Cats and Allergic Dermatitis. Everything you need to know!

In this article:

  • What is Dermatitis?
  • Help! My cat is itchy! How To Stop Itchy cats Scratching?
  • Symptoms & signs.
  • What can cause cat dermatitis?
  • What can we do to treat dermatitis?
  • Keep in mind!
  • Medical treatment.
  • Medical facts!

What is Dermatitis?

  • Dermatitis is an inflammation of the skin.
  • The word “dermatitis” is used to describe a number of different skin rashes that are caused by infections, allergies, irritating substances and harmless substances.

  • The rashes vary from mild to severe conditions. No two cats respond the same way. We need to try many different strategies to see which ones will help your cat so be patient with us.

  • Depending on the cause of the allergy, some cats are itchy all year round and some only itch at certain times of the year. 

  • Just as people, cats can show symptoms of allergy when their immune system  recognizes certain substances as foreign ones, even if they had contact with that substance everyday. Skin is the biggest organ of  a body and also the most common one to show symptoms of allergy. 

  • The result is mobilization of inflammatory cells in the body, leading to redness, swelling, and itchiness of the skin.

Help! My cat is itchy! How To Stop Itchy cats Scratching?

  • Is your cat itching or obsessively grooming? Do you see scabs on your cat?

  • Remember that you have to use quality external parasite control products from your local vet. Even if you don`t see fleas, this doesn`t mean that your cat is free from fleas.

  • You need to identify the cause and see your vet ASAP before any secondary infections appear. Having a pruritic cat can be frustrating, stressful, and concerning; 

  • Being excellent groomers, cats that suffer from dermatitis are prone to neurotically grooming the infected area, or may even chew or scratch it.

It`s time for cat parents to seek veterinary care!  


Symptoms & signs

More severe cases of allergic dermatitis are easily recognized, while other may have very subtle signs and symptoms. Look for the following symptoms on your cat:

  • Neurotically grooming the infected area;
  • Constantly shaking the head;
  • Hair loss;
  • Brownish saliva;
  • Red, scaly or raised patches of skin;
  • Thick skin;
  • Pruritus. Licking and grooming herself more than usual;
  • Excessive biting or scratching of the skin, feet or ears;
  • Fur lost along its back and the base of its tail (flea allergies);
  • Bumps or pus-filled areas on the skin;
  • Foul-smelling odor;
  • Increased pigmentation on the skin;
  • Vomiting and diarrhea (cats with food allergies).

Recurrent otitis externa, miliary dermatitis, head and neck scratching, and eosinophilic granuloma complex lesions are other presenting patterns associated with feline atopy. The most frequent clinical signs of allergy in cats are facial pruritus, self-inflicted alopecia, miliary dermatitis, eosinophilic plaque and eosinophilic granuloma.

Body areas most commonly affected by feline dermatitis:

  • Ears;
  • Muzzle;
  • Around their eyes;
  • In between their toes;
  • Underarms;
  • Ventral chest and abdomen;
  • Groin;
  • Perianal region;
  • Wrists;
  • Ankles.

What can cause cat dermatitis?


1. Flea allergy dermatitis (FAD)

Flea allergic dermatitis (FAD) is one of the most common causes for allergies in cats (that are allowed to go outdoors). In this case, the cat can become allergic to a component of flea saliva, and develop an intense allergic reaction when bitten.Even a single bite. can be enough to make the cats` skin extremely itchy. Usually, fleas prefer the area right at the base of the tail and even if it might be funny to watch a cat butt go up in the air when someone is scratching his/her back on that particular spot, keep in mind that excessive itchiness in that area can mean that your cat has fleas.

Monthly flea prevention is very important to prevent flea bites! Ask your vet!


2. Food allergy dermatitis

Did you know that your cat can eat the same food for years, and then, out of nowhere, they can develop an allergy to that food? Food allergies in cats are extremely common. When your pet is dealing with a food allergy, their skin and coat will be the most affected.


This allergy can begin when a cat is allergic to a specific protein that can be found in the regular food. Food allergies can develop at any point in life, even if your cat has been eating the same food for years with no issues.

Food allergies are not as common as flea and environmental allergies. If we want to get accurate results for your cat, we need to do a food trial and this means that your cat must only eat the special prescription diet for the duration of the trial.

No other food, no treats, no table food and no flavored medications. If your cat’s skin will improve with a specific diet, then a food allergy is usually the cause of the cat’s dermatitis. All you have to do is to keep your cat on the prescription diet and that should solve your and your cat’s problems.

Important nutrients that can help heal and protect your cat’s skin:

✔ Essential Fatty Acids: A cat food containing high levels of omega-3 and omega-6 fatty acids, found naturally in fish oil. This will help nourish and protect your cat’s skin, prevent dryness and help control inflammation.

✔ Antioxidants: Vitamin E and other antioxidants are vital in maintaining your cat’s immune system in a healthy state.

✔ Protein: High-quality protein provides the building blocks to repair damaged skin.


3. Atopic dermatitis

Atopic dermatitis (atopy) is an allergy to something in the environment (such as pollen, molds, grass or dust mites). 

With time, atopic dermatitis can become a serious health issue, if not treated in due time. Your cat`s skin can become extremely itchy, red, scaly and irritated. If your cat is not treated, there is a risk of hair loss, skin infections and ear infection.  As in canine atopic dermatitis, feline atopy usually seems to be caused by an exaggerated IgE and immunoglobulin G (IgG) response to environmental allergens!


Miliary dermatitis and eosinophilic granuloma complex are distinctive clinical patterns associated with feline atopy (not reported in dogs and humans). The whole palette of allergies can develop lesion patterns like these, even if they are not considered specific for atopy, these lesions are a generic manifestation of allergies in cats.

Eosinophilic granuloma complex lesions include indolent ulcer, eosinophilic granuloma, and eosinophilic plaque lesions. Eosinophilic plaques and indolent ulcers may also represent pyoderma .


4. Drug reactions

Compared to dogs, cats are generally more predisposed to developing drug reactions that affect their skin.

These are known as Cutaneous Adverse Drug Reactions, or ADR’s. ADR’s cannot be anticipated and occur after a normal dosage of medication is administered.

Every medication is a risk and we don’t understand why one individual has a hypersensitive response to a drug that most other individuals can tolerate very well, and we also can’t predict which individual will ultimately have a reaction.

Even so, we inform you about any risk and what to do in case of any allergic reaction is observed. Cutaneous ADR’s typically develop redness, intense itchiness, hives, and even blisters.

Most start with itchiness. You must call your veterinarian to discuss the possibility of a drug reaction if we`ve just given your cat a medication and you see lots of scratching at home.


5. Bacterial dermatitis

Pyoderma is a skin bacterial infection. Pyoderma can be divided into superficial pyoderma (infection within the skin) or deep pyoderma (infection under the skin). The most common bacteria causing pyoderma is Staphylococcus aureus.

Pruritus (itching) leads to self-trauma. That causes damage to the skin and breakdown of natural defense mechanisms. The resulting lacking natural defences allows bacteria to penetrate into the epidermis causing pyoderma. Examples are allergy and infestation of parasite like mites or lice.


When your cat’s skin is cut or wounded, the area surrounding the wound or the cut is more prone to infections .


Cats` can develop lesions and pustules (inflamed pus-filled swelling) on the skin, or even partial hair loss. Treatment is typically given at home and prognosis is good.


While any cat breed can be infected by this bacteria, some breeds are more predisposed to develop pyoderma, such as:

  • Short coats;
  • Skin folds.

Other higher risks for developing infections:

Fungal infection. Most common in domestic cats: Malassezia pachydermatis, Cutaneous sporotrichosis, Disseminated sporotrichosis, Rhinosporidiosis, Phaeohyphomycosis, Mycetomas, Cryptococcosis, Coccidioidomycosis, Candidiasis. Some skin infections can be treated with special antifungal creams or ointments or oral antifungal medications. Special shampoos or dips can treat other infections that are caused by yeasts.

Other fungal infection such as ringworm (more frequent);

Endocrine disease (hyperthyroidism);

Parasites (Demodex);

A viral infection such as cowpox.


6. Parasite allergy dermatitis

Otodectic mange. This means an infestation with ear mites. When there’s a mite infestation present we commonly call it “mange”. Cats can get the types of mange that dogs are famous for – including sarcoptic mange and demodectic mange. However, the most common type in cats is otodectic mange.

They are easily recognizable because ear mites produce thick, crusty brown debris inside the ear.

However, we should examine a sample of the debris under the microscope – usually the little parasites are easy to see . We also have to look for bacterial or fungal infections in addition to the mites because they are common in cases like this.

Treatment is antiparasitic, plus antibacterial, and/or antifungal if necessary. We may prescribe to you an otic solution to clean the year first and after that, a different otic solution that contains antibiotic and antifungal medication.


What can we do to treat dermatitis?

Diagnostic work-up:

✔ Diet elimination trial of 8 to 12 weeks (some patients may require multiple diet trials and possible restriction to indoor-only environment).

✔ Fleas prevention for a minimum of 8 weeks (including all other household pets and treating your house aswell).

✔ Avoid allergy triggers.

✔ Treatment for any secondary infections that may occur.

✔ Dermatophyte culture (if neccessary).

✔ Monitoring by the pet parent for any improvement that can be seen.

✔ Successful management, however, usually requires ongoing therapy!


Keep in mind!

▶ We use medical treatment to control the symptoms, not cure the allergy.

▶ Fleas alone are bad enough, but allergic cats are predisposed to developing allergies to fleas’ saliva.

▶ Disorders such as hyperthyroidism, diabetes, liver disease, and FIV or FeLV.

▶ Some underlying painful conditions, such as lower urinary tract disease, can cause cats to over-groom the area. This normally results in irritation and inflammation of the skin.

▶ Inability to self-groom properly due to obesity, arthritis, or dental disease.

▶ Sun damage, particularly in white cats and kitties with white ears, noses and eyelids.

⋆ These are just a few of the medications used so that you can have an idea of what we need to do!


Medical facts!

▶ Cats typically tolerate steroids better than dogs.

▶ Antihistamines don’t work that well by themselves.

▶ Allergen specific IgE can be determined via commercial serologic allergy tests, but you should know that serology does not distinguish between normal and atopic cats. There is a specific test, that you can do at your local vet clinic, which can actually tell us what specific protein or environmental stimulus/stimuli your cat is allergic to, but it is very expensive (normally @ £400-500).

▶ If corticosteroid therapy is continued beyond the stage of patient work-up, administration should be tapered down in time. Other systemic adverse effects include diabetes, urinary tract infection. and cardiac effect.

▶The immune-suppressing effects of the drugs prevent the body from reacting. However, they also cause increased susceptibility to infection and diseases.


Testing to identify specific substances that cause a reaction in a cat with allergies can provide extremely valuable information.

This can help pet parents and their cats avoid exposure to the resulting substances.No single diagnostic test is available that can reliably diagnose feline atopy.

There is, however, a suite of tests for that, but first we need historical information, clinical symptoms, and the exclusion of differential diagnoses.

♥ We will ask you to visit the vet practice at regular intervals to monitor your cat`s condition!

♥ In the mean time, take good care of your loved one! They deserve the best from us!

One thought on “Cats and Allergic Dermatitis. Everything you need to know!

Leave a Reply

Your email address will not be published. Required fields are marked *