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Permethrin

Permethrin and Pets

Find out if Permethrin is toxic to dogs and cats.

Dogs: Limited
Cats: Toxic

Think your pet ate something toxic?

Call ASPCA Animal Poison Control Center: (888) 426-4435 or view emergency guide

Permethrin is a synthetic pyrethroid insecticide widely used in dog flea and tick products, including spot-ons, sprays, shampoos, and premise treatments. While it is commonly used in canine formulations, it is extremely toxic to cats and is a leading cause of feline poisoning. Cats lack the liver enzymes needed to efficiently metabolize permethrin, so even a tiny dose can produce severe neurologic symptoms within hours.

Exposure in cats usually happens when owners accidentally apply a dog flea product to a cat, when a cat grooms or contacts a recently treated dog, or when cats share bedding with a treated dog. In dogs, toxicity is less common but can occur with overdose, use of highly concentrated livestock products, or ingestion of treated collars. Cats exposed to permethrin may develop muscle tremors, seizures, hypersalivation, vomiting, ataxia, hyperexcitability, weakness, and respiratory distress, and can die without rapid treatment.

To prevent poisoning, never use permethrin-containing dog products on cats, and keep cats separated from dogs treated with high-concentration permethrin spot-ons for at least 24–72 hours. Read all labels carefully, use only species-appropriate and weight-appropriate formulations, and store all pesticides well out of reach of pets. If you suspect any exposure, treat it as an emergency and contact a veterinarian immediately.

Is Permethrin Toxic to Dogs?

Generally tolerated when canine-formulated products are used exactly as directed, but high-concentration spot-ons or ingestion can cause neurologic signs.

Is Permethrin Toxic to Cats?

Extremely toxic to cats; even small amounts from dog flea products or contact with treated dogs can cause tremors, seizures, and death.

Active Ingredients

  • permethrin

Pest Targeted

  • fleas
  • ticks
  • mosquitoes
  • mites

Formulation

spot-onsprayshampoopowderpremise spray

Signal Word

caution

Application Area

pet coathousehold premisesoutdoor premises

EPA Registration Number

EPA Reg. No. varies by product

Symptoms to Watch For

  • tremors
  • seizures
  • muscle twitching
  • hypersalivation
  • vomiting
  • ataxia
  • hyperexcitability
  • weakness
  • respiratory distress
  • death

What If My Pet Was Exposed to Permethrin?

If a cat is exposed to permethrin, bathe the animal immediately with mild dish soap and lukewarm water and seek emergency veterinary care without delay. For dogs, contact a veterinarian or pet poison helpline if any signs develop.

Safer Alternatives

Sources

Vet's Note

PetPilot provides general information for educational purposes. While we reference authoritative veterinary organizations, this page has not been individually reviewed by a veterinarian for your specific pet. Individual animals may react differently based on age, weight, breed, health conditions, and amount consumed. Always consult your veterinarian or a poison control center for personalized advice, especially if your pet is ill, injured, pregnant, nursing, or on medication.

Medical DisclaimerThe content on this page is not a substitute for professional veterinary diagnosis, treatment, or emergency care. If you suspect your pet has been exposed to something harmful, contact your veterinarian or call ASPCA Poison Control or Pet Poison Helpline immediately.