A cat presents with a black or brown spot on the cornea. What is the most likely diagnosis?

A cat presents with a black or brown spot on the cornea. What is the most likely diagnosis?

• A. Feline herpesvirus keratitis
• B. Corneal ulceration due to trauma
• C. Glaucoma
• D. Corneal sequestration & keratitis

Answer: (D)

A dark, pigmented patch on the cornea in a cat is most consistent with corneal sequestration. This condition occurs when corneal tissue becomes necrotic and forms a sequestrum that appears as a black or dark brown spot with a distinct border. It’s a characteristic presentation in cats and stands out from other corneal diseases because the pigmentation is the primary feature, rather than an active epithelial defect or corneal edema. In feline herpesvirus keratitis, you’d typically see dendritic epithelial ulcers that stain with fluorescein, not a dark pigmented patch. Trauma-related corneal ulcers present as an epithelial defect with pain and fluorescein uptake, again without a pigmented lesion. Glaucoma causes a painful, blue/gray, or hazy cornea due to edema and elevated intraocular pressure, not a discrete dark spot. Treatment focuses on removing the sequestrated tissue and addressing underlying inflammation, often with surgical keratectomy and ongoing medical management to protect the remaining cornea and prevent recurrence.

A dark, pigmented patch on the cornea in a cat is most consistent with corneal sequestration. This condition occurs when corneal tissue becomes necrotic and forms a sequestrum that appears as a black or dark brown spot with a distinct border. It’s a characteristic presentation in cats and stands out from other corneal diseases because the pigmentation is the primary feature, rather than an active epithelial defect or corneal edema.

In feline herpesvirus keratitis, you’d typically see dendritic epithelial ulcers that stain with fluorescein, not a dark pigmented patch. Trauma-related corneal ulcers present as an epithelial defect with pain and fluorescein uptake, again without a pigmented lesion. Glaucoma causes a painful, blue/gray, or hazy cornea due to edema and elevated intraocular pressure, not a discrete dark spot.

Treatment focuses on removing the sequestrated tissue and addressing underlying inflammation, often with surgical keratectomy and ongoing medical management to protect the remaining cornea and prevent recurrence.