You may have heard about the use of “natural” remedies to treat or prevent fleas. Perhaps a friend has recommended them, or you’ve come across them on a google search. The idea of using “natural” treatments might sound appealing. But do they actually work? And are they safe? This article will explore what is required for flea treatments to work effectively. And whether natural treatments are likely to get the job done. 

The flea lifecycle

When considering flea treatment options it is important to understand the flea cycle. When a flea jumps onto your pet’s coat they can lay up to 40 to 50 eggs within 24 hours. These eggs fall into the host’s environment, often our homes, and hatch into larvae. Under the correct conditions larvae can develop into the next stage of the lifecycle, known as pupae, in days. Pupae are protected by a cocoon and they are difficult to eliminate from the house. They can bury deep into carpets or furniture! Adult fleas can emerge from the pupae within as little as 3 weeks in the right conditions although it can take months or years in some cases. Warm and humid conditions can stimulate egg and larvae development and pupae hatching. Hot and humid weather or centrally heated homes without adequate airflow can provide perfect conditions for flea development. 

So why am I going into all this gruesome detail about the flea cycle? Well, it’s important to understand that during a flea infestation, 5% of the flea population are on your pet whilst the other 95% are in the home. In order to rid your pet of fleas you will need treatments, or a combination of treatments, that will work on both your pet and in the home to prevent your pet from becoming re-infested. Effective treatments should also kill as close to 100% of adult fleas on your pet as possible, before they’ve had a chance to lay eggs. Fleas left behind or killed too late could lay a large number of eggs resulting in another infestation in a few weeks.

How do regular flea treatments work?

Most flea treatments in the UK work as insecticides. This means they contain ingredients that interfere with the nervous system of the adult fleas – resulting in rapid death of the fleas before they lay eggs. Some flea treatments work before fleas even have a chance to bite. This is particularly beneficial to pets with flea allergic dermatitis – an allergic skin condition that can be triggered by a single flea bite. 

Killing fleas before they have the chance to lay eggs breaks the flea cycle – it stops further infestations from occurring. If you apply these treatments at a later stage of the flea cycle then you will also need to treat the home. You should speak to a veterinary professional about strategies to treat a flea infestation. 

Unfortunately pupae are extremely difficult to kill so if the fleas have got to the pupae stage, it will take longer to get rid of the infestation. Continual application of flea treatment to your pet, in accordance with the manufacturer’s instructions, will however ensure that adult fleas emerging from pupae are instantly killed when jumping back onto your pet’s coat. Remember that pupae can emerge after weeks, months or even years later. This is why it’s important to stay on top of the flea prevention regime recommended by your vet. 

Regular veterinary products, including flea treatments, must have a licence to be sold on the UK market

To obtain a licence, the manufacturer must conduct scientific studies to demonstrate that the product is safe and highly effective for the intended species. These studies are evaluated by an independent regulatory authority (the VMD). Once the treatments are licensed, the manufacturers must also monitor safety data. When a vet suspects that an animal has had an adverse reaction to a medication they will report it to the manufacturer who must assess the risks and alert customers where necessary. 

No effective medicine is ever 100% safe. But these studies must demonstrate how safe the products are, and if more than a very small percentage of patients develop severe side effects, the product will usually be withdrawn from the market. 

Do natural treatments work?

Natural remedies which are thought to repel fleas include:

  • Certain essential oils (used on a bandana or collar) 
  • Amber collars (made from stones of ambers threaded onto a collar)
  • Black walnut given by mouth
  • Garlic given by mouth
  • Apple cider vinegar spray

Natural remedies which are thought to treat fleas include:

  • Natural ingredient shampoos 
  • Plant-based food supplements 
  • Diatomaceous earth (a powder from the fossilised remains of single-celled algae which is said to dehydrate flea larvae and eggs in the home environment, although some websites claim it can also be used on your pets coat) 

Do they work?

Many of the websites promoting these remedies give no explanation as to why the fleas are repelled or killed, nor do they point to any evidence of effectiveness. To prevent a flea cycle from starting, a flea treatment needs to kill adult fleas before they lay eggs. Even a treatment with 90% effectiveness could still leave adult fleas alive – remember just one flea can lay 40-50 eggs. The resulting infestations could take weeks or months to treat, resulting in a lot of time, effort and cost to you and a lot of irritation to your pet. 

I personally had a look for some scientific studies that were able to show proof of effectiveness for the above remedies. I only managed to find one study, which tested the effectiveness of a natural food supplement to treat fleas in dogs. Unfortunately the sample size of the study was very small. Although it did result in a decrease in fleas compared to dogs that had received no treatment, fleas were still found on the dogs at the end of the study. 

This doesn’t mean that they don’t work – it might be that some do – but we do not have any reliable evidence to show that they are effective.

Are they safe?

Another thing to note about these remedies is that they carry potential safety concerns. For example, diatomaceous earth should not be used around pets with breathing difficulties, certain essential oils are toxic to pets and black walnut and garlic are toxic in higher doses. 

All medications, whether natural or chemical, carry the risk of side effects. What is concerning is that these remedies have not, in most cases, been rigorously tested for safety. Many of them also do not come with instructions, which increases the risk of incorrect use. Natural does not always mean safe! Remember, cyanide is natural…

Websites promoting these natural remedies don’t have a responsibility to conduct scientific studies on these products or to collect data on safety and alert customers to any risks. Remember, just because a website has loads of good reviews, it doesn’t mean that they never receive negative reviews – they may just choose to hide those reviews from the public. 


So far, there seems to be no conclusive evidence that natural remedies work to treat or prevent fleas. There are also concerns about the safety of these remedies, which are largely untested and unregulated. Regular flea treatments work to break the flea cycle – meaning fleas are effectively and rapidly treated or prevented. If you are concerned about treating your pet for fleas you should speak to your vet who will be able to recommend a flea prevention protocol based on your lifestyle and needs as well as discussing any risks. Flea infestations can be difficult, time consuming and costly to treat. Although regular flea treatments can seem expensive, they are shown to be effective, and you may end up saving more money in the long-term. 

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