Permethrin Poisoning In Cats


Permethrin poisoning is one of the most commonly reported poisonings in cats worldwide and unfortunately at Castle Vets, we see cats suffering from this preventable poison quite regularly.

International Cat Care has launched a campaign to educate owners and raise awareness of Permethrin toxicity. They have also started a petition for better regulation of concentrated Permethrin-based flea products, which we would encourage pet owners to sign by visiting the International Cat Care website.


What Is Permethrin?

Permethrin is a natural insecticide that is extracted from Chrysanthemum flowers and used all over the world. Unfortunately cats are sensitive to permethrin making it highly toxic, even in small amounts, because their bodies cannot break down the chemical once it has been ingested or absorbed through the skin.

Why Do We Use Permethrin?

Permethrin is commonly used in Veterinary tick treatments, Over-The-Counter dog flea products, flea shampoos, insect repellents and insecticides because it is completely safe for most animals.

What Are The Signs Of Poisoning?

Permethrin can cause severe and sometimes fatal poisoning in cats. Signs of poisoning are usually seen very quickly but in some cases they can be delayed for up to 72 hours depending on the dose of Permethrin and how it got into the cat’s system. Permethrin is easily able to cross the blood-brain barrier of cats and it then affects the nervous system. Symptoms can include

  • Salivation (if ingested)
  • Vomiting (if ingested)
  • Muscle tremors
  • Twitching of the ears, tail and paws
  • Lack of coordination (Ataxia)
  • Seizures
  • Dilated pupils
  • Fever

Treatment can be successful if started early but often requires extensive nursing care, a decontamination bath to get rid of any product remaining on the skin and coat,  intravenous fluid therapy and sedation to treat the seizures and muscle tremors. Sadly some poisoned cats may die or need to be euthanased because of the severity of the poisoning.

If you suspect that your cat has come in to contact with Permethrin and is showing any of the above clinical  signs Contact Your Vet Immediately. Poisoned cats are more likely to survive if treatment can be given promptly

How Do Cats Get Poisoned With Permethrin? 

Most cat poisoning cases occur when cats come in to contact with dog spot-on flea products which contain the drug in higher doses. However it is worth noting that some cat flea products contain the drug in very small doses too.  The most common reasons that cats come into contact with Permethrin are;

  • The cat rubs up against, or lies next to a dog that has recently been treated with a product containing Permethrin.
  • The cat ‘grooms’ a dog that has recently been treated with a product containing Permethrin
  • Owners use a dog flea product or shampoo on their cat by accident
  • Owners use a dog flea product or shampoo on their cat because they assume that it will be safe if given in a smaller dose
  • The cat comes into contact with an insecticide containing Permethrin

Permethrin containing products in the UK

How Can I Prevent Permethrin Poisoning?

  • Never use a dog flea product on a cat – always double check the labeling before you apply anything to your pets.
  • Keep dogs and cats separate for at least 48 hours after treating the dog with a Permethrin-based product.
  • Help International Cat Care raise awareness by signing their Online Petition to reclassify Permethrin-based products and ensure that when they are sold they are properly labeled and sold by a suitably qualified person that can warn owners about the potential hazards of the product.