Flea Saliva Allergy in Cats

Flea Saliva Allergy in Cats - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost

What is Flea Saliva Allergy?

Allergies are very common in cats, and they can be allergic to many different things, including fleas. Many people believe that flea bites are the cause of the intense irritation of cats’ skin; however, it is the actual saliva of the fleas that cause the reaction so many cats suffer from. 

When fleas bite into a cat to consume blood, they inject their saliva into the skin. When a cat is allergic to the saliva of fleas, their immune system will react much more sensitively to one single flea bite and the accompanying saliva, which contains specific proteins and antigens.

If a cat is allergic to the saliva of fleas, the intensity of the flea bites will be worse. Cats that do not have an actual flea saliva allergy will itch only mildly to moderately, even with over a dozen flea bites. A single flea bite on the skin of an allergic cat will cause more pain and discomfort from the saliva. With a flea bite allergy, cats can also develop secondary infections, such as staph infections which can become very severe and even life-threatening. Yeast infections can also develop, which will require a secondary method of treatment.

Flea saliva allergy in cats is due to cats having an allergic reaction to the saliva of fleas after being bitten. The saliva from flea bites can cause intense itching and irritation of the skin.

Symptoms of Flea Saliva Allergy in Cats

A cat that has a flea allergy will show sometimes serious symptoms that will need a veterinarian’s attention. Symptoms include:

  • Extreme itchiness
  • Claws and scratches face and body
  • Scabs and crusty skin
  • Open sores on skin
  • Loss of hair
  • Agitation
  • Flea dirt or blood particles in fur


There are other types of pest and parasite infections that can affect cats of any breed. Types of allergies to other pests include:

  • Ringworm
  • Ticks
  • Bee stings
  • Insect bites
  • Spider bites
  • Fungal infections

Causes of Flea Saliva Allergy in Cats

Causes of flea saliva allergy are specifically related to being bit by even one single flea. More causes of flea saliva allergy include:

  • Flea saliva is an allergen or antigen to specific cats
  • The allergic cat has an over reactive immune system in response to the saliva
  • A reaction occurs, either locally or generalized

Diagnosis of Flea Saliva Allergy in Cats

If you notice that your cat is scratching at his skin more than normal, make an appointment with your veterinarian. More than likely, you will already know that your cat is having an allergic reaction to fleas, as you will see the “flea dirt” on the hair and coat of the cat. You will also see residue that may appear bloody. To be sure, one thing you can do is take a small cup of water and gently pour it over your cat’s fur. If you see the water turn red, or “bloody” after making contact with the flea residue, then you will have a good idea your cat has fleas and a possible flea allergy.

Your veterinarian will take a closer look at your cat’s skin. He may go ahead and take lab work, such as blood work, a urinalysis, and a biochemistry profile. This will rule out any other health conditions.

Diagnosis will be made by the veterinarian carefully observing your cat’s skin, coat, symptoms, and possible intradermal testing. Your veterinarian may feel he doesn’t need to perform a specific test for diagnosis because even though a skin test is performed, false positives or false negatives can occur.

Treatment of Flea Saliva Allergy in Cats

If your cat is allergic to flea saliva, fortunately there are options to treat it. Treatment methods recommended by your veterinarian may include:


Your veterinarian may bathe your cat in a mild detergent that is hypoallergenic, or he may bathe him in a medicated detergent. 

Flea Treatment

There are topical ointments and medications that cats can be given to kill flea eggs, live fleas, and larvae within a few hours. This may be done in conjunction with the bathing.


Your veterinarian may go ahead and treat the bites on the skin by applying a topical ointment or giving your cat an antihistamine to counteract the allergic reaction he is having. Corticosteroids can also help your cat; the veterinarian may present this as an option.

Environmental Treatment

Although the application of treatment is effective, it is still important to clean the environment to kill the fleas and larvae within the home. This is to protect any other animals and to prevent you from becoming a victim. Keeping your cat’s area free from fleas will greatly improve their health and well-being, even if they are treated. Fleas multiply at a rapid rate, so cleaning will kill them and eradicate their reproduction and life-cycle. Vacuuming and disposing the vacuum cleaner bag is very necessary to get rid of the fleas. There is also flea powder and spray on the market.

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Recovery of Flea Saliva Allergy in Cats

Once your cat is treated for a flea saliva allergy, he should recover once the medication takes effect. The key to making sure your cat continues to recover is prevention. Fleas are easy to prevent if the proper steps are taken. Once you have thoroughly vacuumed and cleaned your home, include laundering any bedding and pillows. In order to prevent fleas from recurring on your cat or other animals, be sure to continue the treatment your veterinarian recommended. Flea treatment needs to be consistent and applied every month in order to keep your cat’s skin a barrier for these pests.

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