A single flea stands in a field of white pet hair.

What to Do with a Cat Flea Infection

Cat fleas are a very common and extremely annoying problem for not only cats but also their owners. Before we go any further, please make sure you understand this. It is critical to never use dog flea control products on your cat without the approval of your veterinarian.Using the wrong treatment on a cat can be fatal.

What Are Cat Fleas?

Fleas are small, wingless and brown insects that love to jump on cats as part of their life cycle. When they do, their particular mouthparts pierce the skin and siphon blood. During the flea bite, the flea injects a small amount of saliva into the skin to prevent blood coagulation.

Some cats may have fleas without showing discomfort, but an unfortunate number of cats become sensitized to this saliva causing an allergic reaction referred to as “flea allergy dermatitis.” In highly allergic cats, the bite of a single flea can cause severe itching and skin infections. Cat fleas are one of the most Common Cat Health Problems You Should Know About.

The Lifecycle of the Cat Flea

Fleas love warm weather and humidity and generally begin their optimal breeding cycle with temperatures around 70°F to 85°F and humidity near 70%. Fleas can become dormant in the winter but the heat will bring very fertile conditions ripe for infestations. Fleas can still reproduce in the winter depending on the temperature and environment. They can thrive all year in homes.

The flea’s life cycle has four stages that include egg, larva, pupae, and adult. The adult flea jumps on your cat to obtain a blood meal and breed leading to the first phase…eggs.

Eggs: The adult flea lays eggs either directly on the cat where they may drop off or the flea goes back on the ground and lays their eggs there.
Larvae: The eggs eventually hatch into larvae that live on the ground such as in carpeting, cracks in hardwood floors, corners, on patios or in the grass. The larvae survive by ingesting dried blood, animal dander, and other organic matter.
Pupae: To complete the flea life cycle, larvae develop into pupae. In cold weather, the pupae can lie dormant for months then quickly transition to adults during the appropriate heat and humidity conditions.
Adult: From the pupae comes the adults which then jumps back on the cat to get a blood meal and breed. An adult flea can lay 15 to 20 eggs per day and over 500 in her lifetime. Her eggs can be adults in as little as two to three weeks. The flea spends the majority of its life cycle of the pet. In fact, for every flea you see ON your cat, there are about 200 life forms in the flooring, yard or carpet of your home. This is why you don’t always see fleas on your cat.

You can quickly see how one or two fleas can quickly become an infestation. During the peak months, however, one flea can become as many as 100,000 in just 30 days!

Symptoms of Cat Fleas

Symptoms of cat fleas include:

Scratching or biting of the skin
Hair loss over the legs or back
Raw open wounds or small scabs over the neck and back from scratching and secondary bacterial infections
Identification of fleas. You can see fleas sometimes when you part the hair and look at the skin. The most common areas fleas love to be on cats are over the lower back just at the base of the tail, abdominal area, and around the neck.
Evidence of “flea dirt”. Another way to determine if fleas are present is to look for flea dirt. This is actually the bowel movement of the flea that consists of digested blood. It looks like fresh ground pepper over the back or neck of your cat. You can use a flea comb to help find fleas and flea dirt
Excessive shedding

Diagnosis of Cat Fleas

The diagnosis of cat fleas involves the identification of fleas, evidence of “flea dirt”, or lesions consistent with fleas. Because the flea spends the majority of its life in the environment it can be difficult to see a flea on your cat. It is also common for the meticulous cat to sense a flea on himself or herself and bite, chew and eat the flea thus destroying the evidence.

You can check your cat carefully for fleas or for signs of flea dirt. Be sure to focus on the area over the back just in front of the tail. A flea comb can be helpful.

A flea comb has narrow tines that are closer together than the typical adult flea. Running a flea comb across your cat can yield fleas that can otherwise be evasive.

You can also evaluate the flea dirt to determine it is indeed flea dirt and not just dirt. Because the flea feces contains digested blood, you can often detect subtle red coloration when placing the flea dirt on a moistened white tissue or paper towel.

What To Do If You Have Cat Fleas

Fleas can be annoying but also spread disease, cause skin infections, and tapeworm infections. If you see any of these signs or have concerns about fleas, please contact your veterinarian.

There are many types of flea control products on the market. There are flea collars, shampoos, sprays, powders, and dips as well as newer and more effective products such as oral and systemic spot-on insecticides.

Battling cat flea infestations requires killing the fleas that are on the cat or kitten while also attacking areas where the eggs, larvae, pupae, and adults all congregate in the yard or carpet. Because some stages of a flea’s life can persist for months, chemicals with residual action are needed and should be repeated as recommended based on the product.

If you have a flea infestation, you need to treat your environment as well as the cats.

Dealing with Fleas on Kittens

It is important to note that many flea control products are not approved or safe for cats under the age of 8 weeks. You can use flea combs and baths for very small kittens as well as an oral adulticide called nitenpyram (Capstar®) that when given begins to kill fleas in 30 minutes. It is critical to NOT use a dog flea product on your kitten without the approval of your veterinarian.

Most flea products are approved for cats over the age of 8 weeks.

Dealing with Fleas and Adult Cats

For adult cats, there are several products on the market that can deal with fleas.

Insect growth regulator (IGRs) products work to control fleas by interrupting the development of fleas by killing flea larvae and eggs. These products do not kill adult fleas but can dramatically decrease the flea population by arresting their development. Products include lufenuron (Program) that can be combined with heartworm protection lufenuron/milbemycin (Sentinel®). Methoprene and pyriproxyfen (Nylar®) are also very effective IGRs that are available as sprays or collars.
Products that kill adult fleas (adulticides) work well and rapidly. These include both spot-on and oral products. Spot-on products are usually applied to your cat’s skin between the shoulders. The medication is absorbed into the skin and distributed throughout the body. Spot-on products include Selamectin (Revolution®), fipronil (Frontline®), Metaflumizone (ProMeris® and ProMeris Duo™), and imidacloprid (Advantage®).

Many of the prescription flea products are safe, easy to use, effective and some have additional benefits such as efficacy against gastrointestinal parasites, ear mites, ticks, and mosquitoes.

As with kittens, it is critical to NOT use a dog flea product on your cat without the approval of your veterinarian.

Tips for Dealing With Cat Fleas

It is also important to treat all pets in the home at the same time. Dogs and cats can share fleas.
Repeat environmental treatments as recommended that might be every 2 weeks for a few months. Follow label directions.
If your cat goes outside, don’t forget to treat the porch, doorway, sidewalk, driveway, yard, and any other place your cat frequents.
If you have both dogs and cats your dog or cat goes in the car with you, don’t forget to vacuum and spray the car.
Vacuum, treat, and carefully wash all pet carriers used.
Treat climbing posts and cats trees.
Wash all bedding weekly in hot water.
The vacuum cleaner can help remove flea eggs and immature forms. Remove the bag or empty the canister outdoors at the end and take the waste to the outdoor trash.
Consider the help of a licensed pest control company. These professionals have access to a variety of insecticides and they know what combinations work best and provide a guarantee.
Use ONLY topical flea products recommended for your cat’s age and weight.
Monthly topical or oral prevention can be effective in controlling and preventing flea infestations.

With all these choices, it is best to consult with your veterinarian regarding the very best products for your cat and your individual situation. Dealing with an infestation is different than planning flea prevention. The most effective and safest cat flea prevention centers on routine use of quality prescription prevention products for all pets in the home. Talk to your vet to decide what is best for you, and your cats.