Understanding Pannus in Dogs

You noticed something on your dog’s eye, a pinkish film creeping in from the corner, or a haze where there used to be clear cornea, and your vet said the word “pannus.” Also called chronic superficial keratitis, pannus is an immune-mediated condition where the body mistakenly attacks the cornea (the clear outer surface of the eye), causing a pink or grayish film to spread that can lead to permanent vision loss if left untreated. It’s manageable, but it does need attention, and the sooner treatment starts, the better the outcome.

What does pannus look like in dogs?

Pannus almost always starts at the outer edge or the lower portion of the cornea and works its way inward. What you’ll typically see:

• A pinkish or reddish film, almost like a curtain being slowly drawn across the eye
• A grayish or brownish pigmented patch that grows over time
• Blood vessels visibly spreading across the cornea (the clear part of the eye)
• A dull or hazy appearance instead of the usual clear surface
• In some cases, involvement of the third eyelid (the small membrane tucked in the inner corner of the eye) which can become thickened or depigmented

Pannus is typically not painful, which is actually part of what makes it tricky, your dog may seem totally unbothered while the condition quietly progresses. Squinting, discharge, or obvious discomfort aren’t usually the early signs here. The eye just starts looking different.

What causes pannus in dogs?

The root cause is immune-mediated, meaning the immune system gets confused and starts treating the cornea like a threat. Exactly why this happens isn’t fully understood, but a few factors are clearly at play:

• Genetics and breed. German Shepherds are by far the most commonly affected breed. Belgian Tervurens, Greyhounds, Border Collies, and Siberian Huskies also have higher rates. If your dog is a Shepherd mix, that genetic predisposition can carry through.
• UV exposure. Ultraviolet light is a well-established trigger. Dogs who spend a lot of time outdoors in bright sunlight, especially in open terrain without shade, tend to have more aggressive progression.
• High altitude. UV radiation increases with elevation, so dogs living or spending time at high altitude are at greater risk of faster progression. This is a genuinely underappreciated factor.
• Atypical pannus. Some dogs develop a variant called atypical pannus, which primarily affects the third eyelid rather than the cornea itself. It’s less common and can look a little different, but the underlying immune-mediated mechanism is the same.

How vets diagnose pannus

Diagnosis is usually made by a veterinarian or a veterinary ophthalmologist (a vet who specializes in eye conditions) based on the dog’s appearance, breed, and a hands-on eye exam. A few specific tests help confirm the picture:

• Fluorescein stain: A bright orange dye is applied to the eye surface. Under a special blue light, it highlights any damage or ulcers on the cornea. This rules out other conditions that can look similar.
• Schirmer tear test: A tiny strip of paper is gently placed at the edge of the eye for 60 seconds to measure how much tear fluid is being produced. This checks for dry eye, which can sometimes occur alongside pannus.
• Tonometry: A quick, painless measurement of eye pressure. This is done to screen for glaucoma (a condition where pressure inside the eye builds up) since it can look similar or occur at the same time.

If the presentation is unusual, your vet may refer you to a veterinary ophthalmologist for a more detailed evaluation. That’s not a bad thing, specialists have equipment that gives a much clearer view of what’s happening at the corneal level.

Treatment for pannus in dogs

There’s no cure for pannus, but treatment controls it effectively in most dogs. The goal is to calm the immune response at the eye’s surface and stop the film from spreading. Treatment is lifelong, this isn’t something you do for a few weeks and stop.

Topical eye drops (the mainstay of treatment)

• Cyclosporine eye drops or ointment: This is typically the first-line treatment. Cyclosporine is an immunosuppressant – it dials down the immune response specifically at the eye surface without suppressing the whole immune system.
• Tacrolimus eye drops: Another immunosuppressant, often used when cyclosporine alone isn’t providing enough control. Some dogs respond better to tacrolimus, and your vet may try one or the other, or both.
• Corticosteroid eye drops (like prednisolone): These anti-inflammatory drops are sometimes added during flare-ups or to get initial control, then tapered down. They’re effective but used carefully to avoid long-term side effects on the eye.

Other treatment options

• Subconjunctival injections: In some cases, a vet injects corticosteroids directly under the thin membrane covering the white of the eye. This is typically reserved for dogs who aren’t responding well to drops alone.
• Surgery: Rarely needed, but in cases of severe corneal scarring (permanent clouding from long-standing inflammation), a veterinary ophthalmologist may discuss surgical options to improve vision.

Most dogs do well on drops alone when treatment starts early. The longer pannus goes unmanaged, the more corneal scarring can accumulate, and scarring doesn’t reverse. That’s why early action matters so much.

Living with pannus day to day

Managing pannus isn’t just about drops, it’s about building a daily routine that reduces your dog’s UV exposure and keeps the condition as stable as possible.

Reducing UV exposure

• Time your walks strategically. Early morning and late afternoon walks avoid peak UV hours (roughly 10am to 4pm). This is especially important in summer and at higher elevations.
• Stick to shaded routes. Parks with tree cover, shaded trails, or urban blocks with tall buildings are genuinely better for a dog with pannus than open fields on a sunny day.
• Consider dog sunglasses (Doggles). Yes, they look goofy. They also work. UV-blocking dog goggles are a real tool recommended by veterinary ophthalmologists for dogs with pannus. It takes a few sessions to get your dog comfortable wearing them, but most dogs adjust with positive reinforcement and patience.
• Be mindful of altitude. If you’re planning a mountain camping trip or a move to a higher-elevation city, let your vet know. Your dog’s treatment plan may need to be adjusted for increased UV intensity.

Building a consistent eye-drop routine

• Administer drops at the same times each day, consistency matters more than the specific hour.
• Keep the drops in a visible spot (next to your coffee maker, for example) so they’re part of your existing routine.
• Use a treat or short play session after each drop application so your dog builds a positive association.
• If your dog resists drops, ask your vet about ointment formulations. Some dogs tolerate those more easily.

Vet follow-up cadence

Once the condition is stable, most dogs with pannus are rechecked every three to six months. If there’s a flare-up, you notice the film spreading, new redness, or your dog starts squinting, don’t wait for the scheduled appointment. Call your vet.

Is pannus covered by pet insurance?

Pannus is a lifelong condition with ongoing medication costs, and specialist visits to a veterinary ophthalmologist aren’t cheap. That’s exactly the kind of expense where pet insurance can make a real difference.

Lemonade’s pet accident and illness insurance is designed to help cover the cost of diagnosing and treating conditions like pannus (including eligible treatments, diagnostics, and medications) as long as the condition isn’t pre-existing at the time you enroll, and occurs once you’ve passed your waiting periods. That last part is important: once your dog is diagnosed with pannus, it becomes a pre-existing condition and won’t be covered by a new policy going forward.

If your dog is a German Shepherd, a Belgian Tervuren, or any other breed with a higher risk of pannus, enrolling before any diagnosis shows up is the move. It’s not about predicting the worst, it’s about being ready if it happens.

Before we go

Finding out your dog has pannus is a lot to take in, especially if you didn’t see it coming. But here’s where things actually stand: pannus is controllable. Dogs on consistent treatment, and with owners who’ve dialed in the UV-reduction habits, often go years with minimal progression. The cornea won’t fully clear, and there’s no cure, but blindness from pannus is largely preventable when you stay on top of it. Get to your vet, start treatment early, and build the daily routine that makes this manageable long-term. Your dog is lucky to have someone paying attention.

Frequently Asked Questions

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