Flea bombs can be dangerous to cats.

Permethrin Toxicity in Cats:


  • One Flea can lay up to 1000 eggs a week
  • These can in warm seasons hatch into adult fleas in 1-2 weeks
  • One Flea can last up to 10 days
  • Immature stages of the flea life cycle can lay dormant in the house environment for up to 12 months before hatching and hatch with movement especially animal movement.

What we recommend:

  • Careful and ongoing monthly flea prevention application to the back of the neck
  • In some cases we need tablets on a daily or monthly basis
  • Careful environmental decontamination

As painful as fleas can be, it is also important when treating your pets for fleas that you use products appropriate for them.

Some gentle reminders include:

  1. Permethrin and permoxin products (only in dog products) is highly toxic to our feline friends.
  2. Indoor only animals will still need to be treated on a regular basis to prevent infestations breeding – yourself and visitors (both human and animals) can be a great way into the home for fleas.
  3. Flea bombs are a great way of treating the environment but be sure to remove pets and other family members from the home whilst they are being let off. Be sure to check in all the nooks and crannies of the rooms as sometimes a dear friend can be hiding away!

‘Ginger’ is a 15 year old domestic shorthair who lives in a multi pet household. As a preventative measure, her owner wanted to flea bomb bedrooms in the household to ensure that there was no chance of fleas breeding. A Mortein flea bomb was purchased –(these can be effective as long as they contain an insect growth regulator) and placed into the bedroom for aerolisation.

A few hours later (as indicated by the instructions) the room was reopened and Ginger ran out of the room ‘mort’-ified. A prompt phone call ensued and Ginger was brought down to VetHQ for a consultation.

The concern arises from the active ingredients that are used in the mortein flea bomb – it contains permethrin and fenoxycarb. Both these ingredients are great for killing fleas and insects, but similarly when permethrin aerolises and the cat ingests the ingredient whilst grooming – seizures, tremors and death can occur.

80E2748D6155AC9B5EDB461CA3DB8062Ginger was admitted into hospital – her vital signs (temperature, respiratory rate and heart rate) were generally within normal limits and she had no evidence of twitching, or tremors. She was given intravenous fluids to flush out her system and provide supportive care (as directed by poisons hotline) and a mild sedation was given to allow us to wash her to remove all traces of the permethrin and fenoxycarb.

Ginger boarded overnight – allowing us to ensure that there was no evidence of any adverse effect from her startling adventures, and was discharged the following day. She is a very lucky girl and has probably one less of her ‘nine lives.’


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