Cat Fleas

"Cat fleas cause an allergic reaction that in turn causes itching, hair loss and dry skin called flea bite dermatitis. Treatment involves collars, a spot on application or medications."

Allergies from cat fleas are caused when a flea bites your cat's skin. The reaction itself is due to sensitivity to the saliva in the flea's mouth. A typical flea allergic reaction will have your cat itching the moment they come in contact with the fleas. Itch from flea allergies could even continue after all the fleas have been killed.

Recent studies have shown that flea saliva contains around 15 different allergens that can cause reactions in sensitive cats.

An adult flea is a small dark brown insect that can be seen with the naked eye. Flea eggs look like specks of salt and pepper.

Symptoms of Cat Flea Allergies

Common symptoms of cat fleas include itching, red pimples or bumps on your cat's behind (rump), under the legs, base of the tail, groin or belly. The skin may appear red and inflamed. When your cat goes to itch this area, their hair can fall out and their skin becomes dry. If you draw an imaginary line around the center of your cat, and only see symptoms in the rear half, it is probably fleas.

A flea allergy tends to be seasonal and will cause worse symptoms during summer and fall when fleas are most active and when the warm humid environment exists that they like.

Fleas will live on your cat for up to 115 days and only 1 to 2 days if not on a host. A female flea can give off 2000 eggs which can incubate in carpet and under furniture in the house. The eggs will then hatch in days or months depending on the conditions in the house (ideal temperature is 65 degrees). The fleas then seek a host such as a pet. If they don't find one they will die in 1 to 2 weeks.

If the condition continues, the skin can become crusty and infected causing crusty lesions.

Diagnosing Cat Flea Allergy

The best way to check for fleas is to place your cat on a piece of white paper. Brush the coat and if you see white and black grains of what looks like sand. The droplets are actually lea eggs and feces. There is also a skin test that your veterinarian can use to test for flea allergy and fleas.Treatment of Flea Allergy

Most cats are cured when the fleas are eliminated from their body, hair and where they live. All pets that live with the cat should be checked as well. Your vet will treat fleas with oral medication or with a spot-on treatment. You can also use an antihistamine to help with the itching, or your vet may prescribe corticosteroids for that purpose. Antibiotics may be prescribed if secondary infections have set in due to excessive scratching. You can either try natural approaches to flea removal or prescription medications from your veterinarian.

Eliminating fleas on your cat just removes only part of the flea problem. Flea eggs fall from your cat and adult fleas can easily jump from your cat into your environment. If you only treat your cat, she will quickly be re-infested with fleas that are still living in your home. You must kill the fleas on your cat AND in your home.

Treatment Program for Cat Fleas

There are several products that can help to prevent cat fleas. Do not use products made for dogs on cats since they could cause harm.

We recommend starting treatment with a shampoo or dip and shampoo combination. One dip to consider is Dermisil Flea Dip since it mixes with your cats regular shampoo or you can buy the shampoo offered by the same company. Continue with the shampoo until fleas are gone.

Comb your cat every other day with a Flea Comb Kill the fleas on the comb by dipping the comb in alcohol or detergent.

See our complete list of cat care flea skin and outdoor products.

Feline Flea Treatment Options

Today, liquid products that apply directly to the skin or oral products should be enough to protect against feline fleas. Products such as Frontline Plus, Revolution and Advantage and Program should work well. Consult your veterinarian to determine if you need to go beyond these products to other methods of treatment and prevention.

Collars - Popular and widely used, yet aren't always effective. Collars are only a partial solution and should be supplemented with other approaches.

Shampoos - Effective option for mild cases and when the areas where the cat lives no longer has fleas. Shampoos with Pyrethin are best for younger cats.

Powders and dusts - Best used with other products such as shampoos. They are used 2 times per week and must be worked into your cat's coat.

Sprays and foams - Look for water based sprays (vs. alcohol based sprays which can irritate skin). Use sprays in between shampoo treatments to kill any fleas that may have jumped on your cat from the environment that you missed. Spray treatments last for up to 14 days.

Topical hydrocortisone creams - sre are used for dermatitis, but may cause side-effects when used regularly. Consider a herbal cream instead.

Herbal Creams - creams such as FleaDerm will effectively treat, soothe and prevent flea bite dermatitis without the side effects of prescription creams for this condition.

Insecticide dips - The best choice for thoroughly killing fleas on your cat. Most dips need to be applied every 7 to 10 days. Follow manufacturers directions and avoid using on kittens without the advice of a veterinarian.

Liquid Medication - Program (lufenuron suspension) given once a month, mixed with food. Cats must be at least 6 weeks old.

You must rid your house of fleas or else your cat can suffer a re-infestation. This may include use of a professional exterminator, carpet shampoos sprays and foggers. Different products are used for indoor and outdoor infestations. Benzarid is a good option for indoor cleaning. The same company offers steamers for safe outdoor treatment.

If you are cleaning carpet fleas the best product to use is the borax based Fleabusters Rx For Fleas Plus. Borax is highly effective at killing fleas.

For more on cat flea care treatment options follow this link.


Greek, Jean, DVM, ACIDM
New Hope Animal Hospital
Atopic Disease and Allergy

Beale, Karin M. DVM
Gulf Coast Veterinary Specialists
Atopic Dermatitis: Clinical Signs and Diagnosis

Ihrke, VMD
Professor of Dermatology
School of Veterinary Meicinea
University of California
Flea Allergy Dermatitis

Cat Owners Home Veterinary Handbook
Delbert G. Carlson DVM and James M. Giffin, MD


Ask Our Vet a Cat Flea Care Question

Have a feline flea related question for our Vet? She'll answer it for free. Please describe any flea care products that you are using as well as your cat's medical history. Include age, sex, breed, medications, skin conditions, changes in behavior such as eating problems or urination, and anything you believe may be of help.

We will do our best to answer questions quickly (it depends on how many we receive each day). If you need an immediate response we suggest using this online cat veterinary answer service that is available 24 hours a day.

[ ? ]

Upload 1-4 Pictures or Graphics (optional)[ ? ]


Click here to upload more images (optional)

Author Information (optional)

To receive credit as the author, enter your information below.

(first or full name)

(e.g., City, State, Country)

Submit Your Contribution

  •  submission guidelines.

(You can preview and edit on the next page)

Other Flea Related Reader Questions and Vet Answers

Click below to see contributions from other visitors to this page...

How to Stop Excessive and Seasonal Cat fur Licking 
Hi, I have a two year old short haired female tabby outdoor cat although she never usually ventures far. About a year ago she went missing for about 3 …

my wife and i noticed excessive hair floating around upstairs on the wood floors. we have minimal carpet. we use wood products twice a week and are vacuum …

Cat Flea Allergy Dermatitis Treatment 
I have a havanah brown and siamese mixed black cat who is severly allergic to fleas. We treat all three of our cats during the flea seasons but somehow …

Fleas on Kittens Not rated yet
I have a 14 wk old female kitten. On my cream bedding I've noticed lots of tiny brown dots, some about 1mm long, some slightly curled. I can brush …

Get Rid of Fleas Not rated yet
Reader Question: My cat has a flea infestation and I believe she is now anemic from them. I have tried Hartz Ultra Guard for fleas one spot treatment …

Emma (cat is JT) Not rated yet
We've tried EVERYTHING. Nothing works. We've cleaned the carpets and all the cloth items in the house, used carpet powder and sprays and flea collars …

Click here to write your own.

From Cat Fleas to Cat Health Guide Home