Health & Diseases

Keratitis in Dogs: Corneal Inflammation, Pannus & Ulcer

Keratitis is an inflammation of the cornea of the eye. The cornea is the transparent outer layer of the eye – any clouding, ulceration, or vascularization is a pathological sign. Keratitis can occur unilaterally or bilaterally and has various causes: infectious, immune-mediated, traumatic, or due to drying.

Keratitis in dogs: corneal inflammation, pannus & ulcer

What is keratitis in dogs?

Keratitis is inflammation of the cornea of the eye. The cornea is the transparent outer layer of the eye — any opacity, ulceration, or vascularization is a pathological sign. Keratitis can occur in one eye or both eyes and has different causes: infectious, immune-mediated, traumatic, or drying-related.

Clinically, keratitis presents with: eye discharge, blinking and squinting of the eye (blepharospasm), corneal opacity, reddish tissue on the cornea (vascularization/pigmentation), light sensitivity. In cases of ulceration, keratitis is acutely painful.

Background + scientific classification

Gelatt (2013, Veterinary Ophthalmology, 5th ed.) classifies forms of keratitis: Ulcerative keratitis (corneal ulcer): loss of the corneal epithelium — from superficial (epithelial ulcer) to stromal (deep ulcer) through to descemetocele (only Descemet’s membrane remains intact). Fluorescein staining shows epithelial defects in green. Immune-mediated keratitis (pannus / chronic superficial keratitis, CSK): progressive vascularization and pigmentation of the cornea caused by immune-mediated inflammation. Particularly in German Shepherds. Pigmentary keratitis: melanin deposition in the cornea, often as a result of chronic irritation (e.g., in brachycephalic dogs with trichiasis or incomplete eyelid closure).

Williams (1999, Veterinary Record, https://pubmed.ncbi.nlm.nih.gov/10576564/) describes pannus (CSK) in the German Shepherd: pannus is an immune-mediated, progressive keratitis with superficial vascular ingrowth and pigmentation, preferentially affecting the temporal-inferior cornea. A genetic predisposition in German Shepherds and Belgian Malinois is clearly documented — HLA/DLA-associated. UV radiation is the strongest exogenous intensifier: dogs at high altitudes or with substantial sunlight exposure show more severe courses. Without treatment, progressive blindness due to corneal pigmentation is possible.

Balicki (2012, Polish Journal of Veterinary Sciences, https://pubmed.ncbi.nlm.nih.gov/23390775/) evaluated tacrolimus (FK506) and DMSO in the treatment of CSK in dogs: tacrolimus 0.02% eye drops showed a significant reduction in vascularization and pigmentation in dogs with pannus over 6 months. Cyclosporine A 0.2% is an alternative first-line immunosuppressant for CSK. Both substances act as calcineurin inhibitors — reducing the T-cell-mediated immune response in the cornea. Lifelong therapy is usually required; UV-protective goggles are useful for dogs with pannus.

Vitomalia position

Keratitis is an ophthalmological emergency when ulceration is present — corneal rupture (perforation) can develop within 24–48 hours. Pannus, by contrast, is chronic and predictably manageable if treated early. No “just put in some eye drops” mindset: any eye discharge with corneal involvement needs a veterinary examination.

When does keratitis become relevant?

  • Ocular mucus, tearing, or purulent eye discharge
  • Blinking, squinting, sensitivity to light — painful eye
  • Visible opacity or gray-white change in the cornea
  • Reddish tissue on the corneal surface (vascularization)
  • Predisposed breeds: German Shepherd (pannus), brachycephalic breeds (pigmentary keratitis)

Practical use

Keratitis forms at a glance:

Form Cause Main symptoms Treatment
Superficial ulcer Trauma, infection, foreign body Fluorescein+, pain Antibiotic eye drops, atropine
Deep ulcer/descemetocele Progression, uncontrolled Severe pain, risk of perforation Emergency surgery
Pannus (CSK) Immune-mediated Vascularization, pigmentation Cyclosporine/tacrolimus, UV protection
Pigmentary keratitis Chronic irritation (brachycephalic dogs) Black pigmentation Treatment of the underlying cause (trichiasis surgery)
KCS-associated keratitis Dry eye Mucous discharge, corneal opacity Cyclosporine, artificial tears

First measures if a corneal ulcer is suspected: - No corticosteroids without a diagnosis — cortisone is contraindicated in active ulcers (slows healing, risk of perforation) - E-collar immediately: no scratching, no rubbing - Veterinarian within 24 hours — immediately if there is visible opacity or severe blepharospasm

UV protection for pannus: - Doggles (dog goggles with UV filter): reduce UV exposure and pannus progression - Dogs at high altitudes or with a lot of outdoor exposure benefit especially - Do not replace topical therapy, but use it as a helpful supplement

Common mistakes & myths

  • “A little cloudy cornea will clear up on its own.” Corneal opacity can be an ulcer (emergency), pannus (chronic), or KCS (dry eye) — none of these resolves spontaneously. Early diagnosis prevents blindness.
  • “Cortisone eye drops help with eye redness.” Corticosteroids are absolutely contraindicated in ulcerative keratitis — they inhibit epithelialization, promote collagenolytic activity, and risk corneal perforation. They may only be used after a negative fluorescein test.
  • “Dogs with pannus do not need ongoing treatment.” Pannus cannot be cured — it can be controlled. Without continuous topical therapy (cyclosporine or tacrolimus), pigmentation progresses and leads to blindness.

Scientific status 2026

Keratitis in dogs is well characterized in ophthalmology. Pannus therapy with calcineurin-inhibiting drops (cyclosporine, tacrolimus) is the international standard. Current research is investigating genetic markers for CSK predisposition and the long-term effects of new immunosuppressive formulations. UV-protective goggles have been shown in clinical studies to slow the progression of pannus.

Frequently asked questions

How can I recognize keratitis in dogs?

Typical signs: blinking and squinting, eye discharge, corneal clouding, or reddish tissue on the corneal surface. If there are signs of pain and clouding, see a veterinarian immediately — corneal ulcers can worsen within hours.

What is pannus in German Shepherd dogs?

Pannus (chronic superficial keratitis, CSK) is an immune-mediated inflammation of the cornea with progressive vascularization and pigmentation of the cornea. German Shepherd dogs have a genetic predisposition. Treatment: lifelong cyclosporine or tacrolimus eye drops plus UV protection.

Can I give my dog cortisone eye drops?

Only after veterinary diagnosis and a negative fluorescein corneal test. In cases of corneal ulcer, corticosteroids are contraindicated — they can cause corneal perforation. Self-medication is dangerous.

Related terms

Sources & further reading

  1. Gelatt, K. N. (Ed.) (2013). Veterinary Ophthalmology (5th ed.). Wiley-Blackwell. ISBN 9780470960875.

  2. Williams, D. L. (1999). Chronic superficial keratitis in German Shepherd dogs in the United Kingdom. Veterinary Record, 145(17), 498–501. https://pubmed.ncbi.nlm.nih.gov/10576564/

  3. Balicki, I. (2012). Clinical study on the application of tacrolimus and DMSO in the treatment of chronic superficial keratitis in dogs. Polish Journal of Veterinary Sciences, 15(4), 667–676. https://pubmed.ncbi.nlm.nih.gov/23390775/

Wissenschaftliche Einordnung

Gelatt (2013, Veterinary Ophthalmology, 5th ed.) classifies forms of keratitis: Ulcerative Keratitis (Corneal Ulcer): Loss of corneal epithelium — from superficial (epithelial ulcer) to stromal (deep ulcer) to descemetocele (only Descemet's membrane intact). Fluorescein staining shows epithelial defects as green. Immune-mediated Keratitis (Pannus / Chronic Superficial Keratitis, CSK): progressive vascularization and pigmentation of the cornea due to immune-mediated inflammation. Particularly in German Shepherds. Pigmentary Keratitis: Melanin deposition in the cornea, often as a result of chronic irritation (e.g., in brachycephalic breeds with trichiasis or incomplete eyelid closure).

Williams (1999, Veterinary Record, https://pubmed.ncbi.nlm.nih.gov/10576564/) describes pannus (CSK) in German Shepherds: Pannus is an immune-mediated, progressive keratitis with superficial vascularization and pigmentation, preferring the temporal-inferior cornea. Genetic predisposition in German Shepherds and Belgian Malinois is clearly documented — HLA/DLA-associated. UV radiation is the strongest exogenous enhancer: dogs at high altitudes or with high sun exposure show more severe courses. Without therapy, progressive blindness due to corneal pigmentation is possible.

Balicki (2012, Polish Journal of Veterinary Sciences, https://pubmed.ncbi.nlm.nih.gov/23390775/) evaluated tacrolimus (FK506) and DMSO in the treatment of CSK in dogs: Tacrolimus 0.02% eye drops showed significant reduction in vascularization and pigmentation in pannus dogs over 6 months. Cyclosporine A 0.2% is an alternative first-line immunosuppressant for CSK. Both substances are calcineurin inhibitors — they reduce T-cell-mediated immune response in the cornea. Lifelong therapy is usually required; UV protection goggles are useful for pannus dogs.