Deltamethrin
Deltamethrin is a synthetic pyrethroid ectoparasiticide used primarily in dogs via impregnated collars to control ticks, fleas, sandflies, and mosquitoes. It provides long-lasting repellent and insecticidal activity. > **Clinical Warning:** Highly toxic to cats, aquatic animals, and bees. Do not use on cats or allow treated dogs to swim in natural waterways with the collar on.
Mechanism: Acts as a **sodium 'open channel blocker'** in the nerve membranes of arthropods. → Prolongs sodium channel opening → Causes continuous nerve depolarization → Results in muscular convulsions, paralysis, and death of the parasite. It also possesses significant repellent (anti-feeding) activity against ticks and flying insects.
Dosing by species
- Any · Do not use · Topical · null · null · Contraindicated due to severe pyrethroid toxicity in cats.
- Prevention against ticks, fleas, sandflies and mosquitoes · One collar · Topical · q5-6months · 5-6 months · Collar exerts full effect after 1 week. Canishield provides persistent flea killing activity for 16 weeks.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Cats (highly toxic)
- Dogs less than 7 weeks old
- Dogs with existing skin lesions
Adverse effects
- Dermatitis or localized skin irritation around the neck
- Gastrointestinal disturbances (if ingested)
- Neuromuscular disturbances (if ingested)
Monitoring
- Signs of local skin irritation or dermatitis at the collar site
- Neurological signs (tremors, twitching) if accidental ingestion is suspected
Overdose
Accidental ingestion of the collar can cause severe gastrointestinal and neuromuscular disturbances (tremors, hypersalivation, seizures). > **Treatment:** **Diazepam** should be administered in the event of accidental ingestion to control neurological signs. Provide supportive care.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.