Deltamethrin
(S)-alpha-cyano-3-phenoxybenzyl (1R,3R)-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate
Also known as: Canishield · Scalibor · Deltametrina · Deltamethrinum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Prevention against ticks, fleas, sandflies and mosquitoes | One collar | Topical | q5-6months | 5-6 months | 🌍 EU |
- Prevention against ticks, fleas, sandflies and mosquitoes: Collar exerts full effect after 1 week. Canishield provides persistent flea killing activity for 16 weeks.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Any | Do not use | Topical | null | null | 🌍 EU |
- Any: Contraindicated due to severe pyrethroid toxicity in cats.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
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 of action
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.
Safety & warnings
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)
Precautions
Wash hands thoroughly after fitting the collar.
Important: Avoid letting children, especially those under 2 years of age, touch, play with, or put the collar into their mouth.
Highly toxic to aquatic animals; remove the collar before allowing the dog to swim in rivers or lakes. Also toxic to bees and birds.
Monitoring
- Signs of local skin irritation or dermatitis at the collar site
- Neurological signs (tremors, twitching) if accidental ingestion is suspected
Pharmacokinetics
Half-life
Absorption
Systemic absorption from the collar is minimal; the active ingredient spreads through the lipid layer of the skin and hair coat.
Distribution
Distributes over the entire body surface via sebum and hair.
Metabolism
Any systemically absorbed deltamethrin is rapidly metabolized by the liver (ester hydrolysis and oxidation).
Elimination
Excreted primarily in feces and urine.
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.
Available products
Formulations
- Topical: 4% deltamethrin collar (0.76 g for small/medium dogs, 1 g for large dogs)
Veterinary
- Canishield 4% collar
- Scalibor Protectorband 4% collar
Regulatory status
Regulated as a pesticide by the EPA rather than FDA.
Available OTC in many EU countries.
Non-Food Animal - Veterinarian, Pharmacist, Suitably Qualified Person.
No regulatory data for: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store in the original packaging at room temperature until ready to use.
Client information
- Do not use this collar on cats, as it is highly toxic and potentially fatal to them.
- The collar takes about 1 week to reach its full protective effect.
- Wash your hands with soap and water after handling or fitting the collar.
- Keep children (especially those under 2 years old) from playing with, touching, or chewing on the collar.
- Remove the collar before your dog goes swimming, as the medication is highly toxic to fish and other aquatic life.
- Watch for any redness, itching, or hair loss around the dog's neck. If this occurs, remove the collar and consult your veterinarian.
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.