CONDITION

Keratoconjunctivitis Sicca (Dry Eye)

Why this matters now

Keratoconjunctivitis sicca tends to develop gradually in middle-aged to older dogs, often between 4 and 10 years of age. Certain breeds, including West Highland White Terriers, Cocker Spaniels, Cavalier King Charles Spaniels, and English Bulldogs, appear to have a higher predisposition. Owners may initially dismiss early signs as minor eye irritation, but the condition often progresses if underlying factors are not addressed.

Without adequate tear production, the surface of the eye can become chronically inflamed and may develop secondary complications. Early on, the eye might appear slightly dull or have a thick discharge. Over time, pigmentation and blood vessel growth across the cornea can occur, potentially affecting vision. The condition tends to be lifelong in most cases, though many dogs respond well to ongoing management.

Signals & patterns

Early signals

Thick, mucoid eye discharge

A sticky, stringy discharge that accumulates around the eye, often more noticeable than normal tear residue.

Eye redness or irritation

The white of the eye and conjunctiva may appear pink or inflamed, suggesting ongoing surface irritation.

Frequent blinking or squinting

Dogs may blink more often or hold the eye partially closed, indicating discomfort from the dry ocular surface.

Dull or lacklustre eye surface

The cornea may lose its normal shine and appear slightly hazy or less reflective than usual.

Later signals

Corneal pigmentation

Brown or black pigment may spread across the surface of the eye as a chronic protective response.

Visible blood vessels on cornea

New blood vessels may grow across the normally clear cornea, a process called neovascularisation.

Corneal ulceration

The dry, vulnerable corneal surface may develop ulcers, which can be painful and vision-threatening.

Click to read about the biological mechanisms

How this is usually investigated

Diagnosing keratoconjunctivitis sicca typically involves assessing tear production alongside examination of the eye surface. A thorough ophthalmic examination helps identify secondary changes that may have developed.

Schirmer tear test

Purpose: Measures tear production by placing a small paper strip in the lower eyelid and timing how far tears travel along it.
Considerations: This is the standard test for diagnosing KCS. Low readings suggest inadequate tear production, though results can vary slightly between tests.

Fluorescein staining

Purpose: Uses a harmless dye to highlight damage to the corneal surface, including ulcers or erosions.
Considerations: Helps identify complications from chronic dryness that may require additional treatment.

Slit lamp examination

Purpose: Provides magnified views of the cornea and anterior eye structures to assess pigmentation, vessels, or scarring.
Considerations: Useful for monitoring disease progression and response to treatment over time.

Tonometry

Purpose: Measures pressure inside the eye to rule out concurrent conditions like glaucoma.
Considerations: May be performed if other eye abnormalities are suspected.

Options & trade-offs

Management of keratoconjunctivitis sicca typically focuses on stimulating natural tear production, supplementing moisture, and controlling inflammation. The approach may be adjusted based on response and the presence of any secondary complications.

Immunomodulatory eye drops

Medications such as ciclosporin or tacrolimus can help restore tear production by reducing immune-mediated destruction of tear glands.

Trade-offs: Often considered a first-line approach. May take several weeks to show full effect. Lifelong treatment is typically needed. Some dogs may develop local irritation initially.

Artificial tear supplements

Lubricating drops or gels provide moisture to protect the ocular surface between natural tear production.

Trade-offs: May require frequent application throughout the day. Can be used alongside other treatments. Some formulations last longer than others.

Anti-inflammatory medications

Topical anti-inflammatory drugs may help reduce corneal inflammation and associated discomfort.

Trade-offs: Usually used short-term or intermittently. Long-term steroid use carries risks if corneal ulcers are present.

Surgical options

In cases that do not respond adequately to medical management, procedures like parotid duct transposition can redirect saliva to moisten the eye.

Trade-offs: Reserved for refractory cases. Can be effective but requires surgical expertise and may have complications including mineral deposits on the eye.

Common misconceptions

Misconception:

"Dry eye will resolve once the discharge clears up"

Reality:

The underlying deficiency in tear production typically persists even when symptoms appear improved. Ongoing management is usually necessary to maintain eye health.

Misconception:

"Eye discharge means there is an infection"

Reality:

The thick discharge in KCS results from mucus overproduction due to inadequate tears, not necessarily infection. However, secondary bacterial involvement can occur.

Misconception:

"This condition only affects older dogs"

Reality:

While more common in middle-aged dogs, KCS can develop at various ages, particularly in predisposed breeds. Younger dogs are not immune.

Observing how the eyes appear throughout the day, noting any changes in discharge, redness, or comfort, can provide useful information. Keeping track of medication schedules and any apparent responses may help guide discussions about management. Understanding that this condition often requires long-term attention can help with planning and expectations.

Last reviewed: Invalid Date · ConciergeVet Clinical Team