Dear Daisy Dog
I was shocked when a black coating spread across my German shepherd’s eyes. My vet diagnosed pannus and said that Max would need eye medication for life. Can you tell me more about pannus?
Pannus, also called chronic superficial keratitis (CSK), is inflammation (-itis) of the cornea (kerat-), the normally clear covering of the eye.
The disease occurs most frequently in young to middle-aged German shepherds, but it is also seen in greyhounds and a few other breeds.
The precise cause is unknown, but veterinarians believe that CSK is an auto-immune disease in which the dog’s immune system attacks his own corneas.
In CSK, blood vessels invade both corneas, which often become pigmented by dark melanin deposits, as you observed with Max.
Eventually, the blood vessels and pigmentation cover the entire cornea and cause blindness. Fortunately, it isn’t painful, according to a dog friend of mine with the disease.
While CSK is not curable, lifelong treatment helps control the disease and prevent blindness.
The key is to inhibit the immune system’s attack on the corneas by applying eyedrops or ointments that contain steroids and sometimes cyclosporin.
Excessive ultraviolet light can aggravate CSK, so keep Max out of the sun and buy him eye goggles if you live at or visit high elevations.