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ChewyFlea & Tick / Health

Help! My Cat Has Fleas: Signs, Treatment and Prevention

Finding out your cat has fleas can cause a bit of dread and anxiety. Fleas can be easy to prevent but challenging to control once they’ve taken up residence on your kitty and in your house.

If your cat has fleas, there are tons of flea treatments to get rid of these blood-sucking pests. You just have to choose the right course of action with your veterinarian.

What Are Fleas?

It might make your skin crawl to learn exactly what fleas are, but understanding their biology can help when treating cats with fleas.

“Fleas are blood-sucking ectoparasites,” says Sandra Mitchell, DVM, owner of All Creatures Veterinary Services in Bangor, Maine. She adds that fleas can live on the outside of any furry pet in your home, including cats, and feed off of them by biting and then sucking the animal’s blood.

The Companion Animal Parasite Control Council, a not-for-profit organization that spreads awareness about the affect parasites have on animals and people, notes that while there are several species of fleas, the most common type to infest cats is Ctenocephalides felis.

Dr. Mitchell says that temperature plays a big factor in flea populations, noting that these pests tend to mature faster at warmer temperatures than cooler ones.

Fleas experience a four-stage life cycle:

  1. Egg: Adult female fleas lay eggs after feeding off a host’s blood.
  2. Larva: After anywhere from two days to two weeks, worm-like larvae hatch from the eggs. The larvae feed off of “flea dirt,” which is the blood-filled feces adult fleas leave behind, for up to roughly three weeks.
  3. Pupa: Then, the larva spins into a cocoon for the next stage—the pupa stage, which can last for a week or months. “Fleas can move through the pupae phase very quickly or stay protected this way for many months until the conditions are right to become an adult,” Dr. Mitchell says.
  4. Adult: Finally, the adult flea hatches from the pupa stage, and the cycle begins again.

How to Spot Fleas on Cats

Telltale signs that your cat has fleas are “scratching and itching, redness to the skin, or small red bumps or a rash,” says Melanie Thomas, DVM, a primary care veterinarian at Coral Springs Animal Hospital in Coral Springs, Florida.

Another thing to look out for is flea dirt, which can look like tiny, black specks in a cat’s fur.

“Adult fleas feed immediately on their host and create the ‘flea dirt’ found in the hair coat,” Dr. Mitchell says.

In her practice, Dr. Mitchell finds that cats are such good groomers that they eat most of the fleas, so they often can be hard to spot. But there’s one more way to confirm fleas on a cat.

“One of the most common signs is that we see white, wriggling tapeworms on the cat or in the litter box,” Dr. Mitchell says. “Tapeworms [can be] spread by fleas.”

Flea Treatments for Cats

There are hundreds of flea medications for cats, including topical, oral and collar treatments.

Dr. Mitchell’s preferred treatment for cats is selamectin, also known as Revolution.

“Revolution it is a topical medication [that’s] applied once per month to the cat,” she says. “I prefer topical medications on cats to try to prevent fleas from biting cats. [Whereas,] oral medications actually require that the flea bites the cat [first].”

When choosing a flea medication for your cat, it’s critical to get one that is made specifically for cats.

“Never use flea products on cats that are designed for dogs because some canine products are toxic to cats,” Dr. Thomas warns.

Cat parents also should be cautious when using flea products containing pyrethrin and permethrin, as cats can be very sensitive to overdoses of these substances because they’re unable to metabolize these agents quickly and efficiently, says Jennifer Coates, DVM, a veterinary consultant in Fort Collins, Colorado.

“Pyrethrins are natural compounds made by certain types of flowers, such as chrysanthemums, that can kill and repel fleas, ticks and other parasites,” Dr. Coates says. “Products containing pyrethrins that are labeled for cats are safe as long as they are used appropriately.”

Flea and Tick Medicine for Cats

Topical Flea Medicine for Cats

Etofenprox, Pyriproxyfen

Found in: Sentry PurrScriptions Plus Squeeze-On Flea & Tick Control

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 12 weeks or older

How it works: Etofenprox kills fleas by overstimulating the nervous system. Pyriproxyfen is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction.

Etofenprox, (S)-Methoprene

Found in: Adams Plus Flea & Tick Spot On

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 12 weeks or older

How it works: Etofenprox kills fleas by overstimulating the nervous system. (S)-Methoprene is an insect growth regulator that prevents flea reproduction.

 

Fluralaner

Found in: Bravecto Topical Solution

Targets: Fleas and ticks

Treatment frequency: 12 weeks

Age limit: 6 months or older

How it works: Kills fleas by overstimulating their immune systems. Sold by prescription only.

Fipronil

Found in: ShieldTec Flea & Tick Treatment

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Fipronil is a neurotoxin, which kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system.

Fipronil, Pyriproxyfen

Found in: Virbac EFFIPRO Plus

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Fipronil is a neurotoxin, which kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system. Pyriproxyfen prevents insect reproduction.

Fipronil, (S)-Methoprene

Found in: Frontline Plus, Hartz Pet Defender Plus, Onguard, PetArmor Plus, Sentry FiproGuard Plus, and ZoGuard Plus

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Fipronil is a neurotoxin, which kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system. (S)-Methoprene prevents insect reproduction.

Fipronil, (S)-Methoprene, Priproxyfen

Found in: Frontline Gold

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Fipronil is a neurotoxin, which kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system. (S)-Methoprene and Priproxyfen prevent insect reproduction.

 

Imidacloprid, Moxidectin

Found in: Advantage Multi

Targets: Fleas, ticks and heartworm

Treatment frequency: 30 days

Age limit: 9 weeks or older

How it works: Kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system. Sold by prescription only.

Indoxacarb

Found in: Activyl Flea Treatment

Targets: Fleas

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Indoxacarb uses the flea’s own enzymes to stop fleas from feeding and inhibits flea development in the environment.

Sarolaner, Selamectin

Found in: Revolution Plus

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Kills adult fleas by disrupting their nervous systems; stops reproduction by preventing eggs from hatching. Sold by prescription only.

Spinetoram

Found in: Cheristin Flea Treatment

Targets: Fleas

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Spinetoram interferes with the brain and spinal cord of susceptible insects, resulting in death.

 

Chewable Flea Medicine for Cats

Nitenpyram

Found in: Capstar Flea Tablets

Target: Fleas

Treatment frequency: As prescribed by veterinarian

Age limit: 4 weeks or older

How it works: Kills fleas by overstimulating their immune systems.

Spinosad

Found in: Comfortis Chewable Tablets

Targets: Fleas

Treatment frequency: 30 days

Age limit: 14 weeks or older

How it works: Attacks the adult flea’s nervous system, causing rapid death. Sold by prescription only.

 

Cat Flea Collars

Flumethrin, Imidacloprid

Found in: Seresto Flea & Tick Prevention

Targets: Fleas and ticks

Treatment frequency: 8 months

Age limit: 10 weeks or older

How it works: Kills fleas by disrupting nervous system function.

Tetrachlorvinphos, (S)-Methoprene

Found in: Hartz UltraGuard Plus

Targets: Fleas and ticks

Treatment frequency: 7 months

Age limit: 12 weeks or older

How it works: Tetrachlorvinphos kills fleas by overstimulating the nervous system. (S)-Methoprene prevents insect reproduction.

How Do You Know if a Flea Treatment Is Working?

Once a cat has been treated for fleas, “it generally takes three to four months to control flea populations in a household,” Dr. Mitchell says.

Patience is important because often the fleas will appear “worse” a month or two into treatment.

“This is as eggs in the environment hatch out to adults, but then after three to four months the number of fleas will diminish dramatically,” Dr. Mitchell says.

Fleas should be dead or dying, slow moving and easier to catch and kill once a cat has been treated, Dr. Thomas says.

“Owners often also note that their cat’s itching has resolved,” she adds.

Cat owners can purchase a flea comb and check their cats daily.

“They should note significant decrease in adults seen, especially if they’ve used a quality product on their cat and had the environment professionally treated for fleas,” Dr. Thomas says.

Flea Treatments for the Home

If you see a few fleas in your household, then there usually are hundreds more that you aren’t seeing, Dr. Mitchell says. You’ll need to take steps to treat a cat’s surroundings for fleas.

“I recommend regular vacuuming, at least one to two times per week,” Dr. Mitchell says. “And throw all bedding that your cats use into the washer and dryer.”

Don’t forget to vacuum couches and chairs, too, Dr. Thomas adds.

“Remember that anywhere the pet goes, the fleas have been, too!” she says.

Dr. Thomas, who lives in Florida, says that when temperatures and humidity are up, the rate at which fleas develop is high.

“They develop in shaded areas outside or in the home environment in areas like carpets, baseboards and under furniture,” she says. “I always encourage professional home and yard treatment with pet-friendly products.

Alternatively, there are many home sprays pet parents can purchase over the counter, Dr. Thomas says. These include Vet's Best Dog Flea + Tick Home Spray and Advantage Yard & Premise Spray.

In addition to the home and yard, Dr. Mitchell recommends treating the other household pets.

“All animals in the household, including all cats, dogs, ferrets, guinea pigs, rabbits, etc., should be treated for fleas, not just the cat showing signs,” she says.

Preventing Fleas on Cats

All three feline experts stress that cat parents use a good-quality flea preventive year round on all pets in the household, even for cats who do not have fleas. Many of the flea treatments listed above that kill fleas also can be used to prevent fleas.

“Talk to your veterinarian regarding the safest, most effective option for you cat,” Dr. Thomas says. “Alternatively, routine pest control care in the environment may be enough to deter your local flea population.”

By: Somyr Perry

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