Fleas on cats


  • Fleas are a common problem that most pet owners have to deal with at some point.
  • As well as being extremely irritating, fleas can lead to skin problems, allergic skin disease and in some cases serious conditions such as anaemia (blood loss).
  • 95% of a flea problem lives in the home – if your cat has fleas, your home does too!
  • Prevent fleas by regularly treating your pets (and home) with a licensed flea product.

General information

Fleas are tiny insects that bite and cause itchy skin. They can lead to skin problems, especially in cats with flea allergies, and can even cause anaemia (blood loss) in kittens. Fleas are most common during the summer months and can be caught from other animals, the outdoors, or from your home (if they’ve been brought in on shoes or clothes). 

How to tell if your cat has fleas

Not all cats with fleas have symptoms, but you may notice the following:

Photo of flea dirt in a cat's fur

Flea dirt in fur

When to contact your vet

If you think your cat has fleas, call your vet practice for advice. If they have had a vet check recently, it’s likely you’ll be able to collect a flea product without them being seen, but if they haven’t been examined in a while, or have developed skin problems due to fleas, they will need an appointment.

How to get rid of fleas

To treat fleas you need to:

Treat your cat - treat your cat and any other cats, dogs and rabbits in the house (on the same day). Ideally use a prescription product from your vets, but if this isn’t possible, use an NFA-VPS product. Products you can buy of the shelf, without a prescription (e.g. from a supermarket or pet shop) often contain less effective ingredients

Treat your home - 95% of a flea infestation is in the home, this means that if your cat has fifty fleas on them, your home is likely to have up to one thousand fleas and eggs - and they can survive for up to a year! You can buy household flea spray from your vets or online.

WARNING: Never put a dog flea treatment or a household flea spray on a cat. They often contain ‘permethrin', which is extremely poisonous to cats (as well as fish and birds). Contact your vet immediately if your cat has come into contact with a dog flea treatment, or household flea spray.

Other necessary treatment. Fleas can transmit worms, so your cat should be wormed at the same time as being treated for fleas. They may also need treatment for their skin if they have developed sores/irritation.



Illustration showing how fleas can live on pets and around the home

Most of a flea problem is in the home, 50 fleas living on your cat = 1000 fleas in the home

Which flea treatment?

There are three types of flea treatment available:

Prescription flea treatments - proven and effective products that can only be prescribed by a vet. If your cat is healthy and visits your vet regularly, your surgery may be happy to dispense prescription flea products without an appointment, but if they haven’t been examined for a while, you will need to book an appointment for them to be checked.

Non-prescription flea treatments:

  • ‘Off the shelf’ treatments - these can be bought ‘off the shelf’ without a prescription from supermarkets and pet shops. They tend to contain non-proven/less effective ingredients than prescription and NFA-VPS products.
  • NFA-VPS’ treatments - these can be bought without a prescription, but are only available from locked cupboards in pharmacies, vet clinics and pet shops. NFA-VPS products tend to be more effective than ‘off the shelf’ products, and you will need to know your cat’s weight to buy one.

How to weigh your cat at home

Preventing fleas

It can take a few weeks to sort out a flea problem, but once they’ve gone it's easy stop them coming back:

  • De-flea all of your cats, dogs and rabbits as regularly as your vet recommends (depends on which flea product you’re using).
  • De-flea your home once a year.
  • Keep your home clean by vacuuming regularly.
  • Keep pet bedding clean by washing it at 60°C.
  • Only allow flea-free cats, dogs and rabbits into your home.
  • Regularly check your pets for flea dirt, particularly around their back end and above the base of their tail.

Do flea collars or flea shampoos work?

Flea collars. Always speak to your vet before buying a flea collar, there are some very effective ones on the market, but also many that don’t work well at all.

Flea shampoo. Unfortunately, flea shampoo doesn’t tend to be good at killing fleas.

Can humans catch fleas?

Fleas can’t live on humans, but can bite us. If your pets have fleas, your home will too and you may notice itchy bite marks around your ankles or on your arms. Contact your pharmacist, doctor or the NHS  if you have skin irritation that’s worrying you.

What if I can’t get hold of a flea treatment for my cat?

If you are unable to get a prescription flea treatment from your veterinary practice, you may need to consider temporarily using a non-prescription product (from a pet shop, or online). If your pet has a condition that requires prescription flea treatment, it's important to contact your vet to discuss your options.

Published: July 2020

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Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.