all you need to know about fleas on your cat

All you need to know about fleas on your cat


Last updated August 2023


They’re something we all dread and it makes us itch just thinking about them….fleas! Unfortunately, all cats can be at risk of picking up these mini-jumping vampires so it’s important you know how to identify and treat for them, or better yet – prevent them in the first place!



What does a cat flea look like?

The cat flea (Ctenocephalides felis) is actually the most common type of flea found on cats and dogs in the UK. In fact, around 90% of fleas found on cats and dogs in the UK are cat fleas.1


These tiny jumping insects are about 1.5-3.2mm long and are a dark reddish-brown colour. They have powerful legs for jumping – so they can hop onto poor, unsuspecting victims – and their bodies are flattened side to side to allow them to move easily through fur.

cat fleas


How does my cat get fleas?

As we’ve said, all cats are at risk of picking up fleas – even indoor cats. Fleas hop onto your pet when they are out and about, but those pesky blighters can sneak into your home too – either the adults bringing in directly, or the eggs catching a lift on you or something else coming indoors. Contrary to popular belief, fleas very rarely hop from animal to animal2 – once they’ve found their mobile home, they tend to stay! The fleas that hop onto your poor four-legged friends are most often newly emerged adults looking for their first blood meal.


These newly emerged adults can be lurking anywhere! They particularly love shaded vegetation, sandy areas and hanging out in debris on the ground, as well as your carpets and soft furnishings, of course! You may even move into a home with unwanted lodgers, as baby fleas can lie dormant for up to 5 months!3



What are the signs that my cat has fleas?

Fleas are pesky little blighters that live on your pet, biting them and sucking their blood. They move quickly and are pretty tiny so can be hard to spot, but there are some tell-tale signs to look out for…


  • More itching, scratching or chewing than normal
  • Flea bites – tiny, red bumps
  • Irritated and dry skin from all that scratching
  • Hair loss
  • Flea dirt – we have more on this below!


Some cats are even allergic to fleas – specifically their saliva. This is known as flea allergy dermatitis (FAD) and causes serious itchiness and sore skin! We have more on this uncomfortable condition here, and you can find out more about the other problems fleas can cause in ‘Fleas – more than just a nuisance’.




How do I check if my cat has fleas?

So, if you think your cat might have fleas, or just want to do a quick check for peace of mind, looking for flea dirt (yes, flea poo!) is often the best way.


You’ll need a flea comb and some kitchen roll, toilet roll or cotton wool.


  1. Run the comb gently through your pet’s fur, making contact with the skin
  2. After each stroke, tap the comb onto the kitchen roll
  3. Look for little black bits, and if present dampen with a bit of water
  4. If they stain the kitchen roll red/brown your pet has fleas (sorry!)


flea comb



How do I treat my cat’s fleas?

If your cat has fleas, don’t panic, it happens – in fact research has shown that over 28% of cats are infested with these little blighters!1 But, it’s time to take action!  


First, you need to treat your four-legged friend with a trusted and effective flea product. Fipnil Plus kills both fleas and ticks, and has the added benefit of stopping the development of flea eggs, larvae and pupae within your home. Imidaflea kills adult fleas on your pet, and flea larvae in the home. These spot-ons are highly effective and easy to apply – we even have a handy guide of how to apply spot-ons here. It’s also important that you treat all of your pets, as if one has fleas, the others will have them too! Helpfully, Fipnil Plus and Imidaflea are available for both cats and dogs.


cat fleas

Secondly, you need to tackle the environment. Wash all your pets’ bedding on a hot wash (60oC), plus anything else they regularly sleep on (we know you let them in your bed for a cuddle!), and thoroughly vacuum where your pets have been – don’t forget the sofa! Depending on the severity of infestation you may need a dedicated house treatment to help remove flea eggs, larvae and pupae from your home.


The best way to manage fleas though is to prevent them in the first place, treat your cat regularly and all year round to avoid these pesky critters from setting up camp.


cat fleas

But do I need to clean my house?

Well, this comes down to the flea lifecycle and the fact that only 5% of a flea infestation lives on your pet as adult fleas…. The other 95% is hiding away, lurking in your soft furnishings and carpets (we know, it’s like something out of a horror movie!).

flea life cycle
Why do I need to treat for fleas all year round?

Traditionally fleas have been seen as a summer problem, as they reproduce and multiply much quicker in warmer temperatures… In fact flea eggs can’t survive below 13oC, so if outdoors, they will die or fail to develop in the winter.3


There is a big BUT here… Our lovely, warm, centrally heated houses have made it possible for fleas to reproduce all year round in the comfort of our homes! Add to this the fact that those pesky pupae can lie dormant for 5 months and you have a recipe for an all year round disaster. Just imagine the scenario… Your pet picks up fleas when out and about in the summer, the unwanted creepy crawlies reproduce, with the eggs and immature stages hiding around your home, lying dormant and waiting – then months later, in the depths of winter – boom – you have fleas again!


By keeping up with regular flea treatments, all year round, you can keep your pet and home protected; we recommend treating your pet for fleas every 4 weeks when using Fipnil Plus or Imidaflea.



Can my cat’s fleas live on humans?

Luckily, we have a dedicated blog covering exactly this – ‘Can I catch fleas from my pet?’







  1. Abdullah S, Helps C et al. Pathogens in fleas collected from cats and dogs: distribution and prevalence in the UK. Parasites Vectors (2019) 12: 71.
  2. Dryden, M. W. Host association, on-host longevity and egg production of Ctenocephalides felis felis. Veterinary Parasitology34, 117–122 (1989).
  3. Silverman, J., Rust, M. K. & Reierson, D. A. Influence of Temperature and Humidity on Survival and Development of the Cat Flea, Ctenocephalides Felis (Siphonaptera: Pulicidae). Journal of Medical Entomology 18, 78–83 (1981).
  4. Byron, D. W. Aspects of the Biology, Behavior, Bionomics, and Control of Immature Stages of the Cat Flea Ctenocephalides Felis Felis (Bouché) (Siphonaptera: Pulicidae) in the Domiciliary Environment. (Virginia Polytechnic Institute and State University, 1987).
  5. Dryden, M. W. Biology of Fleas of Dogs and Cats. The Compendium on Continuing Education for the Practicing Veterinarian 15, 569–578 (1993).
  6. Krämer, F. & Mencke, N. Flea Biology and Control: The Biology of the Cat Flea, Control and Prevention with Imidacloprid in Small Animals. (Springer, 2001).