Fleas & Flea Allergy Dermatitis

Also called: FAD, flea-bite hypersensitivity, miliary dermatitis

• Cats
• Skin & parasites
• Any

Fleas are extremely common external parasites. Beyond irritation, some cats become allergic to proteins in flea saliva, and even a single bite can trigger intense itching and skin disease — flea allergy dermatitis, one of the most common skin conditions in cats. Most fleas in a home are in the environment, not on the cat, so treating the home matters too.

Signs to look for

• Excessive scratching, licking, or over-grooming
• Hair loss, especially over the lower back, base of the tail, neck, and head
• Small scabs/crusts across the body ('miliary dermatitis')
• Red, irritated skin and secondary sores
• 'Flea dirt' (black specks that turn rusty-red when wet) in the coat

How a vet diagnoses it

Usually a clinical diagnosis from the pattern of skin signs plus finding fleas or flea dirt (e.g. flea-comb test). Because cats groom away evidence, FAD may be diagnosed even without visible fleas.

Treatment

Effective, vet-recommended flea control for the affected cat and all household pets, year-round, plus treating the home environment (vacuuming, washing bedding). Short-term corticosteroids may relieve acute itching. Never use dog flea products on cats — some are highly toxic to cats.

Monitoring at home

Itch/skin condition, recurrence, and consistency of preventive flea control.

Who tends to get it

Any age, breed, or sex; cats with other allergies are more prone. In Australia, fleas are a year-round problem.

Sources

• International Cat Care — Fleas and flea control
• VCA Animal Hospitals — Flea Allergy Dermatitis