Flea allergy dermatitis in cats
Also known as FAD, Flea allergy.
The most common skin allergy in cats. A single bite is enough to trigger days of intense itching, and often no fleas are seen at all because the cat removes them while grooming.
- System
- Skin and coat
- Is it urgent?
- Not usually
- Spreads to other cats
- No
- Spreads to people
- No
- Typical cost in Spain
- Consultation, €40–70; parasite treatment, €8–20 a month per animal.
The allergy is not contagious, but fleas do pass from one animal to another and can bite people.
Symptoms
- Intense itching on the back, base of the tail and neck
- Small scabs like grains of sand (miliary dermatitis)
- Bald patches from overgrooming
- Wounds from scratching
Causes
An allergic reaction to flea saliva. Indoor cats get it too: fleas come in with people, dogs or on clothing.
How it is diagnosed
Based on where the lesions are, the presence of fleas or flea dirt (black specks that turn red on damp paper) and the response to treatment.
Treatment
An effective parasite treatment for every animal in the home, treatment of the environment and medication for the itching prescribed by the vet.
No doses, on purpose: any medicine must be prescribed by your vet for your cat.
Prognosis
Very good if flea control is kept up all year round.
Prevention
A cat-specific parasite treatment all year round, for every animal in the home. Never dog products.
Frequently asked questions
Is flea allergy dermatitis contagious?
No. The allergy is not contagious, but fleas do pass from one animal to another and can bite people.
Can flea allergy dermatitis be cured?
Very good if flea control is kept up all year round. An effective parasite treatment for every animal in the home, treatment of the environment and medication for the itching prescribed by the vet.
How much does it cost to treat flea allergy dermatitis?
As a guide for Spain in 2026: Consultation, €40–70; parasite treatment, €8–20 a month per animal. Prices vary a lot between clinics and cities, and out-of-hours emergencies cost more.
How can flea allergy dermatitis be prevented?
A cat-specific parasite treatment all year round, for every animal in the home. Never dog products.
More in skin and coat
Educational content from Michipedia. It does not replace diagnosis or treatment by a vet: if you have any doubt about your cat's health, ask. Costs are a guide for Spain in 2026.