Flea products for dogs (Over-the-counter and Prescription)

When a dog has fleas, you’ll need to apply a flea product that kills the adult fleas (an adulticide). This is an essential part of treatment. But what’s the best treatment to use?

Treatments can be

  • Over-the-counter (available from pharmacies, pet shops, online etc)
  • Prescription only (available from your vet or from pharmacies and online with a valid prescription from your vet)

And there are options for

  • Tablets
  • Spot-on liquids (topical products)
  • Flea collars
  • Shampoos

In the following section, we’ll break down all of the flea products available for dogs in the UK.

Over-the-counter flea treatments for dogs

Many over the counter flea products can be bought without a prescription from pharmacies and pet shops as well as online. Technically, the legal category for these products is either NFA-VPS (which stands for ‘non food animal – veterinarian, pharmacist, or suitably qualified person’) and means the person supplying the drug must have had some training to ensure safe use, or AVM-GSL, which means there are no restrictions on sale.


There are only three adult-killing drugs licensed for over-the-counter spot-on flea treatments in the UK. These are fipronil, imidacloprid, and pyriprole.

Some products also contain (S)-methoprene, which kills some of the immature stages of the flea to allow for faster control.

Fipronil-based products

Fipronil is the most common topical flea treatment in the UK. It’s an active ingredient found in:

  • Frontline Plus, Frontline Combo, Frontline Spray, and Frontline Tri-Act
  • FIPROtec, FIPROtec Combo, and FIPROtec Spray
  • Effipro, Effipro DUO, and Effipro Spray
  • Fipnil
  • Flevox
  • Fleascreen combo
  • Itch
  • Bob Martin Clear Plus

In other words, all of these treatments contain the same adulticide – fipronil. So while it may seem like there’s a lot of choice when you go to the pet shop, most of these contain the same active ingredients and it’s only the branding that varies.

Imidacloprid-based products

Imidacloprid is less common, but still available in most shops. Products that use this drug as the active ingredient include:

  • Advantage
  • Johnsons 4Fleas Spot On
  • Imidaflea

Pyriprole-based products

Pyriprole isn’t a commonly used drug, but it can be found in:

  • Prac-tic spot on solution

In all cases, there are also prescription-only drugs that contain these active ingredients, but usually alongside other drugs (which is why they end up as prescription-only).

Listen to the audio note to hear more information about fipronil and imidacloprid-based products


The only non-prescription flea tablet ingredient is nitenpyram. It’s the active ingredient in:

  • Capstar
  • Johnsons 4Fleas Tablets
  • Bob Martin Clear One Dose Tablets

This fast-acting insecticide kills adult fleas feeding on your pet within minutes, but only stays in the body for around 24 hours.

It’s really effective at de-fleaing strays before they enter the house, but due to the really short action isn’t suitable for controlling an infestation.

Remember, as soon as fleas have laid eggs, you need to treat for 12-20 weeks, depending on the product you’re using. Doing that with a daily tablet is likely to be ineffective!

Flea collars

Various flea collars are available, and they’re split into ones that kill fleas, and ones that just repel fleas. To treat an active infestation, you’ll need the type that kills fleas. Collars of this type contain

  • Permethrin, and derivatives (deltamethrin, flumethrin)
  • Dimpylate

Permethrin-based collars

Collars that use permethrin as the active ingredient include:

  • Beaphar flea collars (permethrin)
  • Scalibor (deltamethrin)
  • Beaphar Canishield (deltamethrin)
  • Seresto collar (flumethrin)

Dimpylate (aka diazinon)-based collars

Collars that use dimpylate as the active ingredient include:

  • Johnsons Flea and Tick Collar for Dogs

Please note that permethrin is fatally toxic to cats in high enough doses so you should never apply a dog product to a cat.

Flea shampoos

Flea shampoos are usually repellent products – they leave a scent on the coat that is unattractive to fleas. Additionally, they work by physically washing the fleas from the coat. However, flea-killing shampoos are available with the active ingredients:

  • Pyrethrins (a permethrin derivative)

Pyrethrin-based shampoos

Products containing this shampoo include:

  • Beaphar Dog Flea Shampoo

Please note that flea shampoos containing an insecticide are bad for the environment. Insecticide residues in the water will be washed into waterways, causing huge environmental harm.

In addition, shampoos strip the natural oil from the coat, which many spot-ons and collars depend on for them to work properly.

Prescription flea treatments for dogs

A huge range of different flea drugs are available as POM-V (which stands for ‘prescription only medicine – veterinary). Like the over-the-counter options, they are available in many forms, but not shampoos or flea collars. They’re more likely to be modern medicines or contain a number of active ingredients which allows them to work on other parasites as well. Let’s take a look at the options for flea treatment available with a prescription.


When it comes to prescription-only medication, spot-ons are still widely used, as they’re simple and easy to apply. These topical treatments may include drugs like our familiar friends Imidacloprid, Fipronil, and S-methoprene, but they’re POM-V because they’re now in combination with other drugs like:

  • Moxidectin (eg Advocate, Moxiclear, Prinovox, Prinocate)
  • Permethrin (eg Advantix)

These spot-ons may also include active ingredients like

  • Fluralaner (eg Bravecto Spot-on)
  • Dinotefuran, Permethrin and Pyriproxyfen (eg Vectra 3D)
  • Selamectin (eg Stronghold, Evicto)


More recent advances in flea control have been based around oral chewable ‘tablets’ that are long-lasting. Because they are tablets, they have the advantage that they aren’t washed off if dogs are bathed or go for a swim, and the hope is that there will be less environmental contamination. Tablets can include:

  • Fluralaner (Bravecto)
  • Afoxolaner (Nexguard, Nexguard Spectra)
  • Sarolaner (Simparica)
  • Lotilaner (Credelio)
  • Lufenuron (PROGRAM)
  • Spinosad (Comfortis)

How do I choose a product?

Deciding on a suitable product for your dog is tricky at first glance, as there seem to be a lot of options. You’ll need to consider:

  • What you’ve used before, and whether it worked
  • Your pet’s lifestyle – do they bath or swim?
  • Your pet’s other parasite risks – do they need lungworm protection? What about tick protection?
  • How many pets are in the house, and what species they are – have you got cats, ruling out permethrin as a safe option? Are there so many pets that it’s going to be difficult to treat them all with prescription products?
  • Whether your pet shows signs of flea allergy (FAD)
  • What breed your dog is, and whether they have any prior medical conditions

Which flea treatment is the best?

There are lots of possible flea treatments, and none is ‘best’ because they all suit different pets differently.

However, we can narrow down options quickly. For non-prescription options, spot-ons are the only good long-term solution. If you’ve previously struggled with a fipronil product, you should try one containing imidacloprid.

Prescription options normally give you more choice. For instance, there are tablets available that can provide 12 weeks of continual cover from a single tablet – a fantastic, easy option, especially for those dogs that swim. Prescription products may also treat more parasites, and they come with the benefit that a vet can help you choose a product and give you personalised advice. This means they often seem to be more effective, as the product will be individually chosen for your pets.


Whatever you choose, you will need to treat all the animals in the house continually for 12-20 weeks, without a break in cover.

Getting a prescription for a flea product

If you’ve decided that you want a prescription flea product, your next question will be how to get hold of a prescription.

Under UK law, vets must examine a pet in order to write a prescription for them. In some cases, this has already been done – for instance, at a recent vaccination. However, new laws mean that the prescription has to be made at the time of the examination (even if you don’t take the product).

This may mean that your pet was vaccinated last week, but if you declined flea treatment at the time your pet may not have an active prescription. In some cases, this will mean your vet cannot legally prescribe the flea treatment without seeing your pet again.

Once your vet has written the type of product, dose, and frequency to be applied to your dog’s notes, this is now a ‘prescription’. You can either purchase the product from the vet now, or ask for this prescription to be a ‘written prescription’, which means you can take it to another pharmacy or online pharmacy that stocks the medication, and they can get it for you. Written prescriptions may incur a fee.


Only a very limited number of drugs are available without a veterinary prescription, and most of the choice you see is different brands but the same active ingredient. On the other hand, prescription products have a wide variety of active ingredients. If you’ve struggled with non-prescription products in the past, it might be worth trying prescription products – you’ll need to see the vet for this. Check with your local vet to see what they can offer you.

Key Takeaway

Choosing the drug that suits your pets can be difficult. If you’re stuck, head to your vet – they can write you a prescription or just advise you on which over-the-counter product best suits your needs.