Allergic Dermatitis in Cats

SACDERMVET

7465 Rush River Drive Suite 830

Sacramento CA 95831

916 234 5722

Allergic dermatitis in cats is due to the immune system overreacting to something that is normally harmless. 

Cats often show this reaction by overgrooming and will have patches of hair missing and raw areas of skin but they may do this in secret. 

Cats can be allergic to: 

1) Fleas, even before you see them.

2) Pollens, dusts and moulds. Signs may vary with season.

3) Less commonly food. 

Cats can be allergic to any combination of these and they tend to amplify each other and infection and itching can further complicate the appearance. 


Treating infections is important but these are almost always a complication not the original problem and cats seem less prone to them than dogs. Cats who are infected with FIV seem to have more problems with skin infections. 


Corticosteroids (steroids) such as prednisolone are commonly used for immediate itch relief and to control inflammation. They are inexpensive and act quickly but have a wide range of  side effects and some are not immediately obvious.  They effectiveness and side effects vary with the individual patient. Cats do not seem to respond to prednisone which is used on dogs and humans. We use tablets or liquids as injections tend to carry a higher risk of side effects, such as diabetes in cats. 


The inflammation in the skin of allergic cats will often continue even if the original cause has gone, so we tend to treat cats until their signs are well controlled before we start to decrease medications as well as trying to manage the underlying cause


Cyclosporine is a drug that we have used for about 10 years to control allergic dermatitis and otitis in cats. It takes a few weeks to start to work and we use it in cats that are not well controlled with prednisolone or need higher doses.


We can do allergen immunotherapy injections in cats for environmental allergies but they are not helpful for food or flea allergy.


Milder medications such as specific types of fish oil and antihistamines may also be helpful. We may use them as prevention and maintenance but many cats will not take a lot of oral medications

Eosinophilic Dermatitis

Cats often respond to allergic skin disease with a type of white blood cell called an eosinophil. Neutrophils are commonly seen with skin damage or infection but eosinophils contain orange staining granules that can produce severe itching and inflammation. Eosinophils also tend to recruit other eosinophils and this can keep itch and inflammation going even if the original cause has resolved.