Two months ago, I noticed that my German Shepherd Dog, Karma, was having some issues with his left eye. Karma has an extremely high working drive, and it didn’t seem to interfere with his vision. I was concerned because of the color of his eye, and he was rubbing it a lot. I tried a warm, dampth cloth to hold over his eye. The next day, I took him to the vet.

I have an amazing veterinary team, and they were stumped also. So now we move up to the big leagues and visit an animal eyecare specialist, and I was about to learn more than I wanted to know.

Pannus, also known as Chronic Superficial Keratitis (CSK), is an autoimmune disease that affects the cornea (the clear) part of the eye and, left untreated, can eventually scar the eye so badly it can cause serious vision impairment or blindness.

OK, so what exactly is an autoimmune disease? Well, the purpose of your immune system (and a dog’s immune system) is to keep you healthy — it heals infections and tries to protect your body. But there are some diseases out there — in fact, more than 80 are currently known, that are referred to as autoimmune diseases. They essentially trick your immune system into attacking healthy cells by mistake — so instead of attacking bad cells, the immune system attacks normal, healthy cells instead. The immune system’s job is to track all of its healthy cells so it knows when something foreign comes into the body, but in the case of autoimmune diseases, the system glitches up, causing unintentional damage to healthy parts of the body.

Unfortunately, there’s no definitive answer for what causes autoimmune diseases. We’ll look at some of the potential causes as we go, but the official scientific answer at this point is that we don’t know why they occur.

So pannus/CSK is a progressive disease, but depending on a variety of factors such as genetics and UV exposure, it may progress at a slow or rapid rate, so you’ll want to identify and begin treating it as quickly as possible.

While you’ll most often hear of pannus being common in German shepherds, greyhounds, and a few other breeds due to a genetic predisposition, don’t assume your dog can’t get it. Pannus can occur in any breed and any size dog.

WHAT CAUSES PANNUS?

As previously mentioned, we don’t actually know what exactly causes autoimmune diseases. There is evidence that some breeds are genetically predisposed to developing pannus, such as German shepherds, border collies, and greyhounds, among others. 

Vets and scientists alike agree that increased exposure to UV rays makes the disease worse and could be an initiating factor in the disease. Dogs living at higher altitudes tend to be more susceptible to the disease due to the increase in UV exposure. 

There are also studies that suggest environmental allergens may cause a type of allergic reaction with some dogs’ corneas. In addition, there are some holistic practitioners that treat pannus through diet, suggesting there could be a tie between food allergies and the progression of the disease, though this has not been scientifically proven.

HOW DO I IDENTIFY PANNUS IN MY DOG?

Although it’s helpful to be able to identify or at least suspect pannus to be the diagnosis of your dogs’ eye condition, the only way to be sure is to seek professional care through a vet or veterinary opthamologist. Pannus can easily be confused with other eye problems such as Keratoconjunctivitis (also known as “dry eye”).

There are some common signs that you can look for in your dog that may point to a pannus diagnosis. Because the disease affects the cornea, there is usually a change in pigmentation where a cloudiness will develop and often contain visible blood vessels. With pannus, this change usually begins at the outside of the cornea, moving inward. Looking at a dog’s face and imagining their eye as a clock, these changes will most often be noticeable at the 3 o’clock and 9 o’clock positions.

If you didn’t already know, dogs have a third eyelid (we humans only have two) that serves multiple purposes from clearing mucus off the cornea to protecting the cornea to producing a third of dogs’ tears. Looking closely at your dog’s eye, you’ll see this third eyelid in the bottom corner of the eye (see below, picture taken from http://www.animalplanet.com/pets/healthy-pets/why-do-dogs-have-a-third-eyelid/).

 “Reddening, thickening, and pigment loss of the third eyelid characterize a subclass of CSK [pannus], called plasmoma.” Excessive mucus discharge from the eye may be a sign that your dog has plasmoma, so again, get it checked out by a professional.

Be especially diligent about checking your dog for any of these symptoms during the summertime or if your pup spends a lot of time outdoors. 

Dogs that live and play at higher altitudes should also be monitored carefully.  Dogs that live or spend time outdoors above a few thousand feet who develop pannus can be much more difficult to treat. This doesn’t mean you need to relocate to a lower altitude, but it does mean you may want to take additional precautions in addition to careful monitoring of your dog’s eyes.

Should you notice any of the symptoms we’ve mentioned above in your dog, schedule an appointment with your vet as soon as possible. Without treatment, the immune system will continue to attack the cornea to the point where scar tissue develops and can then lead to severe vision issues, including blindness.

WHAT ARE THE DIFFERENT TREATMENT OPTIONS?

There is no cure for pannus, but there are several ways to treat the condition.

• The most common treatment is through medications that keep the blood vessel growth and cloudiness under control. These anti-inflammatory medications commonly include corticosteroids, tacrolimus, or cyclosporine and are administered most often through eye drops, but can also be administered through ointments or even injections. While these medications have to be given for the lifetime of the animal, over time the amount can usually be decreased.

• Shout out to us! Many vets are now recommending that Rex Specs be used in conjunction with medication as a way to keep the condition from worsening over time. See below for more information on dog owners who have used Rex Specs and seen a dramatic impact on the amount of eye drops necessary to keep pannus under control.

• In the most severe cases, your dog may need surgery to decrease/remove the scarring and pigmentation in the cornea that is causing the vision impairment. Again, this will not cure the disease, and the condition will recur if other treatment measures are not continued after surgery.

• There are some cases where a change in diet has reportedly helped slow down the progression of pannus in conjunction with conventional treatment (medication). In all of the cases we’ve read about, treatment includes an anti-inflammatory diet or looking at food allergens as a natural progressor to the disease. We’re not experts, and you’ll probably want to consult your vet about this, but can certainly suggest contacting Karma’s eye specialist: Eye Specialists for Animals, 3515 American Drive, Colorado Springs, CO 80917, Phone: 719-597-9393, Fax: 719-597-6410 Office Hours: Tuesday – Friday, 7 a.m. to 4 p.m.

Karma has been doing just fine since beginning his treatment. He gets drops each day in his eyes and I continue to watch them for any changes. Karma still loves long hikes, so I purchased a set of Rex Specs to add some protection. He became familiar with them very quickly and was wearing them with minimal protest on our last couple of hikes.

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If you suspect any kind of health issue with your dogs eyes or anything else, please get them in to be seen. Let’s try to give our dogs the longest, healthiest, best life they can have. After all, they do so very much for us.