When exactly is flea season in the UK?

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It’s true that fleas thrive in warm conditions, so you would be forgiven for thinking there was a flea season in the UK. But nowadays in our centrally heated houses, fleas don’t only pose a risk in the spring and summer months, they’re a year-round threat. Find out more about how fleas manage to survive, even in cold weather and when you need to act to keep your pet flea free.

cat scratching

When is flea season in the UK?

Historically, fleas tended to be active when our British weather warmed up in the spring and summer seasons. However, now we can keep our houses cosy and warm in the winter it provides the perfect conditions for them to survive 12 months of the year.

In fact, flea pupae – the cocoon stage – can lay dormant for long periods of time, waiting for the right conditions so adult fleas can emerge.

That’s why it’s important pet owners help protect their dogs and cats from fleas all year round, even during the winter months, to preserve their health and prevent a dreaded home flea infestation.

How does weather impact fleas?

Changes in the weather can help or hinder the flea life-cycle but these robust insects have plenty of survival techniques to keep them alive for 12 months of the year.

Fleas are tough little critters that can find warmth and shelter to get through the winter months by living on not just our pets, but wildlife too, such as foxes and rats, or in animal dens. If you don’t use a regular preventative, fleas can easily latch on to your pets and make themselves comfortable in your home!

Where do fleas like to live?

A flea goes through four stages during its lifecycle: egg, larvae, pupae and adult. What stage they’re at will depend on where they prefer to hang out.

On your pet

If your pet is unprotected, adult fleas will feed on them and go on to lay an average of 20 eggs every day, which your pet helps to distribute around the environment as they move

In your home

Fleas lay eggs on your pet which fall off into your home wherever your pet wanders, which means they might end up on bedding, furniture and in your carpet.

Once the eggs hatch into flea larvae, they seek out dark spaces such as under furniture and in the pile of carpets, or cracks between floorboards, that will provide protection.

The following stage, flea pupae, refers to the cocoon they create for protection before emerging as an adult. The sticky outer layer of the pupae enable them to hide deep inside the fibres of carpets and rugs.

On other animals

Fleas aren’t fussy about their hosts and many will live on wildlife, as well as pets. That means if your pet comes into contact with any wild animals in the garden, they are at risk of a flea jumping on board.

What type of fleas are there?

Fleas are a huge nuisance to our pets. When they feed on them, sucking their blood, the itchy bites can cause distress and discomfort and they can transmit diseases to pets and pose a risk to you too. 

There are many different types of fleas in the UK, but cat and dog fleas are amongst the most common and they can even bite humans too. Despite their names cat and dog fleas are not specific to either animal, as both species can be found on either a dog or a cat.  

Cat flea

Cat fleas (Ctenocephalides felis) are around 3mm long and have long legs, which they use to jump big distances.

 If a cat flea feeds on a cat that is carrying a type of bacteria in its bloodstream called Bartonella henselae, then its flea dirt can also contain this bacteria, and can be passed on to people via cat scratches or bites, resulting in a condition known as Cat Scratch Fever. Fleas can also carry the tapeworm parasite Dipylidium caninum, and if a person accidentally ingests an infected flea, it is possible for this to affect humans too, however this is very rare.

cat flea

Dog flea

The dog flea can grow up to 4mm long, and like the cat flea, is brown-black in colour.

How you can tell your pet has fleas

There are some give-away signs that your cat or dog may have picked up a pesky flea. As soon as you spot any of the below, take action immediately to prevent the infestation spreading any further.

Excessive scratching

Flea bites can be very itchy for your pet and some animals are allergic to flea saliva, a condition called flea allergy dermatitis (FAD), which makes the itching sensation even more intense and leads to severe discomfort.   

Sore or bald patches on the skin

To relieve the itch, cats and dogs will scratch a lot and may even resort to licking and biting at their irritated skin, which can cause hair loss and self-trauma.

Flea dirt

Flea dirt is the name given to flea droppings, which look like black specks on your pet’s skin. If you suspect fleas, you may want to use a fine-toothed flea comb to search your dog or cat’s fur to find evidence of fleas or droppings.

Remember, always speak to your vet if you have any concerns about your pet.

Dog sat outside scratching

What to do if your pet has fleas

If you discover your dog or cat has fleas you will need to treat them and any other pets in the household right away. You’ll then need to turn your attention to getting rid of fleas from your home. 

Treat your pet

Most preventative products will work as flea treatments too. The best way to keep your pet free from fleas is by using a regular preventative. There are plenty of different formats on the market, including collars, spot-ons, tablets and sprays so you can choose a product to suit your pet and your lifestyle.

Long lasting flea preventatives can be particularly useful if you don’t want to have to remember to apply monthly.

Seresto Flea and Tick Control collar provides 7-8 months of protection against fleas and ticks – the longest-lasting product in one treatment – for cats and dogs. It’s clinically proven to kill fleas in 24 hours and actively repel and kill ticks through contact, so no biting is required for it to work.*

Odourless, water-resistant and easy to apply, Seresto also has a safety release mechanism, perfect for exploring pets!

Treat your home

You will need to deep clean your home thoroughly to remove the different stages of fleas that will have moved in. Ensure you:

  • clean bedding regularly, as well soft furnishings and on a hot wash if possible
  • vacuum hard floors as well as carpets in each room furniture and skirting boards
  • properly dispose of the dust collected in your hoover away from the spraying house

For more information, read our guide on how to get rid of fleas in your home.

It can take at least several weeks to rid your home of an infestation, so why risk fleas? The easiest way to avoid them is to prevent fleas biting your pet.

Dog on floor whilst owner is vacuuming for fleas

Mehlhorn et al. Parasitol Res (2001) 87:198-207, information is regarding mode of action and is not intended to relate to speed of kill or to imply parasites can be completely stopped from biting.

Use Medicines Responsibly.

Seresto Flea and Tick Control collar contains imidacloprid and flumethrin (NFA-VPS). Further information is available from the datasheet at www.noahcompendium.co.uk or on request. The Bayer cross is a Registered trademark of Bayer AG. Seresto, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates. Elanco UK AH Ltd., Form 2, Bartley Wood Business Park, Bartley Way, Hook, RG27 9XA. Tel. 01256 353131

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Date of review June 2021

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