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The Irreverent Vet Speaks Out on Flea Collars for Cats

Petplace recently contacted me and asked me to write an article about this topic – Do Flea Collars Really Work on Cats?

First, let me introduce myself for those of you that don’t know me. I’m the Irreverent Veterinarian. I speak my mind and give you my honest opinion. I won’t sweet-talk you or sugarcoat the truth. I tell it like it is – to you, the drug companies, the pet product manufacturers, professional breeders and pet owners. Some might say that I’m truthful to a fault. Some of the pet owners and breeders who read my columns get really angry. It is hard hearing the truth.

So, do flea collars really work? This is an excellent question. I can’t speak for every veterinarian but I can speak for the majority. In fact, in preparation for this article I contacted 10 vets and asked for their opinions on this subject just to confirm my feelings on this subject. As it was – I was spot on in my thoughts.

This article refers to the generic flea collar you buy at the pet store. These comments do not refer to prescription flea collars you get from your veterinarian.

How Do Flea Collars Work?

There are many different brands of flea collars. Generally, flea collars work by either emitting a toxic gas to the local area (head/neck of the pet) or by exuding chemicals that are absorbed into the animal’s skin. Some flea collars have an Insect Growth Regulator (IGR), to prevent development of flea eggs and larvae.

One exception to this may be a flea collar produced by Bayer called Seresto. Bayer claims that “97% of veterinarians were stateside or very satisfied with Seresto for dogs or cats after 8 months.” None of the vets I interviewed for this article had personal experience with Seresto. If you are interested in this particular collar – please discuss with your veterinarian.

Do Flea Collars Work?

The answer is NO! Many flea collars are most effective in the local area (head and neck), which is little help since most fleas prefer the bottom or back end of the pet. Also, most flea collars aren’t strong enough to actually kill adult fleas.

Can Flea Collars Cause Harm to Cats?

Yes, flea collars can be harmful. Ingestion of collars can be toxic. The chemicals that are meant to be on the skin are absorbed into the body when ingested.

Cats can be particularly sensitive to some chemicals. NEVER use any flea product on your cat without the consent of your veterinarian.
Some flea collars can cause local irritation around the neck of the pet. This chemical irritation can be worse than the fleabites themselves.

How Do I Recommend Using Flea Collars on Cats?

Flea collars can be effective when used inside a vacuum canister. When fleas are vacuumed in, they are killed. They cannot escape from the vacuum and go back into your home. Cut a flea collar into pieces and place the pieces in the vacuum bag.

My Final Thoughts on Flea Collars on Cats

The most effective treatments are prescription medications from your veterinarian. They really work. I’m not getting one dime for giving you my honest opinion here, so if you could buy anything over the counter that worked as well I’d tell you.

Cat flea collars do little to kill fleas and some of the ingredients can be VERY toxic to some cats. To ready more about this awful toxicity, go to: Carbamate and Organophosphate Toxicity in Cats

There are safer and more effective alternatives to flea collars available on the market.

And because there are so many safe and effective products on the market, I don’t think it is worth using something that can be expensive and doesn’t work.

Here are two articles you can read for more information on treating fleas effectively. Go to:


The Irreverent Vet is a columnist that regularly contributes to The goal is to add a balanced and alternative view of some controversial pet issues. As happens with all of us, veterinarians can’t always say what they really think without offending some clients. This commentary allows vets to say what they think and gives you, the pet owner, the opportunity to consider another point of view. All opinions are those of the Irreverent Vet and not the views of and are not endorsed by