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Flea allergy dermatitis (FAD)

Also known as: Flea bite hypersensitivity

Quick answer

An allergic reaction to flea saliva — a single bite can trigger intense itching. Year-round flea control is essential even if fleas are not seen. See your vet if itching persists despite flea treatment, or skin becomes infected.

Definition

An allergic reaction to flea saliva — a single bite can trigger intense itching. Year-round flea control is essential even if fleas are not seen.

Symptoms

  • Intense scratching and biting at skin
  • Hair loss over the rump and thighs
  • Red, inflamed skin
  • Hot spots or scabs
  • Restlessness

When to see a vet

See your vet if itching persists despite flea treatment, or skin becomes infected. All pets in the household need concurrent flea control.

Related guides & tools

Frequently Asked Questions

What is Flea allergy dermatitis (FAD)?
An allergic reaction to flea saliva — a single bite can trigger intense itching. Year-round flea control is essential even if fleas are not seen.
What are the symptoms of flea allergy dermatitis (fad)?
Common signs include Intense scratching and biting at skin, Hair loss over the rump and thighs, Red, inflamed skin, Hot spots or scabs. This is not a complete list — individual pets vary. See linked guides for fuller context.
When should I see a vet about flea allergy dermatitis (fad)?
See your vet if itching persists despite flea treatment, or skin becomes infected. All pets in the household need concurrent flea control.