Permethrin cat deaths

Three tragic cases of permethrin poisoning

The accidental deaths of three cats illustrate the continuing danger of using certain dog spot-on flea products, which contain concentrated permethrin, on cats.

The insecticide permethrin is highly toxic to cats and can have severe effects and often fatal consequences. Previous reports have shown that this is the most common cause of poisoning of cats in many countries because the products are widely and easily available.


Tiddles, a little nine-week-old  black and white kitten, was taken to the Millennium Veterinary Practice in Braintree, Essex, by his owners because he was having seizures.

Veterinary surgeons there soon realised that this was because Tiddles' owners had put a dog flea product on their kitten. As responsible pet owners they had wanted to care for their pets properly and treat their dog and kitten for fleas.

They had purchased a flea spot-on treatment for dogs at their local pet store and administered it to the dog. Because the product was not very expensive, Tiddles' owners assumed that it was ‘not strong’ and would be fine for the kitten as well (despite a warning on the pack). Unfortunately the product contained concentrated permethrin which should never be used on cats. 

The veterinary practice was unable to save the kitten.

Cat Advocate for the practice, which is a Cat Friendly Clinic, Gary Rutland, said:

Having worked as a veterinary nurse for 15 years, I have seen my fair share of distressing cases, but my heart breaks when a kitten dies unnecessarily from something as simple and preventable as using the wrong flea treatment. The veterinary team worked hard into the night to try and save Tiddles but our efforts were in vain (the harrowing video above shows Tiddles having seizures). We encourage all owners to treat their pets for fleas and worms, but people need to be aware of the risks of buying these products off the shelf without the appropriate advice.

FiFi and Whitey



Donna had run out of flea treatment so she popped out to her local shop and grabbed a pack off the shelf. Without her glasses on, she did not realise she had picked up a dog product which had been put among the cat treatments. That evening she applied the treatment to her beloved seven-year-old cats FiFi and Whitey.

Within a few hours of going to bed Donna and her husband were awoken by sounds of very loud crying to find that both their cats were having seizures, shaking, being sick and were extremely distressed. They immediately took them to the vet. The cats were put on a drip and given emergency treatment, but the practice was unable to save them.

Donna and her husband are devastated and overcome with guilt at having given a treatment, albeit accidentally and with the best of intentions, with such a terrible outcome. Donna couldn’t stop crying and is determined to get the message out to cat owners about products which, although they are fine for dogs, she says are 'sold on the shelves just like selling smarties in a children's candy store'. She didn’t realise that a dog product could kill her cats and that such a simple mistake would have such terrible consequences.

The problem

Both owners had been trying to do the right thing for their pets by treating them for fleas. A spot-on product is one which makes flea treatment very easy – the hair is parted on the back of the animal’s neck and the small volume of  liquid from the vial is released onto the skin (see picture right). This technology has revolutionised treating cats for fleas, removing the need for messy powders or sprays which stressed cats and made treatment difficult.

Cat flea spot-on treatments do not contain permethrin and many newer dog spot-on products do not either (other active ingredients that are safe for both dogs and cats include fipronil, imidacloprid and indoxacarb). Unfortunately instead of using cat products, both owners used products designed for dogs which contained concentrated permethrin, with fatal outcomes for their cats. 

Dogs are far less sensitive to the toxic effects of permethrin and such products are safe to use on dogs. Both products did have a warning on the pack that they could be toxic to cats and were not to be used on cats, but these two cases illustrate how easily mistakes can be made. There is also a risk to cats which come into contact with recently treated dogs if the product is groomed off the dog or rubs off onto the cat. 

Our campaign

International Cat Care is asking that such products should not be available without verbal advice at the point of sale. Currently these products are categorised by the Veterinary Medicines Directorate (VMD) in the UK as Authorised Veterinary Medicine-General Sales List (AVM-GSL), which means that they can be bought directly off the shop shelf without the need for advice. The same is true in many countries.

Claire Bessant, Chief Executive of International Cat Care, comments:

This is a worldwide problem wherever permethrin products are poorly regulated. The charity is campaigning to have these products recategorised so that they can only be purchased if  there is someone in the shop to advise the buyer that they are only for use on dogs. Owners should also be asked if there are cats in the home and advised accordingly. These cat deaths are totally preventable – please sign our petition to have them recategorised. We applaud Pets at Home who have joined the campaign and will be putting safeguards on the sale of these products into their shops - International Cat Care wants other pet shops to do the same.

Maeve Moorcroft, Head of Pets at Pets at Home, which earlier this year launched its Flea Fight Force, said:

We take the risk of permethrin poisoning in cats very seriously.  We are introducing prompts at our tills so that customers are asked during the checkout process if they are aware of the risk to cats in the home when purchasing a permethrin-based spot-on dog flea treatment, and also advised to wait at least 72 hours after treating the dog before the dog and cat can come into close contact.


Our advice to cat owners:

  • Support our campaign to  ensure that permethrin-containing dog spot-on products are only to be sold with advice, either through veterinary surgeons or shops where there are suitably qualified people to advise pet owners – sign our petition
  • Never purposely use dog flea spot-on products on cats.
  • Never scale down dog treatment to fit a cat – even a small dose can be lethal.  A cat is not a small dog.
  • Where there are cats and dogs in the same house do not use a dog spot-on which contains permethrin (there are many flea products for dogs which do not contain this chemical).  If you do use one, keep the cat and dog separate for 72 hours.
  • Always read the pack and heed warnings – just because a product is cheap and easily available does not mean that it cannot cause harm.
  • Treatment for fleas is important to cat health – choose the right product and, if in doubt, ask your vet. There are many safe and effective flea spot-ons and other types of flea treatment which are suitable for cats.
  • Store dog and cat products separately at home – it is very easy to mix up the small pipettes from multi-treatment packs and use the wrong one.
  • If you have applied any spot-on product containing permethrin onto your cat by accident, wash off the product at once with water and a mild detergent and seek immediate treatment from your veterinary surgeon. Take the product package with you and show it to your vet.
  • If you have an incident  where your cat is poisoned by a permethrin product (whether it is fatal or not) make sure you contact the VMD ( and report the problem. All too often it is not reported, the true number of cases is not recorded, and nothing is done.
  • Check what you have in the kitchen drawer – see our list of permethrin-containing dog spot-on products.


International Cat Care is also:

  • Encouraging pet shops to separate dog and cat flea products totally in displays and, if they stock the type containing permethrin, to have large signs to say that dog products could be lethal for cats.
  • Asking pet shops to treat the dog flea spot-on products containing permethrin as a different category of medicine which should only be sold to owners with verbal advice given about their safe use.
  • Urging manufacturers to  have even larger warnings both on the pack and on the individual treatment vials and packaging.
  • Asking shops to stock only non-permethrin-containing products if owners cannot be warned properly.
  • Making advice on the treatment of cats with permethrin poisoning freely available for vets.
  • Contacting online sellers of flea products, including Amazon, and asking for clear warnings on the product purchase page.
  • Asking vets to report any poisonings they treat to the VMD.