Vet’s 2025 Guide to Pannus in Dogs Chronic Superficial Keratitis Explained👁️🩺

Vet’s 2025 Guide to Pannus in Dogs: Chronic Superficial Keratitis Explained👁️🩺

By Dr. Duncan Houston BVSc

🐾 What Is Pannus?

Pannus, also known as chronic superficial keratitis (CSK), is a lifelong immune-mediated condition that affects a dog’s eyes—specifically, the cornea (the clear outer surface). This non-infectious disease gradually causes inflammation, blood vessel growth, pigment buildup, and eventually corneal scarring that can impair vision or lead to blindness if left untreated.

🧬 What Causes Pannus in Dogs?

Pannus is caused by the immune system mistakenly attacking the dog’s corneal tissue. While the exact reason isn’t fully known, genetics, environment, and UV light exposure play key roles.

📌 Contributing factors:

Genetics: Inherited tendency, especially in certain breeds.
UV radiation: High exposure to sunlight increases severity.
High altitudes: More UV rays in mountainous areas worsen inflammation.
Air pollution or smoke: May aggravate or trigger symptoms.

🐶 Breeds Most at Risk

Pannus is particularly common in:

German Shepherds 🇩🇪
Belgian Tervurens 🇧🇪
Greyhounds 🐾
Siberian Huskies ❄️
Border Collies 🐕
Australian Shepherds 🇦🇺

👁️ Clinical Signs of Pannus

Symptoms often start subtly but worsen without treatment. They typically affect both eyes, though not always symmetrically.

🕵️ Early signs:

Pink, raised lesion on the outer corner of the eye
Small blood vessels creeping into the clear cornea
Grey or hazy areas over the eye

⚠️ Progressing signs:

Corneal pigmentation (brown or black coloration)
Scarring or vision loss
Discharge, squinting, pawing at the eye
Thickened third eyelid or conjunctival swelling

Note: Pannus is not painful in the early stages but can become irritating if advanced or infected.

🔬 How Is Pannus Diagnosed?

Your veterinarian will usually diagnose pannus with a combination of clinical signs and a detailed eye exam. Additional diagnostics help rule out other conditions:

Ophthalmic exam: To check corneal clarity, blood vessels, pigmentation.
Fluorescein stain: Rules out ulcers.
Schirmer tear test: Ensures tear production is normal.
Intraocular pressure: To rule out glaucoma.

If needed, a referral to a veterinary ophthalmologist can confirm the diagnosis with imaging or cytology.

💊 Treatment Options in 2025

Pannus is not curable—but it is very manageable with lifelong medication and care. The goal is to control inflammation, prevent progression, and preserve vision.