What is a corneal ulcer?
A corneal ulcer (ulcerative keratitis) is a loss of tissue from the transparent surface of the eye (cornea). It can affect only the superficial epithelium or penetrate into the deeper stroma and even Descemet's membrane (deep or perforating ulcer), with the risk of losing the eye.
Common causes
- Trauma: cat scratch, twig, foreign body.
- Trichiasis / distichiasis: hairs rubbing directly on the corneal surface.
- Dry eye (KCS): insufficient tear production β drying and ulceration.
- Entropion: inwardly rolled eyelid rubbing against the cornea.
- Infection: bacterial, viral or fungal.
- Spontaneous Chronic Corneal Epithelial Defects (SCCED / indolent ulcer): common in Boxers β the epithelium fails to adhere to the stroma.
Brachycephalic breeds (Bulldog, Pug, Shih Tzu, Pekingese) are especially prone due to their prominent eyes and reduced blink reflex.
Symptoms
- Blepharospasm (repeatedly squinting or closing the eye) and photophobia.
- Epiphora (excessive tearing).
- Pawing at the eye.
- Red eye with visible surface vessels.
- White opacity or spot visible on the cornea.
Diagnosis
- Fluorescein stain test: the green dye adheres to areas without epithelium β outlines the ulcer under blue light. Quick and painless.
- Depth assessment with a slit lamp.
- Schirmer tear test: rules out KCS.
Treatment
- Simple superficial ulcer: topical antibiotics (ointment or drops) + Elizabethan collar (essential β prevents rubbing).
- Deep or infected ulcer: intensive antibiotics, atropine drops, urgent referral to a veterinary ophthalmologist.
- Perforating ulcer: emergency surgery (conjunctival flap or keratoplasty).
- SCCED (indolent ulcer): epithelial debridement, grid keratotomy Β± conjunctival flap.
A corneal ulcer can worsen within hours. If your dog's eye is very red, kept shut or being frantically rubbed β see a vet the same day.