How Long Does It Take For A Flea Collar To Work

How Long Does It Take For A Flea Collar To Work

I doubt there’s a pet owner anywhere in the world that isn’t aware pets get fleas. No matter how careful you are, it’s a fact of life, it happens. Still, we don’t want them in the yard, inside the house, in carpets and furnishings. They bite, they draw blood, and they irritate. Also, once infected, you have the devil of a job getting rid of them. When alive they lay millions of eggs, so you kill the live ones and then eggs hatch and back to square one.

Pet owners are constantly on the lookout for the best method of killing fleas. One such method is the flea collar. Pet owners ask 3 typical questions. Are flea collars effective? How long does it take for a flea collar to work? And will a flea collar harm my pet?

In this article, we will answer all 3 of those questions and give you some more information about flea collars that you might not have thought about.

Why You Need To Eradicate Fleas From Your Dog

Fleas are an efficient life-form. They feed and within 48 hours lay their eggs, and they lay up to 50 eggs each day. They lay their eggs on the animal and the eggs drop off the dog wherever he visits in the home. Carpets, pet bedding (your bedding), furniture, and in the yard.

In the pupa stage, they can live for up to 2 years before hatching. Then it starts again.

From a health standpoint a specific tapeworm Dipylidium caninum uses fleas as an intermediary host, your dog accidentally ingests the flea and they now have tapeworms. They have even infected humans. Fleas don’t live on humans, but they bite and feed, as we mentioned.

The saliva from fleas is also toxic. In fact, the most common skin allergy found in pets is flea allergy dermatitis.

How Do Flea Collars Work?

There are two flea collar designs.

They design the first type to repel fleas. These collars give off a chemical substance. Their aim is to stop fleas and ticks from landing on your pet.

Happy dog with flea collar

The second collar design has two options available. One, it allows medication in the collar to enter the fatty layers of skin on your dog, which then spreads over his body. This is poisonous to the flea, so when it bites your dog it will die.

Two, it releases an ingredient that kills the flea on contact, thus never giving the flea the opportunity to bite.

Depending on which type you prefer, be careful to double-check the box.

Are Flea Collars Effective?

If you are dealing with a flea issue inside the home a good tip is to place a “killing type” of collar inside your vacuum. That will kill the larvae and any live fleas you vacuum up.

There are various chemicals used to create an effective flea collar. Some of which are toxic to humans. It’s definitely essential to read thoroughly the instructions on the box. Wash hands for a full minute when you have been handling a flea collar. I realize it’s difficult to control, but children shouldn’t be touching dog collars.

Something to think about if you intend to use flea collars. A report by the NRDC (Natural Resources Defense Council) found “high levels of pesticide residue can remain on a dog’s or cat’s fur for weeks after a flea collar is put on an animal”.

The report went even further by stating “Residue levels produced by some flea collars are so high that they pose a risk of cancer and damage to the neurological system of children up to 1,000 times higher than the EPA’s acceptable levels,”.

So the quick answer is this. Flea collars are effective in killing fleas, but at what cost to the pet and its human family?

Benefits of Flea Collars


  • A flea collar is very convenient. No tablets or sticky, smelly chemicals to apply. If the dog is used to a collar, then they’re ready.
  • They are cost effective. Much cheaper than other medications.
  • Depending on the collar type they can be long lasting, some collars will continuously work up to 8 months. Unlike the oral or spot-on type, which might need replenishing every 30 days.


  • Not recommended with young children around. They inadvertently touch the collar and put their fingers in their mouths. This is highly dangerous for children because it exposes them to very harmful chemicals.
  • Collars are at their strongest where they are situated. Around the neck. Not much of an issue for small dogs, but big dogs cannot achieve the same level of coverage. So it could leave half the dog unprotected. Leaving you to top-up with drops or oral medicine.
  • This begs the question could you be over-dosing your dog with these chemicals?

How Long Does It Take For A Flea Collar To Work?

Depending on the chemicals used for the pet flea collar within 24 hours. Then any fleas attempting to re-infest will be dead within 2 hours. Your pet should be totally flea-free within 2 weeks. They design some collars to release the active ingredients slowly up to 8 months.

How long does it take for a flea collar to work

For a flea collar to be effective, it must be the correct length. It needs to fit snugly but not inhibit breathing or movement. Pet parents of smaller dogs might need to cut the collar down to size. Don’t leave any extra length the dog can chew on. This is toxic and will impair your dog’s health.

Are Flea Collars Right For Your Pet And Family Situation?

Dog owners have their own reasons for choosing flea collars. Some of these reasons may be along these lines:

  • They are convenient and easy to deal with.
  • No time wasted waiting for the chemicals to dry.
  • Cheap compared to oral and spot-on methods of flea control.

Flea collars that have a long life-span are easy to manage for owners that frequently forget the monthly or bi-monthly flea treatments. They are also useful if you take your dog hikes into territory known to be the habitat of fleas and ticks, as a top-up solution just for the day.