What Is Chronic Superficial Keratitis?
Chronic superficial keratitis (CSK), better known as pannus, is an immune-mediated disease of the cornea, the clear front window of the eye. The immune system targets the cornea, and pink, fleshy tissue with blood vessels slowly creeps across its surface, usually starting at the outer edge. Over time the area often darkens with pigment, which can block vision.
Pannus most often affects German Shepherds and their crosses, along with Belgian Tervurens, Greyhounds, Border Collies, and Dachshunds. Ultraviolet (UV) light makes it worse, so dogs living at high altitude or in very sunny parts of the US tend to have more severe disease. It usually affects both eyes.
Why it matters
Pannus is usually not painful, so owners often miss it until the cornea is cloudy or pigmented. It cannot be cured, but daily treatment can protect vision for life.
Signs Owners Notice
- A pink or red film growing onto the eye from the outer corner
- Brown or black pigment spreading across the clear part of the eye
- Cloudiness or a grayish haze on the cornea
- Thickened, depigmented, or pink third eyelids (a related form sometimes called plasmoma)
- Bumping into things or reluctance in bright light as vision declines
Diagnosis
Your vet diagnoses pannus by its typical look and breed pattern during an eye exam. They will usually run a tear test and a fluorescein stain to rule out dry eye (KCS) and a corneal ulcer, which look different and are often painful. Pressure checks help exclude glaucoma and uveitis. A veterinary ophthalmologist may be involved for advanced or tricky cases.
Treatment and Outlook
- Immune-suppressing eye drops: cyclosporine or tacrolimus to calm the immune reaction.
- Steroid eye drops or ointment: used to shrink active pannus, often more often at the start and then tapered.
- UV protection: dog sunglasses or goggles and avoiding midday sun help reduce flare-ups.
- Injections or surgery: occasionally used for stubborn cases, but drops remain the mainstay.
With consistent treatment, most dogs keep useful vision. Treatment is lifelong, and the disease often flares in summer or if drops are stopped. Some pigment may stay even when the condition is controlled.
Practical Tips for US Pet Owners
- Never stop eye drops without your vet’s advice, even if the eyes look better.
- Expect to increase treatment in spring and summer, or at higher elevations.
- If you have a German Shepherd, read our German Shepherd breed guide and ask about eye checks at annual visits. See also dog eye care.
- Find a nearby practice through veterinary clinic listings.
When to see a vet
Book a visit if you see pink tissue or dark pigment spreading onto your dog’s eye. Go sooner if the eye is red, squinting, or painful, since that points to a different problem.
Key Takeaways
- Pannus is an immune-mediated corneal disease, common in German Shepherds.
- UV light and altitude make it worse.
- Lifelong eye drops and sun protection usually preserve vision.
FAQ
Is pannus painful for dogs?
Usually not. That is why it often goes unnoticed until the cornea is cloudy or pigmented.
Can pannus be cured?
No, but it can be controlled. Most dogs need eye drops for life.
Do dog sunglasses really help pannus?
Yes. UV-blocking goggles reduce the light exposure that drives flare-ups and are a common add-on to medicine.