Pannus in Dogs: Chronic Superficial Keratitis
- Pannus, also called chronic superficial keratitis, is an immune-mediated disease where blood vessels, inflammatory tissue, pigment, and scarring grow across the cornea and can reduce vision over time.
- It is seen most often in German Shepherd Dogs and related breeds, usually affects both eyes, and tends to worsen with ultraviolet light exposure and at higher altitudes.
- Most dogs are managed with lifelong topical medications such as cyclosporine or tacrolimus, often paired with a steroid eye drop during flare-ups or at the start of treatment.
- Pannus is usually controllable but not curable. Early treatment and steady follow-up with your vet help preserve vision and reduce permanent corneal pigmentation.
What Is Pannus?
Pannus, or chronic superficial keratitis (CSK), is a long-term inflammatory disease of the cornea, the clear front surface of the eye. In affected dogs, the immune system targets corneal tissue, leading to new blood vessel growth, pink fleshy inflammation, dark pigment, and scarring. Over time, that clear window becomes cloudy or opaque.
The condition usually starts at the outer edge of the cornea and slowly spreads inward. It often affects both eyes, although one eye may look worse. Many dogs are not obviously painful early on, so pet parents may first notice a pink film, a brown patch, or a hazy look rather than squinting or rubbing.
Without treatment, pannus tends to progress and can eventually interfere with vision enough to cause functional blindness. The good news is that many dogs do well with lifelong management. Treatment does not remove the underlying tendency, but it can slow or stop progression and sometimes improve the cornea’s appearance.
A related problem called plasmoma can affect the third eyelid. This may look like a thickened, pale, or cobblestoned third eyelid and often occurs alongside corneal pannus.
Signs of Pannus in Dogs
- Pink or red tissue creeping in from the edge of the cornea, often starting on the outer side of the eye
- Fine blood vessels growing across the normally clear cornea
- Brown, gray, or black pigment developing on the cornea as the disease becomes more chronic
- Cloudy, hazy, or scarred appearance of the eye surface
- Both eyes affected, but one eye may look more advanced
- Mild mucus or stringy eye discharge
- Thickened, inflamed, or depigmented third eyelid changes consistent with plasmoma
- Vision changes in advanced cases, such as hesitation on stairs, bumping into objects, or trouble in dim light
Pannus is often not dramatically painful, especially early on, which can make it easy to miss. Still, any new pink tissue, dark pigment, or cloudiness on the cornea deserves a prompt eye exam. See your vet sooner if your dog is squinting, rubbing the eye, has heavy discharge, or seems to be losing vision, because those signs can also happen with ulcers or other eye diseases that need different treatment.
What Causes Pannus?
Pannus is considered an immune-mediated eye disease. That means the body’s immune response targets the cornea and nearby tissues, causing chronic inflammation. The exact trigger is not fully understood, but genetics clearly matter.
German Shepherd Dogs are the breed most commonly associated with pannus, and Belgian shepherd breeds are also overrepresented. Border Collies, Greyhounds, and mixed-breed dogs can be affected too. Cornell’s canine genetics program describes pannus as an immune-related disease and is actively studying inherited risk in German Shepherd Dogs and Belgian shepherd breeds.
Environment also plays a role. Ultraviolet light can make pannus worse, and dogs living at higher altitudes often have more aggressive disease. Younger dogs diagnosed with pannus may also have a tougher course and need more intensive long-term control.
Pannus is not contagious, and it is not caused by a tumor, a dietary issue, or poor hygiene. It is also different from dry eye, corneal ulcers, and infections, although those problems can sometimes look similar at first glance.
How Is Pannus Diagnosed?
Your vet usually diagnoses pannus based on breed, history, and the eye’s appearance during an ophthalmic exam. The classic pattern is a nonpainful pink, vascular lesion starting at the corneal edge and spreading inward, often in both eyes. As disease advances, pigment and scarring become more obvious.
Testing is still important because other eye problems can mimic pannus. Your vet may use fluorescein stain to look for a corneal ulcer before prescribing steroid drops, measure intraocular pressure to screen for glaucoma, and perform tear testing if dry eye is a concern. Some dogs also benefit from corneal or conjunctival sampling when the diagnosis is less straightforward.
If the case is severe, atypical, or not responding as expected, referral to a veterinary ophthalmologist is a practical next step. A specialist can confirm the diagnosis, assess third eyelid involvement, and tailor a medication plan to your dog’s disease severity, lifestyle, and UV exposure.
Treatment Options for Pannus
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Primary-Care Medical Management
- Office exam with fluorescein stain and basic eye testing as needed
- Topical corticosteroid such as prednisolone acetate 1% or dexamethasone 0.1% started more frequently, then tapered
- Topical immunomodulator if available through your clinic or a prescription pharmacy, often cyclosporine 0.2% ointment
- Home monitoring for increased pigment, redness, discharge, or vision changes
- Lifestyle changes to reduce UV exposure, including shade and avoiding peak sun hours
Combination Therapy With Ongoing Monitoring
- Veterinary ophthalmology or experienced primary-care eye workup
- Combination topical therapy, commonly cyclosporine or tacrolimus plus a steroid eye drop
- Medication schedule tailored to severity, season, and response
- Evaluation and treatment of concurrent plasmoma or dry eye if present
- Rechecks every 4 to 8 weeks initially, then every 3 to 6 months once stable
- UV protection plan, which may include canine goggles for dogs that tolerate them
Specialist-Level Refractory or Vision-Restoring Care
- Board-certified ophthalmology management for severe or poorly controlled disease
- Subconjunctival steroid injection in selected cases
- Compounded higher-potency tacrolimus or cyclosporine protocols when standard therapy is not enough
- Superficial keratectomy to remove dense pigment or scar tissue that is blocking vision in selected dogs
- Anesthesia, surgical monitoring, and post-procedure rechecks
- Continued lifelong topical therapy after procedures to reduce recurrence
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Pannus
Bring these questions to your vet appointment to get the most out of your visit.
- You can ask your vet how advanced the pannus is in each eye and whether there is already permanent pigment or scarring.
- You can ask your vet whether cyclosporine, tacrolimus, a steroid eye drop, or a combination makes the most sense for your dog’s stage of disease.
- You can ask your vet how often the drops should be given now, and what signs would mean the schedule needs to change.
- You can ask your vet whether your dog also has plasmoma, dry eye, or another eye condition that could affect treatment.
- You can ask your vet how often rechecks are needed during the first few months and after the disease is stable.
- You can ask your vet whether UV reduction could help in your dog’s case and if canine goggles are realistic for your dog’s lifestyle.
- You can ask your vet what side effects to watch for with steroid eye drops, especially if a corneal ulcer is ever suspected.
- You can ask your vet when referral to a veterinary ophthalmologist would be helpful.
Managing Pannus Long-Term
Pannus is usually a lifelong management condition, not a one-time treatment. The biggest reason dogs lose ground is inconsistent medication. Even when the eyes look much better, the underlying immune process is still there. Stopping treatment often allows inflammation and pigment to return.
Most dogs start with more frequent drops, then move to the lowest schedule that keeps the disease controlled. Your vet may adjust the plan seasonally, especially in spring and summer when UV exposure is higher. Rechecks matter because small changes in the cornea can be easier for your vet to spot than for a pet parent at home.
UV reduction can help some dogs. That may mean more shade, avoiding the brightest midday sun, and trying UV-blocking dog goggles if your dog tolerates them. Dogs living at high altitude or spending long hours outdoors often need closer monitoring and sometimes stronger treatment.
The long-term outlook is often encouraging. Many dogs keep useful vision for years with steady care. Early treatment gives the best chance of limiting permanent pigment and scarring, so it is worth acting promptly when you first notice a pink, cloudy, or dark patch on the eye.