Corneal Sequestrum in Cats: Symptoms, Causes, and Treatment Options

If your cat is suddenly squinting, pawing at one eye, or showing signs of discomfort around bright light, you may assume it’s just a scratch or a bit of dust. But if you look closer and notice a dark, discolored spot on the eye—especially one that seems to be getting worse—it could be something more serious. At Veterinary Vision Center in Shreveport, Louisiana, we frequently see a condition unique to cats known as corneal sequestrum, and we’re here to help you understand what it is, what causes it, and how it can be treated.

What Is a Corneal Sequestrum?

A corneal sequestrum is a localized area of dead or dying corneal tissue that turns dark brown or black. It typically appears as a central or paracentral lesion on the surface of the eye and is often surrounded by inflammation or ulceration. This condition is almost exclusively seen in cats.

The American College of Veterinary Ophthalmologists (ACVO) describes a sequestrum as a breakdown of corneal tissue due to chronic irritation or injury, which the cat’s body then tries to reject. Over time, the affected corneal tissue darkens and can cause ongoing pain, corneal ulcers, or even vision loss if untreated. Learn more and see images from the ACVO.

What Causes Corneal Sequestrum in Cats?

There’s no single cause, but rather a combination of predisposing factors that increase a cat’s risk. These include:

  • Chronic eye irritation
  • Previous or unresolved corneal ulcers
  • Feline herpesvirus (FHV-1)
  • Entropion (inward-turning eyelids)
  • Breed predisposition, especially flat-faced cats like Persians and Himalayans

Brachycephalic (flat-faced) breeds often have shallow eye sockets, which can lead to increased exposure and irritation of the eye surface. These cats are more vulnerable to environmental debris, dry eye, and trauma.

Chronic feline upper respiratory infections, particularly those associated with feline herpesvirus, can also contribute to recurring eye inflammation. ASPCA Pro explains how FHV-1 can cause conjunctivitis, corneal ulcers, and long-term ocular complications—all of which increase the risk for sequestrum formation.

How Can You Recognize a Corneal Sequestrum?

This is not a condition that usually sneaks by unnoticed, especially if you’re keeping a close eye on your cat’s behavior and comfort.

Signs of a corneal sequestrum may include:

  • A dark brown or black spot on the eye surface
  • Squinting or holding the eye partially closed
  • Pawing at the eye
  • Discharge or excessive tearing
  • Sensitivity to light
  • Cloudiness or a bluish haze around the lesion
  • Reluctance to be touched around the face

If you’re seeing any of these signs, it’s time to schedule an evaluation. Prompt diagnosis is key to preventing further damage and discomfort. Our team at Veterinary Vision Center is highly experienced in diagnosing and managing corneal disease in cats, including surgical and non-surgical options for sequestra.

Diagnosis and Diagnostic Tools

During your visit to Veterinary Vision Center, we’ll perform a thorough ophthalmic exam, which may include:

  • Slit-lamp biomicroscopy to assess the depth and characteristics of the lesion
  • Fluorescein staining to evaluate for concurrent corneal ulcers
  • Schirmer tear testing to check for dry eye
  • Tonometry to rule out glaucoma or increased intraocular pressure

Our goal is to not only confirm the diagnosis but also identify any underlying causes, such as viral infections or eyelid abnormalities.

Treatment Options for Corneal Sequestrum

Treatment depends on the severity and progression of the lesion. In some mild cases, especially if the sequestrum is superficial and the cat is comfortable, medical management with antiviral, antibiotic, and lubricating eye drops may allow the sequestrum to slough naturally over time. That said, this approach requires close monitoring and can take months.

In most moderate to severe cases, however, the preferred treatment is surgical removal of the sequestrum. The procedure, known as a keratectomy, involves carefully removing the dead tissue to allow healthy cornea to heal.

Some cats may also benefit from the use of a conjunctival graft or other forms of tissue support, especially if the cornea is deeply ulcerated or at risk of perforation.

After surgery, we typically prescribe:

  • Topical antibiotics and anti-inflammatory drops
  • Pain control medications
  • Protective collar use
  • Frequent follow-up visits to monitor healing

If your cat has never received eye medication before, we understand this can feel intimidating. Fortunately, Cornell University provides excellent guidance on how to administer eye medications safely and effectively at home.

Can a Corneal Sequestrum Come Back?

Recurrence is possible, especially if the underlying cause—such as herpesvirus or entropion—is not addressed. That’s why a full ophthalmic workup is so important. Managing chronic eye inflammation and protecting the cornea long-term can help reduce the chance of future issues.

We also work closely with your primary care veterinarian to coordinate follow-up care and long-term management of predisposing conditions.

Why Specialized Veterinary Ophthalmology Matters

Ocular diseases like corneal sequestrum require precision diagnostics and treatment planning that go beyond general practice. At Veterinary Vision Center in Shreveport, our focus is 100% ophthalmology, and our team brings years of advanced training and technology to every exam room.

Learn more about our dedicated ophthalmology services, and come see us at Veterinary Vision.

Common Questions About Corneal Sequestrum

Is a corneal sequestrum painful?

Yes. Even small lesions can cause significant discomfort. Left untreated, pain and vision loss are common outcomes.

Will my cat need surgery?

Possibly. Surgical removal is often the most efficient and definitive treatment, especially for deeper or chronic sequestra.

Can this be prevented?

While not always preventable, managing chronic eye problems, using antiviral medications when needed, and protecting vulnerable breeds (like Persians) from trauma or environmental irritants can reduce risk.

Let’s Keep an Eye on Things

Corneal sequestrum may be unique to cats, but it’s a condition that requires serious attention and expert care. If you’ve noticed changes in your cat’s eye appearance or behavior, don’t wait—vision problems progress quickly, and early intervention can preserve both comfort and sight.

At Veterinary Vision Center, we’re proud to serve Shreveport, Louisiana, and beyond as a trusted referral center for feline eye health. Schedule a consultation today.
Your cat’s eyes have a lot to say—let us help them stay bright, clear, and pain-free.