Flea allergy dermatitis in cats

Flea allergy dermatitis in cats is caused by a reaction to the saliva of fleas. Fleas are an extremely common problem for cats. The symptoms often include extreme itching, which can lead to a skin infection. Any age of cat can develop this problem. 

When fleas bite cats, their saliva goes into the bloodstream. This can cause a condition called flea allergy dermatitis. It may only take one flea bite to cause a severe reaction. This is an easy condition to treat if caught early, and it can be prevented with strict parasite control. Cats with flea allergies can live a normal and comfortable life.



What is flea allergy dermatitis in cats?

Flea allergy dermatitis is a common type of allergic reaction in cats. It can occur at any stage of your cat’s life.

  • This is a common cause of itching in cats
  • Fleas are not always seen on the coat
  • When fleas feed on cats, they pass their saliva into the bloodstream
  • Cats can develop an allergy to the saliva of fleas
  • It only takes one flea bite to cause a severe reaction
  • The symptoms can be very mild but may lead to self-trauma and skin infections if left untreated
  • If caught early, symptoms should clear within a few weeks
  • Treatment is usually straightforward, unless there is a secondary infection of the skin

If you think your cat has fleas or a flea allergy, contact a vet to discuss the best treatment plan.

picture of a cat flea
Image of a cat flea


Symptoms of flea allergic dermatitis in cats

The signs of flea allergy dermatitis tend to develop around the back, hindlegs, and top of the tail.

  • Signs of being itchy, such as biting, licking, or scratching. Cats are good at hiding this.
  • Restlessness
  • Hair loss, overgrooming and areas of alopecia
  • Fleas or flea dirt in the coat
  • Scabs, crusts, or a rash on the skin. The rash can feel like small pieces of grit under the hair
  • Thickened, darkened or red patches of skin
flea allergy dermatitis in cats
Area of body typically affected by flea allergies


flea allergy dermatitis in cats hair loss
Hair loss in a cat due to a flea allergy
cat red itchy skin flea allergy
Cat’s can also develop a rash called Miliary Dermatitis due to a flea allergy

Find out more about Fleas in cats and other reasons why your cat might be scratching Itchy cats


Are some cats more at risk of flea allergy dermatitis?

Any cat that has fleas is at risk of developing flea allergy dermatitis.

It can affect cats of any breed and age.

It may be more common in cats that have other allergies or sensitive skin.

It is also more common in cats that are not on regular parasite control.

If one of your pets has fleas, it is most likely that all the other pets in the household will also have them.


Is my family at risk of catching flea or flea allergies?

  • Cat fleas can bite humans but don’t live on our skin.
  • Flea bites on humans often appear as a red spot or scab.
  • These can become itchy and infected.
  • We recommend speaking with a pharmacist or doctor about how to treat this.



How is flea allergy dermatitis diagnosed in cats?

Flea allergy dermatitis is usually diagnosed based on the symptoms your cat is showing. This includes the area of the body that is affected.

You can do the flea paper test to check for flea dirt in your cat’s fur

cat flea test flea comb
Brush your cats hair onto a white piece of paper
flea dirt cat hair
Flea dirt will leave red streaks when water is added

Further tests include

  • Skin scrapes, smears, or hair plucks
  • Skin biopsy
  • Blood and urine tests
  • Allergy testing (on the skin or from a blood test) may help confirm different types of allergies


Vet treatment

Vet treatment for flea allergy dermatitis

There are different parts to the treatment of flea allergy dermatitis in cats.

Flea treatment

  • To get rid of and protect against further fleas on your cat’s coat
  • Usually as a tablet, injection or spot-on
  • Prescription medication usually has a quicker action. Fleas may still bite your cat before the product kills them. Getting rid of fleas from the environment is therefore a very important step.
  • Treatment of the home and any other pets must be done thoroughly, with vet-recommended products.

Itch treatment

  • Anti-itch medications are often required, including steroids and antihistamines
  • Usually as a tablet or injection

Skin treatment

  • It depends on how severe the infection is
  • Skin infections, such as spots or a rash, may need antibiotics
  • Usually as tablets, injections, shampoos or creams
  • Regular check-ups are important to check the infection has cleared


Home treatment

How to look after a cat with flea allergy dermatitis at home

Get rid of the fleas

  • Treat all the pets in the household with vet-recommended flea control.
  • 95% of fleas live in the environment. An important step is to treat your home and car.
  • Household sprays are usually the most effective. Use these as advised by your vet.
  • Wash all bedding, blankets, and clothes that your cat has been in contact with at over 60 degrees celsius.

Home remedies

  • Check with your vet before using any home remedies, as some can cause more harm than good
  • Skin supplements containing omega oils can help improve itching and protect the skin barrier
  • Antibacterial and calming sprays or mousses can be helpful for irritated skin
  • Use a buster collar or pet medical suit to prevent self-trauma


Costs of treating flea allergy dermatitis

The costs involved with flea allergies can vary depending on how quickly treatment is started.

Costs will be higher if there is a secondary skin infection.

Long-term treatment costs are low. It usually involves regular parasite control and occasional anti-itch medication if needed.

It is much easier to prevent than to treat this condition.



Tips on how to prevent flea allergy dermatitis in cats

Prevention is much easier and more cost-effective than treatment.

  • Strict flea control is necessary. Use a vet-recommended flea-preventative product all year, even if your pet is indoors. These are usually applied monthly, but some products may last longer. Treat all pets in the household. Topicals
  • Groom and brush your cat regularly to check for anything abnormal in their fur or on the skin.
  • Vacuum regularly, and put your cat’s bedding in a hot wash cycle.
  • Use a household spray that kills fleas; these often last 6-12 months. This is an important step, as the majority of fleas live in the environment.
  • Limit contact with stray or unknown animals who may not be on regular flea control.


When to worry

When to worry about flea allergy dermatitis in cats

Seek help from a vet if:

  • Your cat is extremely itchy
  • Your cat has thickened or weepy skin
  • You have a very young or elderly cat with fleas

Contact us at Joii if:

  • You have questions about the best flea control to use
  • Your cat has any mild skin problems
  • You want to check if your cat has fleas
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