Do Flea Collars Work?

Anyone with a dog or cat faces the constant fear that their pet will develop a flea infestation sooner or later. Luckily, there are a variety of flea controls products for cats and dogs. Flea collars are one of these products, and they can be used on pets for both flea prevention and treatment.

In this article will we discuss how flea collars work for both cats and dogs, if they actually work to remove fleas, and if they are safe to use.

do flea collars workAdams Flea Collars

In this article we will focus on Adams flea collars. Keep in mind though, there are a variety of other flea collars on the market, from many different manufacturers. They do not all work in the same way. You can even find some electronic flea collars, but we won’t be covering those here.

How Flea Collars Work

Adams flea collars come in a few different varieties. Obviously they have different collars for cats and dogs, and different sizes depending on how large your pet is. More importantly though are the active ingredients used in these collars. Here are the active ingredients in Adams flea collars, and how they work:


What is it?
Methoprene is an active ingredient you will find in all of the Adams flea collars, both for cats and dogs. This chemical is a juvenile hormone (JH). This does not kill adult fleas, but instead works on the larvae that could be on your pet’s body. It is growth regulator, meaning that the flea larvae will never be able to pupate into adults. Methoprene will interrupt the life cycle of fleas, so new no adults can continue the infestation.

Is it safe?
Methoprene is classified as “very low in toxicity”, and is almost non-toxic to humans and pets. It is only mildly toxic when absorbed through skin. It is even used in the production of foods such as mushrooms, meat, and milk.


What is it?
Propoxur is a carbamate insecticide that kills adult fleas, and is used in collars for both cats and dogs. It works by shutting down essential neurological enzymes. It takes effect very quickly by paralyzing the adult fleas’ nervous systems. Propoxur also has a long lasting residual effect, which is why it works so well for flea collars.

Is it safe?
Propoxur is toxic in large concentrated doses to both humans and pets. However, in the concentration and amount used on flea collars, it should be safe. You can learn more about health concerns with propoxur here.


What is it?
Tetrachlorvinphos is another insecticide that kills adult fleas, but is an organophosphate. It works like Propoxur, harming the nervous system in the same way. However, the damage is irreversible. This ingredient is not used in cat collars, and only in the longer lasting collars for dogs. (The collars that use this ingredient will not be mentioned anymore in this article.)

Is it safe?
It is believed to be a human carcinogen, and is toxic to our nervous systems. In large doses it can kill dogs and cats, sometimes even humans. Even in lower doses it can result in signs of poisoning. You can read more about the toxicity of tetrachlorvinphos here.

Buy Flea Collars

flea collar for dogs

flea collar for cats

The Bottom Line

Flea collars do work, but they are more toxic and dangerous than other flea control methods for pets. Some people also claim that the collars only work for fleas around your pet’s head. So your pet might still get fleas around their rear-end and tail, even while using a flea collar. You will probably want to use other flea control methods before trying flea collars.
Read about other flea control for dogs →
Read about other flea control for cats →

Related posts:

  1. Do Flea Traps Work?
  2. Flea Drops for Cats
  3. Flea Shampoo for Dogs
  4. Flea Spray for Dogs
  5. Oral Flea Medication