
Eosinophilic ulcer in cats (EoU) is a common skin condition. Although it can occur at any age, it is most commonly seen in cats between the ages of one and four years old. EoU is a self-limited skin disease that causes inflammation and granuloma formation around hair follicles. If not treated, EoU can lead to permanent damage to the skin and may require surgery. In this guide, we will provide you with all the information you need to know about EoU and how to treat it. We hope that this guide will help you to keep your cat healthy and happy!
Eosinophilic ulcer in cats can be a frustrating problem to eliminate. The lesion results from a localized invasion of a type of white blood cell called an EOSINOPHIL. A type of white blood cell found in vertebrate blood, containing cytoplasmic granules that are easily stained by eosin or other acid dyes, eosinophils often are associated with and invade tissues that are being physically irritated or are undergoing an allergic reaction. When large numbers of eosinophils locally invade the tissues they interfere with normal physiological processes and as a result scar tissue can form, microcirculation is impeded, and inflammatory cells migrate to the area in an attempt to heal the damage. Tissue destruction results in death of cells and, in the case of “rodent ulcer” in a cat, there can be a disfiguring ulceration of the upper lip. In severe cases the inside of the oral cavity and the lower lip may be involved.
Eosinophilic ulcer in Cats

Eosinophilic ulcer in cats often will reoccur. In many cases, low dose administration of cortisone or synthetic cortisone such as Dexamethasone can alleviate the severity of the ulcerative process. Some patients need to be treated for a short period of time every three or four months to keep the ulceration from becoming a problem for the cat. In all cases, a high quality diet with high levels of protein and good quality fats can put the patient at an advantage in keeping the ulcerative process from becoming clinically evident.
RODENT ULCER

Rodent Ulcer is actually a condition seen in humans where cancerous skin lesions occur. Usually these are a facial ulcer not actually having anything to do with rodents. Rodent ulcer in humans is a locally invasive carcinoma of the basal layer of the epidermis. It almost never metastasizes but it may aggressively invade local tissues. Basil cell carcinoma is a form of skin cancer that occurs due to sun exposure. Metastatic disease rarely occurs (does not spread to distant organs). This type of cancer can cause disfigurement to the skin and nearby structures. If left untreated for long periods, it has the potential to invade deep tissues.
The term “Rodent” ulcer in cats is actually not descriptive or relevant. At one time it was thought these ulcers were due or infections contracted from rodents. Although their real cause is still unknown, some veterinarians believe they result from constant irritation from the cat’s rough tongue.
When it comes to your cat’s health, be sure you give this guide a second glance. It is important that you take the right steps after reading this information and prevent your beloved feline from suffering an Eosinophilic ulcer. By maintaining a healthy diet and regularly checking your pet’s condition, you can achieve long-term relief.
Do not forget to share the content with any of your friends or family members who might not have access to a vet in case they accidentally overlook signs of illness in their cats. You can also consult us if you have any questions about proper nutrition for Eosinophilic ulcer in cats.
Frequently Asked Questions
What is a common feature in oral eosinophilic granuloma in cats?
These lesions most frequently manifest as ulcers on the lips, particularly the upper lip. Even though the phrase “rodent ulcers” is erroneous, it is commonly used to describe them. The lesions range in size from tiny, scarcely perceptible ulcers to massive, widespread ulcers that mar the lips.
Is feline eosinophilic granuloma painful?
Eosinophilic ulcers are well-defined, red, skin lesions that are typically neither painful or irritating. They are also known as “rodent ulcers” or indolent ulcers. They most frequently appear on the upper lip.
What causes low eosinophils in cats?
Eosinophils can build up in mouth sores or skin sores in some cats. Eosinopenia, also known as a decrease in eosinophils, can happen as a result of stress or corticosteroid therapy.