How do dog flea collars work? Your questions answered |

How do dog flea collars work?

Share on facebook
Share on pinterest
Share on twitter

Unassuming to look at, fleas can be a painful nuisance for our four-legged, furry friends. Aside from causing severe itching, skin problems and other infections, if left untreated fleas can cause your dog to become anaemic and even transmit tapeworms. And if that wasn’t enough to contend with, once they enter our homes they enjoy nothing more than a good carpet party, jumping around and indulging in a good feed of blood – including our own!!

Everything you need to know about how dog flea collars work

The easiest way to ensure that your dog remains flea-free is with regular flea treatments. One of the cheapest solutions available is to buy a flea collar. Worn around the dog’s neck they contain pesticides that get released into the dog’s hair and skin, killing fleas when they come into contact with it.

Having endured a lot of negative media recently; with France having banned them due to concerns over the chemicals they use and the EPA in America withdrawing the sale of collars containing the pesticide propoxur; I often get asked “how safe are dog flea collars” and “do they really work?”.

My personal opinion is that if you choose to use a dog flea collar that it should be for preventative purposes only and, like any toxic product, should be handled with care. Below, I will explain my reasoning why.

What is a dog flea?

Let’s start at the beginning. What is a flea and why does it cause so much pain for our pets?

The dog flea is particularly bothersome due to the diseases it spreads – in particular the cucumber or double-pore tapeworm.

Great athletes, fleas have the ability to jump to spectacular heights, seeking out new hosts to feed off or places to hide. Although they prefer the taste of dog blood, they are not adverse (if particularly hungry), to the odd bite of human. Feeding off a blood source gives the females the energy to produce anywhere up to 50 eggs a day, which they lay in the warmth of the dog’s fur. Taking just 2-3 weeks to grow to adult size, a persistent flea can live up to 2 years.

Great athletes, fleas have the ability to jump to spectacular heights, seeking out new hosts to feed off or places to hide. Although they prefer the taste of dog blood, they are not adverse (if particularly hungry), to the odd bite of human. Feeding off a blood source gives the females the energy to produce anywhere up to 50 eggs a day, which they lay in the warmth of the dog’s fur. Taking just 2-3 weeks to grow to adult size, a persistent flea can live up to 2 years.

How do I know if my dog has fleas?

You will know pretty quickly if your dog has fleas, as they will be constantly scratching and biting in order to relieve the pain of their inflamed skin. Fleas tend to reside in the head, neck and tail, so look out for loose hair and bald patches appearing.

Another sign is to stroke your dog’s hair backwards to expose the skin as you might catch a glimpse of them sucking for blood or see tiny dark specks of flea droppings.

If you start to itch or develop a small rash in places such as the elbow, knee or ankle then your home could be infested with fleas. Take a look through your carpet, rugs and soft furnishings as these are the areas they are most likely to live.

putting on a dog flea collar

How do flea collars work and are they safe?

A flea collar is generally made of plastic or leather and has a flexible buckle to clip around your dog’s neck. Over the years flea collars have taken a serious media bashing, but this is mainly due to the cheaper, older style versions which contain gasses and insecticides. These work by either releasing or absorbing chemical toxins into the dog’s skin and fur, in order to kill the fleas.

There are many flaws and risks to these collars, not least because the fleas need to venture near the neck for the most effective result. Many of these collars contain organophosphates – a pesticide used in agricultural products – that are thought to be dangerous, with some owners reporting toxic reactions in dogs, humans and other pets. Newer versions of the traditional flea collar are available by prescription from your vet and use both flea and tick repellent to tackle the problem.

There is, however, a more natural approach in the shape of a flea collar which is pesticide-free. Instead of chemicals, this flea collar relies on high-frequency sound in order to frighten the fleas away. I remain a little sceptical about this method, and wonder where in fact the fleas run to?

Should I use one?

A flea collar, in my humble opinion, is never going to free your pet of fleas completely. They only work on adult fleas and predominantly target the neck, face and shoulder area, leaving the hind legs and tails exposed. If you have children or pets in the house and a sensitive nose (the chemicals used are known to pong), I would consider looking at alternative flea treatment solutions for safety reasons.

Personally, I am not anti the idea of flea collars on a dog. If fitted in the correct way; so as not to irritate the dog or cause aggravation on application to human skin; it is a valid preventative method and provides peace of mind from fleas and ticks – especially if your dog enjoys being outdoors. I would always recommend that you consult with your vet first regarding which one to purchase.

Can any dog wear a flea collar?

I would strongly advise that you read the instructions for each individual flea collar. As a rule of thumb, flea collars are most effective for small or medium breeds of dogs, so if you have a large dog I would recommend a drop on treatment or a flea shampoo as trying to maintain them may become an issue.

If your dog is elderly, pregnant or nursing puppies then you would need to use alternative remedies (I have suggested some below), and for puppies, it is not recommended to use a flea collar until over the age of 6 months.

Credit: Pixabay

Are flea collars dangerous to humans?

If you are using a traditional flea collar that uses toxins, then most manufacturers will include a warning to avoid exposure to the skin and to wash your hands immediately after use. As the safety of these collars continues to be a hotly debated topic and evidence is still wildly conflicting, I would also recommend washing your hands after stroking or handling your pet.

If you have children in the house, I would advise against using flea collars altogether as a form of treatment, as the chemicals from the dog collar could potentially rub off on anything it comes into contact with.

Finally, steer clear of collars containing organophosphates and always consult your vet beforehand.

How long does a flea collar work?

The good thing about flea collars (yes they do have some positives over other types of remedies) is the longevity of the treatment. Whilst drop on solutions may only last for a few months, most collars will last for up to 8 months, and with some brands even claiming 12 months, it makes them great value for money.

What can I use instead of a flea collar?

Flea collars are not the only option available to dog owners to keep fleas away. I always recommend that you consult with your vet before treating your dog, but below I have compiled a list of the most popular flea remedies available today.

1. Drop On Medications

Often referred to as “drop on” or “spot-on”, these medicines are applied directly to your pet’s skin, and just like flea collars, contain ingredients that repel and kill fleas. Once applied either between the shoulder blade or at the base of the neck, the solution disperses the entire length of the dog’s body via the sweat glands of the skin.

2. Oral Medication

If you would prefer to give your dog medicine in an oral form, then there are options available. Normally given on a monthly basis, these tablets not only kill fleas and ticks but attack a multitude of other parasites. Although not the cheapest of options, this medication comes with very few reported side effects.

3. Sprays

Just like flea collars this is one of the most inexpensive flea treatments available and depending on the brand you use, can protect your dog from fleas for several months. One downfall with this product is that your dog must stay dry at all times, as failure to do this will result in it washing off. Easy to apply, you simply spray it directly onto your dog’s fur.

4. Powders

A flea powder treatment is good as it allows you to double-check that you have covered the entire body. You simply rub in a small dusting of the white stuff over your dog’s fur, including in between the toes.

5. Shampoos

Flea shampoo contains pesticides and is good for washing away both fleas and eggs and can last up to 28 days. Used just like a normal shampoo, it needs to stay on the dog for a few minutes before rinsing off.

6. Natural Flea Killer

When a more natural remedy is on offer, I do believe that it should always be considered as an alternative to chemicals. However, there are many old wives’ tales surrounding dog fleas and how to get rid of them. Although some might hold a grain of truth, most are unlikely to solve a flea infestation.

Common suggestions include:

  • bathing your dog in lemon juice or cider in the hope of drying out the fleas! It might make your dog smell nice, but it is unlikely to kill any fleas.
  • making your own flea trap using soap and warm water. This highly unlikely to work as there are no ingredients used here that would attract fleas to enter the dish.
  • sprinkling of salt onto carpets. This does in fact work as a dehydration agent and can kill fleas, but you will need to ensure that you vacuum your carpets persistently in order to see any real results.
  • potting plants such as chrysanthemums, lavender and spearmint. Has the potential to possibly work as some of these more natural ingredients can also be found in pesticides.
  • vacuum cleaning your house constantly. Unfortunately, a clean house does not necessarily mean a flea-free one, as fleas can move from host to host so can just as easily be bought in from outside.

    Credit: Pixabay


Dog flea collars are a relatively cheap alternative to other flea infestation treatments. Whilst they may provide your dog with longer protection, they should never be used to tackle an infestation and I firmly believe that collars should only be worn as a preventative flea solution.

So, if your nose can handle the smell and your dog isn’t irritated by them, upon consulting with your vet it could be a good flea remedy for your pet.

Please consider any toxic implications and ensure that you do not put yourself, your children or other pets at risk.

Share on facebook
Share on pinterest
Share on twitter
Mike Henderson
Mike Henderson

Mike (AKA 'Pest Control Mike') is a pest control operator from New York with over 15 years experience dealing with a wide range of pests. He shares his knowledge on this blog and provides useful information to help you combat pests on your own.

For severe infestations and professional advice you can also request a free pest control quote here.

Recent Posts
Scroll to Top
FREE Pest Control Quote
Before you go request a free pest control quote in your area! You will receive a call back from a pest control specialist.