What are the signs of flea allergic dermatitis?

The most consistent signs of dermatitis are scratching and reddening of the skin. Apart from this the signs will depend somewhat on the severity and cause.

There may be scabs, sores, crusting, pustules, flaking, oily discharge, discharge, thickening, colour changes (usually darker or redder), hair loss over the back and in extreme cases bleeding. The presence of live fleas or flea dirt (black specks that turn red if wet) usually indicates a flea allergic dermatitis.

If puppies or kittens are exposed to fleas very early on in life, they are more likely to become sufferers of flea allergic dermatitis later on in their lives.

For this reason, it is vital to treat kittens, puppies and their mothers as early on as possible. Individual flea allergic pets have different thresholds above which they show clinical signs.

Beautiful dog Brandy at Salisbury Clinic reception desk

Our lovely visitor at the reception desk Brandy was just asking the same question – what is flea allergic dermatitis?

The threshold could be hundreds of biting fleas causing intense biting and scratching in your pet or just one flea which you may never see. Pets are allergic to the saliva of the flea.

A flea allergy could kill your pet. It could lead to so much biting and scratching if they are badly allergic which causes a secondary skin infection with what we call a deep pyoderma where the normal skin bacteria multiplies and causes a deep infection. This can lead to the bacteria entering the bloodstream and poisoning it.


The obvious first line of treatment is a veterinary product to kill the live fleas. A flea product such as a spray for the home should also be used as well as a product to sterilise the life cycle of the flea if your dog suffers from flea allergic dermatitis.

We then treat the secondary infection with antibiotics and the itching with a course of anti-inflammatories. Medicated shampoos may also help to soothe your pet’s irritated skin.

Speak to us about any further concerns you may have – we have excellent flea products available for our clients!

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