
In practice, application involves:
- Measuring the dose recommended for the dog’s weight class.
- Parting the fur to expose a small area of skin.
- Placing the drop directly onto the skin and allowing it to spread naturally.
- Preventing bathing or heavy water exposure for at least 24 hours to ensure full absorption.
The result is a continuous, low‑level presence of the insecticidal agent on the dog’s exterior, providing both immediate kill of contacting ticks and ongoing protection against new infestations throughout the product’s lifespan.