How Often Should I Treat My Dog for Fleas?

If left untreated, fleas can cause serious health implications for dogs which is why is important to treat dogs for fleas regularly and preventatively. But what do fleas look like, how common are they and what dog flea treatment should you use?

Fleas are a very common parasite of dogs and they can make life miserable for your canine companion. They don't restrict themselves to the warmer months either, oh no, these pesky little blighters are around for a lot longer than we once thought. Experts say treating dogs for fleas every month is the best approach.

Fleas will feed on your dog's blood as they bite and will make him itchy. They also are the intermediate host for the common tapeworm, so if your dog has fleas, he’s very likely to have tapeworms too and a heavy tapeworm burden can lead to weight loss, diarrhoea and general ill thrift - so it's important to treat regularly to prevent not just cure.

But, how often should you treat your dog for fleas and what are the risks and benefits of regular dog flea treatment? That's the question we're here to answer (alongside a few others we know are on your mind).

We have updated our advice on how often you should treat your dog for fleas for 2021 because of the changing nature of dog owner behaviour throughout the Covid-19 pandemic. Throughout 2020 there was a notable rise in the number of walks dogs were taken, particularly in the countryside. Increased exposure to the places where fleas can be picked up increases the need to dogs for fleas more frequently.

Dr Sue Huggett who holds a PhD in parasites and is the Business Manager for Beaphar UK, a pet healthcare and pharmaceutical manufacturer, has some tips addressing the most common questions about how many times dogs should be treated for fleas.

How often should I treat my dog for fleas?

Dogs should be treated for fleas monthly (or every other month depending on the product you use) all year round to try and prevent dogs from developing a flea problem and infesting the home.

The most important way to prevent a flea problem developing in your home is to treat every area that your dog has access to with a the help of products that kill flea infestations.

Browse products that kill fleas in your home. ⇢

How often should I treat my dog for fleas?

Depending on which product you buy, these are effective for between three and 12 months, Dr Huggett told us and explained more.

"Most veterinary medicines that you apply to your dog to kill fleas should be used monthly to effectively prevent a flea infestation. However, when using any veterinary medicine it’s important to carefully read the label and follow the instructions to ensure that the product will work properly, but also to ensure that you don't overdose your dog."

How common are fleas on dogs?

Fleas are more common than you might think. The flea’s life cycle consists of four stages: adult flea, flea egg, flea larva and flea pupae. Only the adult fleas live on your dog. All the other life stages live in the environment of the dog, for example, his bed, the carpets, your sofa cushions, the car.

Therefore, to make any inroads into controlling a flea infestation, it's essential to treat your dog's environment as well as your dog.

How Often Should I Treat My Dog for Fleas?

Dr Sue Huggett explains the best way to break the flea cycle.

"A good home flea spray will be effective for many months against the flea eggs and larvae, but, unfortunately, there are no chemicals on the market that can kill the flea when it’s in its pupal stage. This can result in it taking several weeks for the infestation to be cleared, since all the pupae have to hatch out in order to be killed.

"Fleas are usually more active during the warmer months, when temperatures remain above 10°C both indoors and outside. However, due to central heating and a warming climate, fleas have become a permanent problem for dogs all year round. Any gaps in preventative flea treatment, at any time of year, can allow fleas to complete their life cycle.

"Fleas can remain dormant in their pupal stage for many months, hatching out when conditions are optimal. This means a flea infestation can appear several months after the treatment was missed, making it desirable for dog owners to treat their pets and their home regularly all year round to prevent a flea infestation taking hold."

4 ways fleas can impact a dog’s health

Everybody knows when their dog has fleas; constant scratching and obvious discomfort are plain for all to see. But fleas do not just cause uncomfortable and itchy bites, they can actually cause potentially serious issues resulting in health problems.

How Often Should I Treat My Dog for Fleas?

Here are the four most common ways dog fleas can impact on a dog’s health and wellbeing, according to Dr Huggett.

Skin problems

Severe itching and scratching can result in fur loss, and broken and bleeding skin, which can result in skin infections.


Fleas also act as an intermediate host for some types of tapeworm. Your dog unknowingly ingests infected fleas whilst grooming, resulting in constant re-infestation with tapeworms.

Flea Allergy Dermatitis (FAD)

Flea bites can trigger an allergic reaction in sensitive pets and humans.

When bitten by a flea, the injection of their saliva causes the skin to become red and inflamed, which is incredibly painful and itchy. If aggravated through scratching or chewing, these bites may become infected, leading to further problems.


Fleas can drink up to 15 times their own weight in blood per day, so a heavy flea infestation can mean your dog won’t have enough red blood cells to remain healthy and carry oxygen to other parts of the body.

Read more about anaemia in dogs ⇢

Tooth damage

Hair is very abrasive and constant chewing on itchy skin can cause your dog’s incisors to wear down. This can eventually cause tooth pain and dental problems.

Read more about caring for your dog's teeth ⇢

How to tell if a dog has fleas

There are two ways to effectively check a dog for fleas; using a flea comb and the wet paper test.

How Often Should I Treat My Dog for Fleas?

Dr Huggett told us that sometimes it may be necessary to use a combination of these techniques and explained how to tell grit from flea dirt.

Using a flea comb

The spines on a flea comb are far smaller and closer together than a normal brush or grooming comb, meaning the fleas become lodged between the spines of the comb. After thoroughly combing an area, stop and look at the comb’s teeth to see if they have trapped any fleas.

The wet paper test to check for fleas

Flea dirt (flea faeces) consists of undigested blood, so when this grit-like material is applied to a wet or damp surface, red, pink or reddish-brown circles can be seen. Select a flea comb or brush, and stand your dog over a piece of wet, white paper or a wet, white sheet.

Examples of flea dirt after grooming a dog, identified by red-brown circles
Examples of flea dirt after grooming a dog, identified by red-brown circles

Thoroughly brush their coat, ensuring any dirt and grit falls onto the white paper. Adult fleas falling from the coat will be easy to identify on the white paper. If any red-brown circles form on the white paper, this is a positive indication of flea dirt.

Dog flea treatment

To break the flea lifecycle, if your dog has fleas you need to treat both your dog and your home.

How Often Should I Treat My Dog for Fleas?

How to get rid of dog fleas in your home (2 steps)

1. Treat your pet with a product to kill any fleas already living on it

Use a licensed veterinary medicine product (look for the Vm number on the pack) which has been proven to kill fleas. Be sure to read the packaging carefully to make sure it’s suitable for your dog and you use it correctly.

2. Vacuum floors and soft furnishings, and wash pet bedding at 60°C on a regular basis

Treat the house and the car with a household flea spray containing an Insect Growth Regulator (IGR) focusing on carpets, skirting boards, and any cracks or crevices in wood or laminate flooring.

What vacuum cleaners are best for dog owning homes ⇢

While you can't kill fleas in their pupal stage, the vibrations from the vacuum will stimulate the pupae to hatch out into adult fleas so they can then be killed by the insecticide that you have applied.

Turn the heating up and place damp towels on radiators – fleas like a warm humid environment and this also encourages pupae to hatch out. Reapply your chosen on-animal flea treatment at the label-recommended interval, or fit a new flea collar. Worm pets regularly as fleas carry and transmit some types of tapeworm.

To combat a flea infestation in the home effectively, it is important to disrupt the flea life cycle. Just treating the fleas on the animal will not solve a flea problem. 95% of a flea problem is in the environment. All aspects of the flea life cycle need to be taken into consideration; the adult fleas on the pet and the developing stages in the environment.

What is the difference between veterinary flea treatments & over the counter (otc) flea treatments?

There are well-known veterinary and over-the-counter brands of treatment for dogs.

We asked Dr Huggett to explain what the differences are between flea treatments supplied by vets and flea treatments you can buy at the supermarket.

"The main difference is that over-the-counter flea products have been proven to be sufficiently safe and easy to use that they don’t require the added advice of a veterinary professional.

"Any medicine, regardless of whether it’s sold over-the-counter or prescribed by a vet, has to go through the same stringent testing for efficacy and safety to be granted a licence for sale.

"You can tell if a product is a licenced medicine by looking on the pack for a number preceded by the letters ‘Vm’. Over-the-counter veterinary medicines will also bear an AVM-GSL symbol, like the one pictured. All licenced medicines are proven to do what the label says.

An example of a 'Vm' number on licenced pet medication
An example of a 'Vm' number 

"Therefore, if an over-the-counter flea treatment says it will kill fleas, then that’s exactly what it will do. If you are unsure of the most suitable product for your dog, speak to your specialist pet retailer or vet."

This article is sponsored by Beaphar UK

Make sure you keep the bugs at bay and avoid a flea infestation this summer by using Beaphar FIPROtec® Spot-On for Dogs alongside your usual household flea product. Beaphar FIPROtec® Spot-On is a fully licensed veterinary medicine that kills fleas, and keeps on working for up to 5 weeks.

How Often Should I Treat My Dog for Fleas?

Beaphar FIPROtec® Spot-On is non-systemic, meaning parasites are killed through contact. A flea or tick doesn’t have to bite your pet to killed, helping reduce the spread of disease. The active ingredient, fipronil, kills parasites through hyperexcitation. This is why you initially appear to see ‘more fleas’ after using a fipronil treatment, as fleas become more active prior to death.

To ensure your dog’s flea treatment is fully effective, you must treat your home as well. Our Beaphar FLEAtec Household Flea Spray is ideal to use alongside Beaphar FIPROtec® Spot-On.

Beaphar FLEAtec Household Flea Spray is effective for up to 6 months, and targets the flea life stages that are living in the environment. Using both products will give the best protection for your pet and your home, and keep fleas at bay this summer.

Summary: How often should I treat my dog for fleas

  • Treat your dog for fleas monthly (as a minimum)
  • Always check your dog for signs of new flea infestations even if you treated them recently
  • When you know your dog has fleas, you need to treat all areas of your home for fleas too
  • Use proven flea treatment to treat your dog both curatively and prevtatively

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