Pannus in Dogs (Chronic Superficial Keratitis): Symptoms, Complication, and Treatment

Pannus in dogs (chronic superficial keratitis) is a chronic, inflammatory, immune-mediated, and potentially vision-threatening cornea disease. Pannus in dogs is known as chronic superficial keratitis (CSK).

CSK occurs alone or in combination with its variation, nictitans plasmacytic conjunctivitis or plasmoma. The condition is prevalent in German Shepherds, Shepherd crosses, and greyhounds.

A faulty immune system, genetic predisposition, and environmental factors cause pannus dogs. Autoimmune eye disease in dogs is rare but serious.

Pannus in dogs causes symptoms such as red eyes, patchy lesions, eye discharge, corneal cloudiness, and an inflamed third eyelid. Early pannus in dogs looks asymmetrical or affects one eye, although both eyes are affected.

The treatment of pannus in dogs’ eyes includes topical steroids and immunosuppressants, a surgery called keratectomy, and radiotherapy. Regular vet checkups and dog goggles are critical for preventing pannus flare-ups.

What is Pannus in Dogs?

Pannus in dogs is a chronic immune-mediated eye disease. Pannus is a progressive and potentially blinding corneal disease marked by chronic inflammation, neovascularization, pigmentation, and opacification, defined in the study “Chronic Superficial Keratitis in Dogs,” published in Medicine in 1975.

Pannus occurs when blood vessels and pigment invade the cornea from the ear side of the eyes and progress toward the nose side of the eyes.

The blood vessels and pigment cause inflammation, which is pink and fleshy and affects both eyes. The inflammation is severe in one eye, causing asymmetrical eye changes. Pannus eventually covers the entire eye, causing blindness because the dog is unable to see through the dark pigment.

Pannus is an uncommon dog eye problem. Dog owners who ask, “What is pannus in dogs?” must know that the condition varies. The pannus variation is called nictitans plasmacytic conjunctivitis (plasmoma) and affects the third eyelid.

What are the other terms for Pannus in Dogs?

The other terms for pannus in dogs are chronic superficial keratitis (CSK), German Shepherd pannus, Überreiter’s syndrome, and degenerative pannus.

The most popular term is chronic superficial keratitis or its abbreviation CSK. Chronic superficial keratitis describes the condition. Chronic means long-term, superficial means it affects the outer layers, and keratitis refers to the cornea.

The term German Shepherd pannus is derived from the prevalence of pannus in German Shepherds (GSDs) and German Shepherd mixes.

How does Pannus in dogs differ from other autoimmune diseases?

Pannus in dogs differs from other autoimmune diseases in triggers, clinical manifestations, and consequences.

Pannus is an immune-mediated condition, meaning immune cells act abnormally and overreact or attack the dog’s body. Pannus is dependent on genetic and environmental factors, primarily UV lights. Pannus cases differ from other autoimmune diseases in terms of signs. Dogs with pannus have inflamed and pigmented corneas.

Pannus is a rare autoimmune disease in dogs eyes compared to other autoimmune conditions, such as keratoconjunctivitis sicca, caused by inadequate tear production or quality leading to dry eyes, and uveodermatologic syndrome, which affects eye pigments and causes inflammation.

How are Pannus in Dogs developed?

Pannus in dogs develops slowly. The condition starts as an elevated and non-painful pink mass on the outside corner of the eye.

Pannus in the right eye and positioned between eight to eleven o’clock. The pannus in the left eye is positioned between one to four o’clock if the eyes are imagined as clock faces.

Pannus spreads from the starting position and travels toward the inner corners of the eyes. The third eyelid is thick, red, and inflamed. The masses flatten over time and become pigmented.

The cornea develops scars, and mucoid discharge is present in the corners of the eyes. The pannus is bilateral (affects both eyes) but asymmetrical (one eye is worse than the other).

Dogs typically develop pannus between four to seven years old, but pannus affects younger and older dogs.

Who is at risk of developing Pannus in Dogs?

Middle-aged to older German Shepherds are at risk of developing pannus in dogs. The disease is immune-mediated with an inheritable component. Prolonged UV light exposure and living at high altitudes increase the risk of developing pannus.

The median age of onset of pannus is between five and eight years of age. Pannus is able to develop in dogs of all ages, from puppies to seniors.

What breeds are more prone to developing Pannus?

The breeds more prone to developing pannus are listed below.

German Shepherds: Chronic superficial keratitis has the highest incidence in German Shepherd (GSD) breed members.
English Greyhounds: Greyhounds are the second most commonly affected breed with chronic superficial keratitis.
Belgian Tervurens: Belgian Tervurens are frequently diagnosed with pannus because of their close relationship with German Shepherds.
Belgian Shepherds: Belgian shepherd breed members have a higher-than-average risk of pannus due to a genetic background similar to GSDs.
GSD Mixes: German Shepherd mixes are highly susceptible to pannus, hence the popular name, pannus German Shepherd.

How common are Pannus in Dogs?

Pannus in dogs is uncommon. Specific statistics about the condition’s incidence are not available. Vets report that around 90% of the pannus cases occur in German Shepherds.

Pannus occurred in 29 dogs in a five-year period (1970 to 1975) according to a study “Chronic Superficial Keratitis in the Dog--II. Results of a Combined Non-Surgical Treatment” published in The Journal of Small Animal Practice in 1978.

The 29 cases suggest that the issue is rare among dogs. Middle-aged and older dogs are more likely to develop pannus.

How is Pannus in Dogs Different from Dog Cataract?

Pannus in dogs is different from dog cataracts in causes and treatment options. Pannus is an immune-mediated condition, while diabetes is the most common cause of cataracts.

Pannus requires a combination of medications and, in severe cases, surgery. Cataracts always require surgical correction.

Pannus is similar to dog cataract because the conditions cause opacity and result in blindness unless treated promptly and correctly.

What does Pannus in Dogs look like?

Pannus in dogs looks like pink and fleshy eye inflammation spreading from the outer to the inner corner of the nose. The inflammatory lesions are raised and then flattened. Scarring and hyperpigmentation occur in the advanced stages. Dogs with pannus and the related immune condition, plasmoma, have red and swollen third eyelids.

What are the Causes of Pannus in Dogs?

The causes of pannus in dogs are listed below.

Faulty Immune System: The leading cause of pannus in dogs is a faulty immune system. The condition occurs when the dog’s immune system triggers an attack against its eye cells.
Genetic Predisposition: Pannus is prevalent in German Shepherds, Belgian Tervurens, Belgian Shepherds, Greyhounds, and GSD mixes, suggesting a genetic factor in the condition’s development.
Environmental Factors: Sun exposure (UV lights), high altitudes, airborne allergens, and underlying eye conditions increase the risk of pannus in dogs and worsen the signs of existing chronic superficial keratitis.

What are the Symptoms of Pannus in Dogs?

The symptoms of pannus in dogs are listed below.

Red Eyes: Redness of the eyes is one of the earliest pannus signs. Redness is a sign of inflammation and is the most striking on the whites of the eyes.
Patchy Lesions: The eye develops white patches (accumulated inflammatory cells), which turn pink (blood vessel invasion) and then dark brown (hyperpigmentation).
Eye Discharge: Dogs with pannus develop mucoid eye discharge, which dries up in contact with the air and forms crusts. The crusts make the dog uncomfortable.
Corneal Cloudiness: Corneal cloudiness or opacity develops in the more advanced pannus stages. The cornea loses its transparency and becomes cloudy or hazy.
Inflamed Third Eyelid: A red and swollen third eyelid is an early sign of German Shepherd pannus combined with plasmoma or nictitans plasmacytic conjunctivitis.

Can pannus in dogs be confused with other eye conditions?

Yes, pannus in dogs can be confused with other eye conditions. Differential diagnoses for pannus include dry eye and corneal ulcers.

Dry eye or keratoconjunctivitis sicca is a dry inflammation caused by inadequate tear production. Corneal ulcers are crater-like defects on the surface of the cornea. Corneal ulcers in some dogs develop as a complication of dry eye.

Differentiating pannus from dry eye and corneal ulcers is essential for prescribing the correct treatment.

When does Pannus in Dogs Symptoms usually occur?

Pannus in dogs symptoms usually occur when dogs are between four and seven years old. The symptoms are triggered or worsen following extended sun exposure and high altitudes.

Pannus is most severe in younger dogs. Younger dogs with pannus are less likely to respond to treatment.

Dogs that develop pannus after age five experience milder symptoms and are more likely to respond positively to therapy.

What are the Risk Factors of Pannus in Dogs?

The risk factors of pannus in dogs are listed below.

UV Lights: Extended exposure to sunlight, more precisely to UV lights, triggers and worsens pannus in predisposed dogs.
High Altitudes: Living at high altitudes and frequent hiking increases the risk of pannus in sensitive dogs.
Airborne Irritants: Exposure to airborne allergens and irritants, such as cigarette smoke or pollen, is believed to increase the risk of pannus.
Eye Issues: Underlying eye and eyelid conditions in some dogs are connected to a high incidence of chronic superficial keratitis.

Can diet influence the risk of pannus in dogs?

No, diet cannot influence the risk of pannus in dogs. Pannus is an immune-mediated eye issue. Diet does not have a direct effect on autoimmune conditions.

Pannus in dogs is affected by other factors, including genetics and environmental factors such as prolonged exposure to sunlight and staying in high-altitude places.

Is pannus in dogs a genetic condition?

Yes, pannus in dogs is a genetic condition. Pannus is an inflammatory, autoimmune disease with a pronounced genetic component.

CSK is prevalent among German Shepherds, Belgian Shepherds, and Belgian Tervurens. GSD mixes are at a higher-than-average risk, too.

Other high-risk breeds are Greyhounds, Rottweilers, Rhodesian Ridgebacks, Border Collies, Australian Shepherds, and Siberian Huskies.

What are the complications of Pannus in dogs?

The complications of pannus in dogs are listed below.

Plasmoma: Plasmoma or plasmacytic lymphocytic conjunctivitis is a pannus variation that, in some dogs, coexists with the CSK and complicates the clinical picture.
Scar Tissue: Pannus in dogs results in intense scar tissue. Excess scars on the cornea block the dog’s vision, causing deficits.
Blindness: Partial vision deficit or complete blindness is the culmination of pannus. Vision problems occur in severe and advanced cases that are not treated promptly.

How is Pannus in Dogs Diagnosed?

Pannus in dogs is diagnosed based on breed predisposition, clinical manifestation, and examination results. The veterinarian starts with a physical examination and the dog’s history, then focuses on testing the eyes.

The three main eye tests are the Schirmer tear test (STT), fluorescein eye stain test, and intraocular pressure test.

The Schirmer tear test (STT) checks the tear production and helps rule out dry eyes. The stain test detects corneal ulcers. The intraocular pressure (IOP) is measured to check for glaucoma.

Where can you seek a diagnosis for Pannus in dogs?

You can seek a diagnosis for pannus in dogs at the general vet or a veterinary ophthalmologist. The general veterinary practitioner sometimes refers patients to specialists for a diagnosis and individually tailored treatment plan.

Veterinarians are unable to diagnose pannus in dogs based on a single test. Making a definitive diagnosis requires eliminating other diseases. The dog’s breed and the high pannus incidence in certain dogs help the veterinarian.

How long can a dog survive with Pannus?

Dogs with pannus can survive for a long time. Pannus is not a life-threatening condition. Left untreated, however, pannus affects vision and lowers the dog’s quality of life.

Dogs with pannus require lifelong treatment. Regular medication administration and check-ups are necessary to ensure the dog does not relapse.

What are the treatment options for pannus in dogs?

The treatment options for pannus in dogs are listed below.

Topical Therapy: Topical therapy combines Corticosteroids with immunosuppressants such as cyclosporine and tacrolimus. The medications are available as drops or ointments and are applied several times daily. Topical therapy is used to stop the disease from progressing.
Subconjunctival Injections: Dogs with severe CSK benefit from steroid injections given directly into the eye. The injection boosts the efficacy of the topical therapy.
Surgery: A surgical procedure called superficial keratectomy is performed in dogs that fail to respond to medical therapy. The method entails peeling off the cornea's outer layer, thus removing the scars and patchy lesions that block vision.
Radiotherapy: “Soft X-ray irradiation combined with keratectomy is a safe and effective new treatment option for severe and advanced CSK,” says a study “Radiotherapy for canine chronic superficial keratitis using soft X-rays (15 kV)” published in Veterinary Ophthalmology in 2010.
Protective Goggles: Dogs with pannus triggered or exacerbated by UV lights must wear protective goggles when outside. Goggles for canines are surprisingly effective and well-accepted.
Periodic Eye Exams: Periodic eye examinations are recommended to maintain pannus in check and prevent flare-ups. Veterinarians recommend three or four checkups per year as part of the pannus in dogs treatment.

How can boosting a dog's immune system help with pannus?

Boosting a dog’s immune system cannot help with pannus. Pannus is an autoimmune condition. Autoimmune disease is caused by an overactive immune system that acts abnormally by attacking the body or failing to respond to threats.

Strong immunity is counterproductive, increasing the risk of an immune system overreaction. Boosting a dog’s immune system does not suppress or alleviate pannus symptoms.

Immune support, though medication and natural supplements such as CBD oil for dogs, help enhance the dog’s health, but it does not help manage pannus.

Can CBD Oil be an option for treating pannus in dogs?

Yes, CBD oil can be an option for treating pannus in dogs. CBD alone is not enough to treat or manage pannus, but when used properly, it is beneficial.

CBD modulates the immune system as a main pannus trigger and reduces inflammation as a primary pannus symptom.

CBD or cannabidiol is extracted from the hemp plant. CBD oil for dogs is non-addictive and fit for dogs of all ages.

What is the recovery time after treatment for a Pannus in Dogs?

The recovery time after treatment for pannus in dogs is variable because pannus is a lifelong condition that requires ongoing care.

The lesions that impair the dog’s vision typically resolve within a few weeks. Surgical scar tissue removal is recommended for dogs with significant vision deficits. The recovery time after surgical treatment is one month.