Eosinophilic granuloma complex – what is causing the changes in my cat's mouth?

As the name suggests, this is not a separate disease, but rather a complex of various manifestations of inflammatory changes in the mouth and skin of cats.

INHALT
Cause and origin Forms and symptoms Diagnosis Therapy Forecast Prophylaxis
Cause and origin

The exact causes of this complex of symptoms remain unclear. It is suspected that an excessive reaction of the immune system to a specific allergen (a substance recognized by the immune system as foreign) triggers the skin or mucous membrane reaction. This may be an actual external allergen, such as flea saliva or a food ingredient, or the body may react to an allergen produced by the body itself without any apparent cause. This is referred to as an idiopathic immune reaction.

However, parasitic, bacterial, and viral diseases, as well as hereditary factors and other causes of eosinophilic granuloma complex, are also being discussed.

Regardless of the type of allergen, the same defense reaction always occurs in the body. To combat the allergen, more eosinophils (certain white blood cells) are produced and sent to the affected areas of the skin. Normally, the cells do their job and the inflammation heals. However, if there is an excessive reaction of the eosinophils, the inflammation spreads to other layers of the skin, accompanied by severe itching. The cats begin to constantly lick the affected areas, which further aggravates the inflammation until raised, ulcerated lesions develop.

Forms and symptoms

Eosinophilic ulcer

This slightly weeping, ulcerated skin lesion, also known as a painless ulcer, occurs on one or both sides of the cat's upper lip in the area of the canine tooth. Irritation caused by the canine tooth or tongue is thought to trigger this change, although allergic reactions to fleas or food are also suspected. The inflammation is not accompanied by pain or itching, but can reach considerable proportions due to constant licking with the tongue.

Eosinophilic ulcers can sometimes resolve on their own, but if they persist for a long time, they can also develop into tumors.

Eosinophilic plaque

These are round, raised, reddened, intensely itchy, and weeping areas of skin that occur particularly on the abdomen, inner thighs, and sometimes on the head or neck. Here, too, most of the inflammation develops as a result of licking with the tongue, which is why most of these changes occur in areas that the cat can reach with its tongue. Secondary bacterial infections lead to further aggravation of the inflammation, which often requires lengthy treatment.

Eosinophilic granuloma

A granuloma is when the collagen layer (connective tissue) of the skin is destroyed or damaged and nodule-like changes form. These changes can appear as an elongated strand (linear granuloma) on the front or hind legs or as numerous yellowish nodular changes in the cat's mouth. In the mouth, these nodules are often found on the back of the tongue and in the palate. They are extremely painful and affected cats often suddenly stop eating or salivate profusely.

Cat with eosinophilic granuloma
Nodular growths in a cat's mouth
Diagnosis

Your veterinarian will make an initial diagnosis based on the very characteristic appearance of this complex of diseases. A blood count will provide further important information about any changes in cell counts. However, in order to definitively diagnose eosinophilic granuloma complex, a histological examination of a skin sample is essential.

Cat with pain in its mouth
Therapy

The earlier treatment begins, the better the chances of recovery. Therefore, take your cat to the vet even if you notice only minor skin changes. When it comes to treatment, any underlying conditions or allergies should always be ruled out first or treated if present.

The actual treatment of the skin lesions depends on the extent and severity of the changes and can sometimes be very time-consuming and require intensive care. Since secondary bacterial infections are involved in most cases, treatment is often started with antibiotic preparations. Anti-inflammatory drugs, painkillers, or immunosuppressive drugs are also used depending on the severity. Surgical removal or laser therapy may be necessary for stubborn and recurring granulomas.

Forecast

The various skin changes usually respond well to drug therapy, but relapses are relatively common, which is why it is not always possible to speak of a complete cure.

Prophylaxis

Due to the unclear causes of eosinophilic granuloma complex, effective prevention is not possible. However, parasite prevention is essential to minimize the risk of developing the disease. Successfully preventing flea or other parasite infestations can significantly reduce excessive grooming and licking in cats.