Pannus, or Chronic Superficial Keratitis is an immune mediated disease of the eyes with which Ray and Porcia were afflicted. It can cause blindness if not effectively treated. Pannus is not as common a disease in Greyhounds as it is in some other breeds. We are not experts in veterinary medicine, but we maintain this page in hopes of offering some of our practical experience with the disease to people who live with Pannus dogs and offering some resources to deal with it.

If you take away one piece of knowledge from this page it should be that Pannus requires specialized treatment. The disease can easily be controlled in most cases, but even the best general veterinarians simply do not have enough experience with Pannus to treat it effectively. Regular visits to a veterinary ophthalmologist MUST be made to assure that a Pannus dog is receiving the proper levels of the appropriate medications. Long-term application of corticosteroids in the eyes can cause corneal dystrophy. Therefore it is essential that a Pannus dog receive a high enough dose of these medications to effectively control the disease while not going overboard and adding corneal dystrophy as an issue.

Ray languished in GPA Orlando's rescue kennel for several months before we adopted him. We believe that he was not adopted sooner because of his Pannus. When we adopted Ray, the disease was very active in both eyes and he was in peril of losing his sight. Luckily, in time his condition came under control and his eyesight was saved.

We would very much like to hear from others living with Pannus dogs, particularly Greyhounds. Please feel free to write us at greyhounds@retiredgreyhound.tv so we can compare notes on treatment and the effects of the disease.

Here is what is known:

The following is reprinted with permission of The Animal Eye Clinic, Seattle, WA.

Introduction

Pannus, or Chronic Superficial Keratitis, is a slowly progressive disorder of the canine cornea, characterized by pigmentation, vascularization and opacification. The disorder is seen predominantly in the German Shepherd Dog, but sporadic cases occur in other breeds and mixed breeds as well.

Cause

The cause is not known, but several factors are probably involved:

• The breed incidence suggests a heritable predisposition.

• Ultraviolet radiation plays an important role as an inciting and propagating factor. In keeping wit this, dogs living at high altitudes and low latitudes often are more severely affected.

• Immunological factors are believed to contribute. This may be an allergic type of reaction against extraneous materials or against the corneal substance itself.

• Many infectious agents have been incriminated, but probably none plays any significant role.

Signs

The first evidence of this disorder is usually infiltration into the clear cornea, causing white, pink or brown opacification. This invariably starts at the edge of the clear cornea and extends inward. The most common location is at the outer, lower corner of the eye.

Initially, redness and brown pigment may be seen in the mucous membrane just outside the edge of the cornea. Whitish infiltrates of inflammatory cells into the cornea ensue, followed by ingrowth of new blood vessels into the normally avascular cornea. Later, connective tissue grows in, and finally the tissue is pigmented brown.

In a small number of cases, two other symptoms may occur, simultaneously or one at a time. These are thickening, redness and depigmentation of the third eyelid (atypical Pannus) and chronic, erosive ulcers of the lower eyelid near the inner corner of the eye.

When acute or progressing, the disorder may be uncomfortable to the dog. When kept under adequate treatment, the disorder normally does not cause irritation.

Diagnosis

The clinical signs usually are typical enough for a diagnosis to be made, especially when seen in a German Shepherd Dog.

Treatment

Despite intensive research efforts, no permanent cure exists. However, in the vast majority of cases, progress of the disorder can be halted and the problem kept stable, especially if therapy is instituted early. The two initially occurring components, the inflammatory cell infiltrations and the vessel invasion, usually are reversible with therapy, whereas the final connective tissue and pigment depositions often are irreversible once they have occurred.

There are three categories of treatment:

1. Corticosteroid treatment, administered by  intermittent injections under the mucous membrane of the eye, and/or continuous application of eye drops. This is the main line of defense against progression of the disorder and most often suffices. However, treatment must be kept up consistently for the rest of the dog's life. Even short periods of interrupted treatment, for example 2 to 4 weeks, may cause severe recurrence with devastating effects on the dog's vision.

2. A recent addition to our choices of treatment for Pannus is topical 2% Cyclosporine. This drug suppresses the immune response in a manner unlike that of corticosteroids, and, in conjunction with corticosteroid usage, can aid in control of both typical (i.e. corneal) and atypical (i.e. third eyelid) Pannus.

3. Beta-irradiation may be used when medication alone proves insufficient, but it is seldom available in most cities.

4. Excision of a superficial layer from the affected area may restore vision in opacified eyes. This is called keratectomy. However, the recurrence rate postoperatively is high and this method remains only as a last resort.

The main side-effect of prolonged typical corticosteroid treatment is an adverse effect on corneal wound healing. Microscopic wounds of the superficial layer of the cornea occur very commonly and heal rapidly in a normal eye. Under the influence of continuing corticosteroid treatment, minor wounds may progress and can even cause rupture of the eye. The hallmark of such a wound is pain. Therefore, should a dog in corticosteroid treatment show signs of pain (i.e. holding the eye shut or pawing at the eye), it is imperative that the medication be discontinued and a veterinarian consulted.

It is strongly recommended that reexaminations be closely followed. Initially these examinations may need to be bimonthly, and if medical control is obtained then these may be stretched to semiannually. It is imperative that owners contact their veterinarian at any time between scheduled examinations if the appearance of the eye changes.

Other Internet Resources for Pannus Information

• Animal Eye Care LLC: Chronic Superficial Keratitis in dogs.

• WellVet.com: Includes a photo of a Pannus affected eye and holistic treatments.

• Working Dogs.com: This article by Dr. W. Neumann includes a link to an image of a Pannus affected eye.

• Pannus Article: An article by Michael Zigler DVM, Cert. V. Ophthal.

• Pannus Article: From Veterinary Vision in San Mateo, CA.

• Corneal Dystrophy Article: An important issue for Pannus dogs. Corneal dystrophy can be a side effect of long-term application of corticosteroids to the eyes.

• Doggles: Protective and stylish eyewear for the fashion conscious dog.