Eosinophilic disease is a very uncomfortable and treatable dermatological condition in cats. If you see signs of this disease, contact your veterinarian immediately.

Eosinophils are a type of white blood cell, which are an important part of the body’s immune response, assisting the body in fighting infection. Eosinophilic diseases occur when the eosinophils mistakenly release inflammatory chemicals that are meant to fight parasitic invasion when no parasites have actually infected the cat. This condition usually occurs as a result of a hypersensitive reaction to mosquito, flea or mite bites, medicine, or food, and causes severe symptoms of an allergic reaction such as itching, swelling, ulcers, oozing sores, bumps, and/or tumor-like growths.

As listed above, eosinophilic disease can come in three variations, which are eosinophilic ulcer, eosinophilic plaque, and eosinophilic granuloma. The symptoms of these versions of this disease are as follows:

There are three types of eosinophilic disease in cats. Cats can experience one, two, or all three of these forms of eosinophilic disease at the same time.

Eosinophilic ulcers usually present inside the mouth or on the top lip. 

Eosinophilic plaque manifests as inflamed hive-like bumps on the inner thighs and abdomen. 

Eosinophilic granuloma is by far the most common of the three conditions in cats. The condition causes large pinkish-yellow bumps that can appear as ulcers or tumors on the hind legs and/or in the mouth. 

The most common cause of the various forms of eosinophilic disease is a hypersensitive immune reaction to one of the following:

As is usually the case, your veterinarian will likely begin the appointment by asking you what symptoms you have observed as well as asking if there have been any recent changes in the cat’s diet. In addition, your vet will review your cat’s known medical history. After doing so, the vet will utilize some or all of the following diagnostic tools:

The most effective way to treat eosinophilic disease is to address the disease with a twofold approach. The vet will attempt to determine what is causing the hypersensitive reaction, and then remove your cat from the environment that causing it or remove the offending agent from your cat’s environment. This may be attempted through one or more of the following:

The vet will, usually at the same time, treat the secondary skin symptoms. Whether the underlying cause of the reaction can be determined, the following may be prescribed to help the cat’s skin condition to clear up:

A cat’s recovery from eosinophilic disease is highly dependent upon whether or not you and your vet can determine what has caused the hypersensitive reaction. If the underlying cause can be determined and that cause removed from the cat’s environment, a positive prognosis of complete recovery is highly likely. The pet owner will need to be vigilant in ensuring that this removal of the cause remains lasting and consistent. If the underlying cause cannot be determined, the short term prognosis may still be good with treatment, but the likelihood of recurrences of itching, ulcers, sores, and bumps is likely.