Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How Do Flea Collars Work for Cats? (The Surprising Details)

british short hair cat wearing flea collar

Few parts of cat ownership are as troublesome (and itchy) as dealing with a flea infestation. Once fleas take up residence in your home and on your cat, getting rid of them can be time-consuming and expensive.

Cat owners can choose between multiple types of flea control at various price points. One well-known form of flea control is a flea collar. In this article, we’ll cover how flea collars work for cats, including the advantages and disadvantages of using them. Generally, flea collars have pesticides that will kill the fleas.

divider single cat paw oct 2024

How Do Flea Collars Work?

Flea collars are placed around your cat’s neck and replaced after a specific period, anywhere from 1–8 months. The collars contain pesticides designed to kill and prevent fleas. Several chemicals may be used, depending on the product.

Flea-killing chemicals are generally neurotoxic and kill by impacting the insect’s nervous system. Some flea collars target adult fleas only, while others attack the flea larva by preventing them from developing into adults.

The chemicals from flea collars are generally spread across the cat in two ways. Some flea collars give off a toxic gas that keeps fleas away. With others, the chemicals are absorbed into the cat’s skin and spread that way.

Collar for animals protecting against fleas
Image Credit: Gagarin Iurii, Shutterstock

What Are the Different Types of Flea Collars?

The main differences in types of flea collars are what kind of chemical is used, how long they last, and where they are purchased.

As we mentioned, flea collars may contain chemicals that kill adult fleas only or keep flea larvae from maturing. The most effective types will contain both products.

Here are some common active ingredients you may see in flea collars:
  • Imidacloprid
  • Flumethrin
  • Deltamethrin
  • Amitraz
  • Tetrachlorvinphos

Flea collars become less effective over time and must be replaced. Every flea collar differs in the length of time they work. You can expect long-lasting collars to be more expensive as a one-time purchase, but they may be more cost-effective when you factor in how often cheaper collars are replaced.

Flea collars are usually one of the easiest parasite-prevention products to buy. Several brands are commonly available over the counter at retail stores, including pet retailers. Your vet may also carry one or more types of flea collars.

Veterinary-specific flea collars typically require a prescription and are often more expensive than those you buy at the grocery store. The catch is that cheaper flea collars are notoriously ineffective. There’s no point in saving money if the flea collar does not work and you and your cat are both still scratching.

Where Are Flea Collars Used?

Flea collars are used anywhere your cat is at risk of a flea infestation. Opportunistic fleas thrive in indoor environments, such as heating ducts. Even if your cat never sets foot outdoors, it could still get fleas.

Because they are one of the cheapest forms of flea control, flea collars are often used for outdoor-only cats to provide some protection against parasites. Some owners prefer them because they’re easy to put on and not as messy as spot-on flea preventatives.

In most cases, flea collars (or other flea control) should be used year-round. Even when it gets cold enough to kill fleas outside, they can still live inside.

White cat wearing a green collar from fleas and ticks
Image Credit: Inga Gedrovicha, Shutterstock

divider single cat paw oct 2024

Advantages of Flea Collars for Cats

One advantage of flea collars is that they are easy to use.  You simply put the collar on your cat and tighten it as directed. Another advantage is that they don’t leave residue on the cat’s skin and coat like flea sprays or spot-on treatments.

Cat owners with children or other pets may worry about them touching the spot-on flea treatments and prefer a flea collar. Flea collars provide longer-lasting protection than bathing in flea shampoo. They’re often cheaper than other flea control products, too.

Disadvantages of Flea Collars for Cats

The most significant disadvantage of flea collars is that many don’t work well. The effective ones tend to be the most expensive, which eliminates one of the advantages of this type of flea control.

Another disadvantage is that some cats won’t wear a collar, and there’s some risk involved when they do. Determined cats can kick or wiggle their way out of a flea collar. Flea collars usually don’t come with a breakaway option, which means they could snag and choke or trap your cat. Or get a limb trapped in the collar, causing severe injury to associated tissues.

Some flea collars are irritating to a cat’s skin and may also irritate humans who touch them. Most are also toxic if ingested, which can be dangerous for small children or curious dogs.

kitten wearing green flea collar
Image Credit: Fayzulin Serg, Shutterstock

divider single cat paw oct 2024

Frequently Asked Questions (FAQ)

How Tight Should the Flea Collar Be?

Follow the directions for your specific collar. Generally, the collar needs to be tight enough to contact the skin while still allowing you to slip two fingers in between. If the collar is placed too loosely, it can easily be pulled off by your cat. Check the collar frequently to ensure it’s not getting too tight.

My Cat Is Wearing a Flea Collar. Why Do They Still Have Fleas?

Check to ensure your cat’s collar fits correctly and isn’t out-of-date. Most importantly, ensure you’re treating the cat’s environment for fleas and using preventative products on your kitty. Fleas will continue to hatch, grow, and find their way to your cat unless you remove every part of its life cycle from your cat’s environment. Adult fleas are generally vulnerable to pesticides, but eggs and larvae are not.

You can treat your house with a spray to kill fleas or stop larvae from developing, and professional pest control companies can help. Vacuuming frequently and disposing of the vacuum bag promptly will reduce the population in your home.

You can also replace your cat’s bedding and stuffed toys or wash them in hot water. If your cat goes outside, you’ll need to treat your yard too.

What Other Types of Flea Control Are Available?

Flea shampoos and flea sprays are available at your vet’s office, pet stores, and online retailers. Flea shampoos only kill the fleas on the cat at the time and don’t keep new ones from jumping on. Plus, you’ll have to bathe your cat.

Flea sprays can be effective, but applying them can be a challenge. It can take the cat a while to dry, too. However, the two types of flea control that are generally easiest and most effective are oral or spot-on treatments.

Flea preventatives in pill form eliminate any worry about smearing chemical flea products in the house. They’re cleaner and less worrisome. However, you have to get a pill into your cat once a month, which is challenging with most felines.

Spot-on flea treatments generally come in a pre-measured tube that’s squeezed onto the cat’s skin, usually on the back of its head. The product spreads using the cat’s natural oils. Many are combination products that also prevent ticks, heartworms, and even some intestinal worms.

divider single cat paw oct 2024

Conclusion

Effective flea control is a must for cat owners. These insects are not just itchy pests; they can also carry diseases and other parasites. While some flea collars may be effective, they usually aren’t the recommended form of flea control. No matter which type of flea prevention you choose, follow the directions for application carefully for the best results. Never use a dog flea product on your cat, even if they’re the size of a small dog!


Featured Image Credit: Georgy Dzyura, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Petsies Custom Pajamas Review 2025: Our Expert’s Opinion

What Are Petsies Custom Pajamas? How Does It Work? Petsies is the sister company of Budsies, a Florida-based business focusing on custom gifts...

Kucing Malaysia: Breed Info, Pictures, Care & Characteristics

The Kucing Malaysia is a relatively new breed of cat, having only been first bred in the 1990s. It is the first Malaysian...

How Many Hours Does a Cat Sleep? Vet-Reviewed Facts & FAQ

If it seems like your cat sleeps a lot, it’s probably because it’s true. Cats love nothing more than having a few cat...

Feline Distemper: Signs, Causes, and Care (Vet Answer)

Distemper in cats is also called feline panleukopenia, so we will use the terms interchangeably in this article. It is a viral disease...

More related

Should Cats Stay in the Cabin or Cargo of Planes? My Preference for Olga

Hi, I’m Christopher! Read my introduction to learn more about me and my silly Russian Blue cat, Olga. Flying the friendly skies is...

Cats Back to School Blues: 6 Ways to Prep Your Cat

Cat owners get the chance to spend lots of time with their buddies during summer vacation, which most cats absolutely love and quickly...

How My Cat Helped Me Find Love: Dr. Karyn’s Valentine

Hi, I’m Dr. Karyn! Read my introduction to learn more about me and meet my five hilarious cats: Clutch, Cyril, Alex, Zelda, and...

How Much Does a UK Pet Passport Cost in 2025? Requirements & Breakdown

If you’re planning a trip abroad and bringing your pets, you must ensure you have all your documents in order. Between 2000 and...

Keep reading

Does CBD Oil Help Cats with Kidney Disease? Vet-Reviewed Facts & FAQ

Cat’s kidneys play a crucial role in their overall health. If your feline’s kidneys are not functioning properly for whatever reason, the resulting problems can be life-threatening, impacting their well-being and quality of life. Chronic kidney disease, or CKD, is...

giving cat cbd oil

Can Cats Be Hermaphrodites? Vet-Approved Feline Facts

Cat lovers who spend a lot of their time learning about their feline friends have probably heard tales of hermaphrodite cats that have male and female sex organs. But is it possible for cats to be hermaphrodites? Cats can be...

close up bronze Egyptian Mau cat

Are Laser Pointers Bad for Cats? Vet-Approved Safety Information & Tips

Laser pointers are popular toys, and it can be fun watching your cat chase after that little red dot. But if you’re wondering whether laser pointers are safe for cats, the short answer is that laser pointers are controversial because...

Two cats are lying on the floor. Gray cats are playing with a laser pointer.

Why Did My Cat Pee on Me While I Was Sleeping? 5 Vet-Reviewed Reasons

Are you Googling question this while you’re washing your sheets? If your cat peed on you while you were sleeping, you want answers! After all, you’ll want to ensure the situation doesn’t repeat itself. So naturally, you want to get...

Cute cat sitting near wet or piss spot on the bed in the bedroom

Is Catnip Safe for Kittens? Vet-Reviewed Facts & FAQ

In a way, catnip is as much a treat for doting pet parents as it is for their feline family members. We may not get the same euphoric benefits, but it feels good to know we can offer an extra-satisfying...

Catster_Is Catnip Safe for Kittens

What to Do When Your Cat Has an Asthma Attack: Vet Approved Tips

It may be a surprise to learn that just like people, cats can have asthma, and it can be a frightening experience when your cat suddenly suffers from an asthma attack. While it’s a condition that your cat will have...

a cat that feels sick and seems to vomit

Why Does My Cat Bite My Nose? 6 Possible Reasons & Vet-Approved Tips

Our cats communicate with us in all sorts of ways. Some ways are comical, others are challenging, and still others are second nature and expected. However, what if your cat has an odd quirk and the message is unclear? If...

Female hugging her cute long hair kitty

9 Best Dematting Tools for Cats in 2025 – Reviews & Top Picks

Keeping your feline healthy and happy is your top priority, but are you brushing your cat’s hair every week? Cat owners often disregard grooming duties because cats seem to take care of themselves pretty well. Cats are methodical about cleaning...

hand holding shedded cat hair