Eosinophilic Keratitis in Cats: Symptoms, Causes, and Treatment

Published Jan. 15, 2025
eosinophilic keratitis in cats; a cat with large eyes.

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In This Article

Summary

Eosinophilic keratitis in cats typically only affects one eye, but in rare cases it can affect both. Any age or breed of cat can be affected, but it is most common in cats who are around 5 years old.

This condition is not considered a medical emergency, but if left untreated, it can result in significant discomfort, corneal ulcers, and in rare cases, blindness.

Key Takeaways

  • Eosinophilic keratitis in cats causes inflammation within the cornea.
  • The cause of eosinophilic keratitis in cats is not known, but it’s thought there may be a connection between this condition and feline herpesvirus.
  • Since the underlying cause of eosinophilic keratitis in cats is unknown, it’s difficult to prevent this condition.

What Is Eosinophilic Keratitis in Cats?

Eosinophilic keratitis in cats is a condition that results in inflammation within the cornea, the front part of a feline’s eye. Keratitis is inflammation of the cornea while conjunctivitis is inflammation of the conjunctiva, the pink parts of the eye.

Keratitis occurs when inflamed cells spread across the cornea and conjunctiva, but the cause is unknown. Cats may experience troubling symptoms such as squinting, eye discharge, and eye pain.

If you notice an unusual appearance to your cat’s eyes or concerning symptoms, contact your veterinarian.

Symptoms of Eosinophilic Keratitis in Cats

Symptoms of eosinophilic keratitis in cats include:

Causes of Eosinophilic Keratitis in Cats

The cause of eosinophilic keratitis in cats is not known, but it’s thought there may be a connection between this condition and feline herpesvirus.

 There may also be an immune-mediated or allergic component to the disease. Any breed, age, or gender is equally likely to be affected by this condition.

How Veterinarians Diagnose Eosinophilic Keratitis in Cats

To diagnose eosinophilic keratitis in cats, a veterinarian will start with a complete physical exam. The vet will pay close attention to the cat’s eyes and note anything unusual or any concerning symptoms.

During this time, the pet parent should discuss when symptoms started, if their cat has any underlying medical conditions, and if there has been any trauma to the eyes recently.

If you notice an unusual appearance to your cat’s eyes or concerning symptoms, contact your veterinarian.

To rule out other causes of eye inflammation in cats, the veterinarian may perform the following tests first:

  • Fluorescein stain—A drop of bright green fluorescein stain is applied to the eye. A blue light is used to detect scratches or ulcers within the cornea that glow green.

  • Schirmer tear test—A small strip of paper is applied to the inside of the bottom eyelid to collect tears. If a certain number of tears is not present in a specific time frame, it may indicate underlying dry eye.

  • Tonometry—A special device called a tonometer is used to measure eye pressure, which could indicate glaucoma if pressures are high.

If your veterinarian notes concern with your cat’s cornea and conjunctiva, they will likely perform a cytology to confirm a diagnosis of eosinophilic keratitis.

During this test, a drop of topical anesthetic is applied to the affected eye or eyes.

A sample of cells from the cat’s cornea is collected, using a special type of brush or a dull scalpel blade.

The sample is added to a glass slide, stained, and viewed under a microscope to identify signs of inflammation.

Treatment of Eosinophilic Keratitis in Cats

Treatment for eosinophilic keratitis in cats consists of immunosuppressive medications to reduce pain and inflammation. These may include the following:

If a corneal ulcer is present, it must be healed prior to starting any topical steroids. A topical antibiotic, such as Terramycin, may be prescribed to help with healing and treat any secondary bacterial infections.

If your cat has been diagnosed with feline herpesvirus, an antiviral medication such as famciclovir may be needed for treatment.

Unfortunately, eosinophilic keratitis is typically not cured and must be managed long-term, especially if your cat has other underlying health issues.

Recovery and Management of Eosinophilic Keratitis in Cats

Eosinophilic keratitis in cats commonly recurs following treatment and typically requires long-term management to keep the eye inflammation under control.

Ensuring you give your cat the medications as prescribed by your veterinarian will help control symptoms and keep him comfortable.

Prevention of Eosinophilic Keratitis in Cats

Since the underlying cause of eosinophilic keratitis in cats is unknown, it’s difficult to prevent this condition.

However, pet parents should ensure their cats receive regular veterinary care to identify any health concerns early, so that necessary treatment can be discussed.

Eosinophilic Keratitis in Cats FAQs

What causes eosinophilic keratitis in cats?

The exact cause is unknown, but it may be related to underlying immune-mediated or allergic diseases, or feline herpesvirus.

What autoimmune disease causes keratitis?

Any autoimmune disease in cats can trigger keratitis, such as rheumatoid arthritis or lupus.

What is the difference between keratitis and conjunctivitis in cats?

Keratitis is inflammation of the cornea (the front layer of the eye), while conjunctivitis is inflammation of the conjunctiva (the pink parts of the eye).

References

Eosinophilic Keratoconjunctivitis in Cats - PubMed

Eosinophilic keratitis and keratoconjunctivitis in a 7-year-old domestic shorthaired cat - PMC

References


Brittany Kleszynski, DVM

WRITTEN BY

Brittany Kleszynski, DVM

Veterinarian

Dr. Brittany Kleszynski is a veterinarian and freelance medical writer who specializes in creating meaningful content that engages readers...


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