Pannus in Dogs

Pannus, also known as chronic superficial keratitis, is a condition affecting the cornea and third eyelid of a dog’s eye(s). Pannus appears as a grayish-pink film on the eye, and as the disease progresses, the cornea becomes opaque. It most often affects both eyes.

While the exact causes that lead to pannus are not fully understood, there are some factors that can contribute to disease:

  • Exposure to airborne irritants
  • Eyelashes that turn inward (entropion)
  • High altitudes
  • Being exposed to large amounts of direct sunlight
  • Immune-mediated inflammation
  • Underlying eye conditions

German shepherds and Belgian Tervurens have the highest rate of prevalence for pannus, but it may occur in any breed or mix of breeds.


If your pooch develops pannus, you may see the following symptoms:

  • A grayish-pink film on the eye(s)
  • Redness and tearing
  • Cornea pigmentation (dark brown)
  • Opacity of cornea

In order to diagnose your dog’s eye condition, your veterinarian will perform a complete history, physical exam, and eye exam. Additionally, he or she may recommend the following, depending on your dog’s specific needs:

  • A separate visit to a veterinary ophthalmologist, who specializes in eye diseases
  • A Schirmer Tear Test to measure tear production
  • Fluorescent staining of the eye to rule out an ulceration of the eye
  • Cytology (microscopic evaluation of cells) on samples obtained by “scraping” the cornea and/or lining of the eye (coniunctiva).

Blood tests may be recommended to determine the underlying cause. These may include:

  • Chemistry tests to evaluate kidney, liver, and pancreatic disease and function, as well as sugar levels
  • A complete blood count to rule out infection, inflammation, anemia, and other conditions
  • Sceening tests to rule out infectious disease, such as Lyme disease
  • Specialty tests: cultures and PCR testing

Pannus typically requires lifelong treatment, but most cases respond reasonably well with good owner compliance and regular monitoring by a veterinarian. Treatment often includes the use of topical corticosteroids and other eye medications. In extreme cases, surgery or radiation therapy may be used.

Dogs with pannus require ongoing medication to prevent the eye lesions from returning. They also need to receive regular eye exams to identify if any flare-ups occur, once the pannus is under control.

While the cause of pannus can vary, two environmental factors are known to contribute to its taking root:

  • Altitude
  • Exposure to bright sunlight

While you may not be able to move to a lower altitude, you can manage the amount of sunlight your best friend is exposed to, if your veterinarian thinks your pet is at risk.

If you have any questions or concerns, you should always visit or call your veterinarian – they are your best resource to ensure the health and well-being of your pets.