Are Dog Flea Collars Safe? (For Dogs & Humans)

Are dog flea collars safe

In modern society, we have become accustomed to living with flea-free dogs thanks to commercially available tick and flea remedies including flea collars. But this convenience can have hidden dangers.

A recently published article by the NRDC (Natural Resources Defense Council) warned that flea collars are toxic to dogs and can also harm humans. Here’s a brief synopsis of what was said, followed by why and what you can do to make your dog safe.

Are flea collars safe for dogs? Research shows that flea collars are not safe for dogs. In 2021 a report revealed how 1,700 pets had died from exposure to toxic chemicals in Seresto flea collars. Some pet stores have now stopped selling toxic dog flea collars containing the dangerous pesticide tetrachlorvinphos.

Scary stuff I am sure you would agree. But just what is the truth behind the recent warnings that dog flea collars are not safe for your pet, and potentially owners including toddlers?

Here’s all you need to know on whether dog flea collars are safe to use on your dog currently.

Are flea collars safe for dogs and puppies?

Millions of dog flea collars have been sold globally, but recent studies have shown that, due to their potent and poisonous ingredients, they are not harmless. In fact, flea collars are not safe for dogs and are toxic.

In addition, there are dangers associated with pets wearing collars, of any form, while unsupervised – for example, dogs should not wear collars in their crates due to strangulation risks.

Why flea collars are toxic to dogs

Despite the active ingredients not being absorbed by the sweat glands, some dogs will experience skin irritation and even burns. The mechanism that dries out insect exoskeletons can also dry out your dog’s skin.

This will cause them to scratch their necks or to chew other parts of their bodies out of frustration at the pain.

Studies showed that a toxic powdery residue, from the collars, remains in the dog’s fur for a considerable period after application. This residue can make its way onto the dog’s bedding, carpets, furniture, and any other places where the dog spends time.

Digestive problems can also result from ingesting the powder, possibly by chewing on themselves or toys and treats, that lie in contaminated surfaces. These problems could manifest themselves as a loss of appetite, drooling, vomiting or diarrhea.

In worst case scenarios, the toxins can make their way into the kidneys and cause renal failure and other metabolic problems. Based on this, flea collars are toxic, and not safe.

If the fine powder becomes airborne and is taken in through the dog’s airways, the powder could cause breathing difficulties and possible lung damage.

If the active ingredients start to affect the nervous system, your dog could develop issues related to balance. If your pet starts walking erratically or experiencing nausea, these are reasons for concern. Even more serious symptoms include tremors and seizures.

Sadly, in recent years, reports have indicated that there have been more than 75,000 negative incident reports associated with the use of flea collars, 2,500 of which ended in fatalities.

An article in USA Today reported the following:

“Since Seresto flea and tick collars were introduced in 2012, the EPA has received incident reports of at least 1,698 related pet deaths. Overall, through June 2020, the agency has received more than 75,000 incident reports related to the collars, including nearly 1,000 involving human harm.” 

Are flea collars safe for small dogs?

Smaller dogs are at more risk of the chemicals in flea collars due to their size. It makes sense that a larger dog will be more resilient against toxic chemicals than a smaller one.

It’s also a consideration when you have two dogs. If they regularly indulge in play fighting, they will inevitably attack the neck area and ingest some of the toxins from the flea collar.

Are flea collars safe for puppies?

Flea collars are not safe for puppies either. Puppies may bite off bits of the collar and swallow them whole. This represents a danger, regardless of toxins.

If your dogs and other pets share bedding and favourite resting spots, they are open to the same dangers affecting the dog that is wearing the collar. Cats could develop any of the problems that afflict dogs but are at additional peril if the flea collar is not suitable for use on felines.

Cats and dogs that are on friendly terms could present additional problems if the cats routinely groom the dogs. Through their licking they will absorb the toxins which could result in any of the digestive or neurological problems described above.

How to keep your dog safe from a flea collar

Flea collars are said to be effective against ticks and fleas for months after they have been applied. They usually come sealed in aluminium foil, with a warning to keep the collars away from food, and to wash your hands thoroughly after touching them.

There should be clear indications on the package that they are suitable for dogs or cats or both. Cats cannot be regarded as small dogs when purchasing flea remedies. Products containing permethrin should never be used on cats.

If you plan to use a flea collar on other animals, such as kit foxes or ferrets, consult your veterinarian before doing so.

Handy Hint: Here’s how to get rid of fleas on very young puppies.

It is advisable to purchase all your flea and tick remedies from a veterinary clinic or store. Pirate copies, as well as dubious brands that have not passed safety standards, can be found at more generalised outlets.

If your animal is to be unsupervised for long periods of time, it is advisable to remove all collars. They should not be worn when the animal is in a crate, sleeping or at the groomers.

Taking a flea collar off repeatedly under these circumstances, reduces its convenience.

How flea collars work

When you see how they work, it soon becomes clear why flea collars are not safe for dogs. The active ingredients in most flea collars are neurotransmitters and insecticides. They work in concert to dehydrate the exoskeleton of the fleas and gain access to their nervous systems.

The aim is to kill the parasites and thereby prevent reproduction.

Seven active ingredients, that were routinely used in the manufacturing process of flea collars, have either been banned or have voluntarily ceased to be used in production.

Others are still under review.

The powder containing the active ingredients is sloughed off the dog’s flea collar over time, and makes its way via your dog’s oil glands into its bloodstream. Dogs do not have sweat glands in their neck area, so theoretically the toxins are not absorbed by the skin.

Fleas and ticks feed off your pet’s blood. When they ingest the blood, from a dog wearing a flea collar, they absorb the toxins along with it and are destroyed.

Are flea collars safe around toddlers and babies?

No, I don’t believe that dog flea collars are safe around toddlers and babies. Just by touching them, it’s possible to transfer dangerous toxins to the body through the skin. And if you think how toddlers interact with pet dogs, you can see how this risk is amplified.

Many of us treat our pets more like family members than animals. We cuddle them and otherwise come into close contact with them. Toddlers and older children indulge in frequent physical displays of affection with their pets.

The NaturePedic website blogged about this, and wrote:

“The offending toxic chemical, Propoxur, is classified as a human carcinogen and is toxic to the human nervous system. In California – where flea collars containing Propoxur must have a warning on the label – Propoxur is classified as a cancer-causing agent by the state’s Safe Drinking Water and Toxic Enforcement Act.”

Pregnant women and toddlers are susceptible to the effects of the potential toxicity associated with dog flea collars. The neurotoxins can adversely affect the underdeveloped brains of the unborn and very young children.

Among the incident reports, some people have complained of rashes and hives after handling dogs that were wearing flea collars.

The bottom line: dog flea collars are not safe for young children if they have the toxic ingredients in them.

Should dogs wear flea collars?

Based on what we now know, plus the risks of dogs of strangulation when wearing a collar, I don’t believe that dogs should wear flea collars.

There are alternatives to flea collars that are safer for dogs.

Flea and tick preventatives are also available in the form of pills and topical applications.

For example, here’s are flea remedy pills on Amazon.

The spray on application uses the same active ingredients as a flea collar and is subject to similar precautionary measures. This will have the advantage of drying quickly and not leaving a powdery residue.

As with before, you can buy the flea spray on Amazon by clicking the image below.

Your dogs could experience a measure of discomfort though. My dogs tend to disappear when I bring out the vials. Either, the smell is a deterrent, or the application irritates their skin for a short while.

It is not advised to come into close physical contact with the dog for a day or two after application. The dog should also not swim, be bathed, or spend time out in the rain until the active ingredients have been absorbed into the bloodstream.

You might find your dog acts a bit weird after being sprayed or ingesting flea treatment.

You could consider natural remedies for dog fleas.

You can create your own flea powder deterrent, using diatomaceous earth. It has a similar desiccating effect on fleas.

Bath your dog and comb it with a flea comb to ascertain if your dog has a flea infestation.

Apply diatomaceous earth liberally, but carefully, on the dog’s back and comb it into the fur. It comes in the form of a fine powder so be careful not to breathe it in or create clouds of dust.

Identify any potential cracks and crevices in your home that could serve as a base for the fleas. Sprinkle the diatomaceous earth in these areas. You will need to monitor the situation for progress in eradicating the pests. Vacuum and reapply the powder regularly until there are no more fleas.

If you would prefer a liquid solution, make a tea of witch hazel, aloe vera juice, lavender oil, cedar wood oil, and lemon in the form of juice or essential oil. The first two ingredients are gentle on the skin and have anti-inflammatory properties. The rest repel insects.

You can use this tea in the form of a spray, which you apply round your dog’s neck and ankles, or you could soak a bandanna in the solution and hang it around your dog’s neck.

This remedy can be made and applied on an as needed basis, as it does not last as long as the chemical alternatives.

It is safe for humans to use, and it is recommended that you spray it around your ankles before walking through tick infested areas.

What to do if your dog was poisoned by a flea collar or treatment

Take immediate action as dog flea collars can be toxic.

If you suspect that your dog’s flea collar is causing your dog any of the problems I’ve discussed, remove it immediately and dispose of it safely.

Wash the dog with a gentle pet shampoo, in a generous amount of water. Rinse the shampoo and any residue from the collar off thoroughly.

If the problems are serious or persist after the bath, consult your veterinarian as soon as possible.

Monitor other pets in the household as well as children and adults for any unusual signs of distress.


If you have pets, there will always be parasites lurking nearby, intent on setting up home and making a living off them. Most of these parasites do not confine themselves to your pets.

They will come after you.

It’s no wonder then that millions of dog owners put flea collars on their pets.

However, given the recent research into the dangers and risks, it’s clear that dog flea collars are not safe.

Until that changes, I won’t be using them on my dogs.

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Marc Aaron

I write about the things we've learned about owning dogs, the adventures we have, and any advice and tips we've picked up along the way.

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