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Can a Flea Collar Make a Cat Sick? Everything You Need to Know!

Flea collars are technically a type of medication, and just like any medication, they can potentially make a cat sick. Often, this occurs when a feline is allergic to the insecticide used in the flea collar. Cats could become allergic to the insecticide even if they responded fine to it before. Environmental factors and continuous exposure can cause allergic reactions in felines that weren’t previously allergic.

Therefore, a flea collar can make a cat sick. However, exactly how this occurs depends on the cat.

Flea collars can seem quite convenient but many of them do not work well. Many of the collars do not have proven ingredients that keep fleas away, and your results may vary. Furthermore, many contain strong pesticides that can be harmful to cats. They may cause skin reactions, such as a rash.

Therefore, many vets do not recommend flea collars.

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Potential Reactions to Flea Collars

Flea collars work by emitting chemicals that keep fleas away. However, these chemicals are also emitted into your pet’s face. Plus, they are also right up against your cat’s skin, which can cause more irritation. Therefore, while flea collars can be effective, they are not usually the safest option for your feline.

Reactions can vary. For instance, skin irritation can occur with any collar, and is a result of the collar rubbing on the skin. Making sure your cat’s collar fits properly can help ensure it doesn’t move too much.

However, collars can also cause chemical burns on your pets. Other side effects include seizures and serious neurological symptoms. Sometimes, these symptoms can even be deadly. Some cats may react fine to the chemicals in the collar while others may react very negatively. A quick look at any major review website will show you countless negative reviews that involve serious side effects.

Many vets do not recommend flea collars because they may cause side effects like these. While treatment can help many cats, neurological symptoms may hang around even after discontinued use.

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

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Alternatives to Flea Collars

We recommend using an alternative to a flea collar. It’s still important to protect your cat from fleas, so don’t let flea collars prevent you from using any form of protection. Instead, we recommend using one of the safer methods below.

Topical Applicators

Out of all the options out there, we recommend topical applicators first and foremost. These are often easy to apply and effective. You do have to reapply them on a schedule, however, many products only need to be applied monthly or every three months. Most are waterproof so you don’t have to worry about your cat getting wet.

Of course, not all topical applicators are effective. Most have an adulticide ingredient, which kills adult fleas. This usually remains effective between doses, preventing fleas the whole time. Others include insect growth regulators, which prevent larval fleas from maturing. Those with this ingredient are most effective, as they prevent fleas from maturing while on your feline.


There are many anti-parasite medications out there that are also effective. These kill fleas when they bite your feline. While this does mean that your feline has to be bitten, they are more effective than most other options out there. Plus, many prevent all sorts of parasites, including worms and ticks. Therefore, if you’re looking for all-around protection, this option is the best.

Of course, medication can be a bit more difficult to give to your feline. However, many owners find wrapping the pill in cheese or cat-safe meat is effective. It depends mostly on your cat. Some felines are so picky that they’ll catch on to the charade and refuse to eat these special treats. Others will eat the treat and spit out the pill, so be sure to watch your cat while they’re eating.

Most of these medications need to be readministered monthly or every few months.

british short hair cat wearing flea collar
Image Credit: Georgy Dzyura, Shutterstock

Cat-Safe Flea Treatments for the Home

Often, when cats get fleas, the fleas will be elsewhere in your home as well. Therefore, we recommend treating your home, as well as your cat. When using a flea-collar alternative, consider using a method that kills fleas in your home, too.

There are several sprays and treatments to kill fleas in your home.

These usually fall into a few different categories:
  • Adulticide treatments that only kill adult fleas
  • Professional treatments applied by a pest control company
  • IGR sprays that prevent fleas from maturing

For most flea treatments, an adulticide and IGR spray are helpful. Adulticide-only sprays can be used, but you’ll have to reapply them regularly to keep killing adult fleas. There is always a chance that the fleas will reproduce before you spray them, and then their eggs will hatch and mature. Therefore, you’ll have to keep spraying until all fleas are eliminated.

IGR sprays often only need to be used once, as they prevent fleas from maturing. Of course, having an adulticide is also vital, as you’ll also want to kill the fleas that have already matured.

Be sure to spray everywhere. Remove cushions and spray them. Get underneath the bed. Lift rugs. Pillows and blankets can be washed in a washing machine to kill fleas and eggs (assuming it is safe for them to be washed, of course).

Be sure to get your cat’s bedding very well, as this is where most fleas will live. After vacuuming, spray the inside of your vacuum bag, as eggs and larvae can develop inside it. Vacuuming before using the spray can be helpful, as it can encourage flea eggs to “hatch.”

Read All Labels Carefully

Cats are often more sensitive to chemicals than dogs. Therefore, they tend to react negatively to chemicals that dogs might be fine with. Flea-prevention products labeled for dogs may not be safe for cats—check the label on all products and ensure it is made for cats and not dogs.

Products labeled for both cats and dogs are typically safe. Often, these include cat-safe ingredients, which are usually safe for dogs, too. When in doubt, ask your veterinarian.

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While we recommend that all cats are given a flea-prevention treatment, flea collars are probably not the best option. These are often not very effective. Furthermore, they can cause side effects, including seizures and they are often not recommended by most vets.

Instead, a topical or oral option is often best. Both of these are pretty easy to apply and can be effective. Of course, different treatment options have different effectiveness and safety so be sure to research any product before purchasing it.

Related Read: Can You Use Dog Flea Collars on Cats? (Vet Answer)

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Featured Image Credit: Fayzulin Serg, Shutterstock