3 Cat Allergy Causes

Find out how cat allergies to fleas, food and inhaled allergens can cause a cat's itching from veterinary expert Arnold Plotnick, DVM.

Sneezy cat? See why. Via Pixabay


My indoor cat, a small Manx, is getting these small hard, almost hard scab like spots on her head and neck area. They aren’t fleas, but she is frequently scratching them and I don’t know what they might be or if there is something we can get or do for her. Do you have any ideas?


Your cat’s small scabs in the head and neck area indicates skin inflammation called “miliary dermatitis.” They are likely a result of some type of allergic dermatitis. Flea allergy, food allergy, and atopy (allergies to inhaled allergens) are the three most common cat allergies.

1. Flea Allergy

A totally indoor cat like yours is unlikely to be affected by fleas (although it is possible for people to track fleas into the house on clothing or shoes). Examine your cat’s hair coat for evidence of fleas, i.e. live fleas or flea droppings (little black specks that look like grains of pepper).

2. Food Allergy

Cat food allergy can cause miliary dermatitis, especially around the head and face. To prove whether your cat has become allergic to the protein (or, less likely, the carbohydrate) source in the food, a feeding trial in which your cat is fed a hypoallergenic diet — a diet containing a protein source to which your cat has never been exposed — can be attempted. Most vets carry prescription diets like this, in which the main protein source is rabbit, venison or duck, and the carbohydrate source is green pea. The cat must be fed this diet only; no treats or snacks of any kind can be fed during the trial, or the results will be inconclusive. If there is no improvement after 8 to 10 weeks, then food allergy is unlikely.

3. Allergy To Inhaled Allergens (Atopy)

Allergy to inhaled substances (atopy) is the most likely cause for your cat’s scabby skin. Cat atopy could be a seasonal allergy, for example, an allergy to some kind of plant that is in bloom at this time of year in your geographical region. Or your cat could be allergic to something your cat is continuously exposed to, such as house dust mites.

Testing Cats for Allergies

Intradermal skin testing, performed by a veterinary dermatologist, can help determine the specific allergen, but this is rarely necessary. To control your cat’s itching, try anti-histamines in combination with omega-3 fatty acids. If this does not control the itching and scabbing on your cat, try a short course of an anti-inflammatory drug such as prednisolone. Cats initially take a higher dose, which is then quickly tapered as the itching comes under control.

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Cats · Health and Care