Wrinkles has been off and on squinting his left eye for a month with a brown spot appearing out of nowhere! My vet says he hasn’t seen anything like this before. Is this cancer?
Thank you for writing! Wrinkles looks to have a corneal sequestrum. This is a poorly understood condition related to breed predisposition (Persians), previous or active corneal irritation or ulceration, and feline herpes virus-1.
The jury is still out on why the sequestra take on a brown coloration, with discussion about iron and melanin being common. However, the site is known to be necrotic (ie. dead) tissue and frequently associated with discomfort, non-healing corneal ulcerations, and opportunistic bacterial or fungal infections. Although corneal sequestra are not cancerous, they do require treatment. Surgical removal of the sequestrum via superficial keratectomy by a veterinary ophthalmologist is usually a good treatment option. Surgical success exceeds 90%, but there is a modest chance of recurrence. For best results, I typically recommend addressing any known factors that may predispose to the development of corneal sequestra, like feline herpes virus-1 infection and entropion.