Reasons Why My Cat Still Has Fleas After Treatment

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Cats, like other pets, often struggle with flea infestations. As a result of their persistence, they may cause frustration for pet owners.

Moreover, many pet parents are surprised to find that their cats still have fleas after treatment, prompting them to ask why their cat still has fleas after treatment.

Well, you’ll discover the answers to this in the following sections!

How does the flea life cycle work?

After a cat has been treated for fleas, some people may still find their pet scratching at fleas. This is largely due to the life cycle of a flea which is quite complex.

my cat still has fleas after treatment

Basically, fleas go through four stages: egg, larva, pupa, and adult. Eggs are laid on the host animal, such as your feline companion, where they hatch into larvae.

The larvae feed on organic matter, including dried blood, feces, or dead skin cells. Once they have had their fill, they spin a cocoon and become a pupa.

The pupa can remain in this stage for weeks, months, or even years until it is triggered to become an adult flea. The adult flea then jumps onto a host and begins the cycle anew.

What’s more, the life cycle of a flea is a continuous process, and it can be activated all over again when an adult mates and lays eggs.

Therefore, since the flea life cycle is long, continuous, and can take several weeks to complete, even if you treat your cat for fleas, there is still a good chance that you will see them again in the future.

How does the flea lifecycle impact Your cats?

A big and furry kitty trying to scratch her ear with her back paw.

Fleas can be a major nuisance for both pet parents and their adoring cats. They can cause skin irritation and hair loss, and they can also transmit diseases.

Treatment is essential to get rid of fleas, but in order to completely exterminate fleas from your environment, you must take into account the lifecycle of a flea.

The cocoon stage is immune to most insecticides and can survive for 12 weeks or more if conditions aren’t right. Make sure you treat all areas where your cat frequents and repeat the treatment cycle every few weeks to ensure that any new fleas that hatch are also killed.

In fact, if you break your cat’s treatment program by forgetting a dose or not treating all the animals in your household, the pupae can hatch, lay eggs, and start the cycle all over again.

Reasons why my cat still has fleas after treatment

cat with bold patches, skin condition caused by lice, fleas or allergy

Fleas are incredibly annoying and notorious pests, but flea treatments are as widespread. Despite this, pet owners often ask, why my cat still has fleas after treatment?

If you are on the same track, the following part will clear things out for you.

Incorrect Application of Product

One of the most common reasons for the re-infestation of fleas in cats right after treatment can be the incorrect application of different products. This often results from a lack of proper application knowledge, careless administration, and supervision.

Let me explain.

Take, for example, the flea treatment, which is often executed the wrong way. These treatments, whether over the counter or prescription, must be applied directly to the cat’s skin in order to be effective.

Applying the treatment to its hair will not work and could cause health problems for your cat.

Another example may include improper supervision. When using an oral flea medication, it is important to monitor the cat closely.

If it does not consume the entire dose, then there is a risk that some of the fleas will survive and reproduce. This can lead to a re-infestation of the home and yard.

Bathing your cat too soon

It is often recommended to bathe your cat after applying flea medication. This is because the soap and water can help remove any residual product from the fur and also help to kill any fleas that may have survived the treatment.

However, while it is important to clean your cat after a flea infestation, you should wait until the treatment has had time to work before bathing your cat.

Bathing your cat too soon can remove the medication and cause the fleas to come back.

Not treating the house.

Another reason your cat is continuously reinfected is the exclusion of treating the environment they live in.

If you are only treating your cat and not the house, you are likely not getting rid of all of the fleas.

Flea eggs and larvae can live in carpets, furniture, and other areas for weeks or even months after treatment. It is important to use a product that will kill both the adults and the eggs/larvae in order to completely get rid of the fleas.

This will prevent your feline friend from contracting pesky fleas even after treatment.

Not Treating All Your Pets

If you have more than one pet and just medicate the one that is scratching or biting for fleas, be prepared for a re-infestation.

I made the same mistake. Of the three pets I own, I only got my cat medicated later to find all my pets infected with fleas.

Remember, just because you can’t see fleas on all of your pets doesn’t mean they don’t exist! Even if just one person is afflicted, the illness has spread like wildfire.

Therefore, treating only some of the animals in your house for fleas is definitely another prevalent reason why your cat still has fleas after treatment. For better results, it is important to treat all of the animals in your house.

Resistance Problems

One possibility of why your cat may still have fleas after being treated is that there is some sort of resistance problem.

Resistance to flea treatments has been seen on occasion. In many circumstances, fleas are not totally eliminated since the medicine fails to provide the expected outcomes.

Not undertaking the complete Process.

If your cat still has fleas after treatment, it is likely because you missed a step in the treatment process. Most flea treatments involve a multi-step approach, and if one of those steps is skipped, the fleas will not be eliminated.

Additionally, it is important to remember that the life cycle of a flea involves several stages, and even if you treat your cat for fleas, you may still have pupae hatching in the environment for a few months.

Not waiting long enough.

The most common reason for flea treatment failure is not understanding how long it takes to get rid of an infestation. Most treatments, whether they are over the counter or prescribed by a veterinarian, take time to work.

If you do not give the treatment enough time to work, you may end up with a continued infestation.

In fact, it is common for people to stop treating their cats after a few weeks when they don’t see any more fleas. However, did you know that the pupae can wait 12 weeks to hatch, which means you need to treat them for 12 weeks without a gap to beat them?

Therefore, to avoid this situation, be sure to use preventive flea products regularly- on your cat and in your home- to give them both protection against infestations.

Can you reapply flea treatment to your cat if it doesn’t work the first time?

If your cat still has fleas after treatment, it is important to consult with a veterinarian to find out why the first treatment didn’t work.

As for reapplication, well, In some cases, doubling up on dosing can be dangerous for your cat and unnecessary if you are using already using an effective flea product.

In fact, there are a number of different types of flea treatments available, so it is important to consult with your veterinarian to find the right treatment for your cat if the initial procedure did not work out well.

What to do if the flea treatment still isn’t working on the cat

Woman Applying Tick And Flea Treatment To Pet Cat

If the treatment for the cat’s fleas is still ineffective, it is time to take it to the veterinarian. You have no need to feel embarrassed; fleas are a common problem for veterinarians, and their presence in your house is in no way indicative of your ability to properly care for your cat.

A specialist will be able to determine what went wrong and assist you in eliminating the fleas with the right and effective treatment.


Fleas are a frequent parasite that affects cats. These bugs are so tenacious that it’s not uncommon for them to reinfest an area. Several factors, including insufficient care, resistance issues, and leaving the environment and other pets out of the equation, lend credence to this.

However, re-infestation may be cured, and in this instance, talking to your veterinarian is your best solution.

About the author

A biotechnologist by profession and a passionate pest researcher. I have been one of those people who used to run away from cockroaches and rats due to their pesky features, but then we all get that turn in life when we have to face something.