Feline Corneal Sequestrum: Diagnosis and Welfare Management

Corneal sequestrum is a painful and progressive eye condition unique to cats, characterised by a dark plaque on the cornea requiring careful management or surgery.

Key Facts

Corneal sequestrum is a necrotic area of stromal collagen that becomes dark brown to black.
The exact cause is unknown but chronic corneal irritation, herpesvirus infection, and entropion are risk factors.
Persian, Himalayan, Birman, and British Shorthair cats are predisposed due to facial conformation.
Affected cats typically show blepharospasm, excessive tearing, and visible dark corneal discolouration.
The condition is painful — the dark plaque may press on the cornea and cause chronic discomfort.
Treatment options include surgical keratectomy (removal of the sequestrum) or conservative management.
Surgery carries a recurrence risk of 15-25%, particularly if the underlying cause is not addressed.
Post-operative care requires careful application of eye medications and Elizabethan collar use.

Welfare Considerations

Corneal sequestrum causes chronic ocular pain that cats may mask through stoicism, making welfare assessment difficult. Undiagnosed or untreated sequestra can deepen, potentially perforating the cornea and causing permanent vision loss. Brachycephalic breeds face higher risk due to shallow orbits, abnormal eyelid conformation, and reduced blink reflexes — these anatomical issues require addressing alongside the sequestrum itself. Post-surgical recovery demands consistent owner commitment to eye medication protocols. Cats that develop recurrences face repeated procedures and chronic discomfort. Preventive management of herpesvirus in at-risk cats with L-lysine and antiviral medications may reduce recurrence rates.

What You Can Do

If your cat has a dark spot on their eye or shows squinting and tearing, seek veterinary assessment promptly.
Brachycephalic cat owners should schedule regular ophthalmic examinations.
Discuss surgical versus conservative management options with a veterinary ophthalmologist.
Follow post-operative medication schedules precisely to support healing and prevent infection.
Address underlying causes — treat herpesvirus, correct entropion — to reduce recurrence risk.
Consider selecting cats from breeding lines without extreme facial conformation to reduce inherent risk.