🐾 Vet Guide 2025: Managing Dry Eye (Keratoconjunctivitis Sicca) in Dogs & Cats 👁️

By Dr Duncan Houston, revised 2025

Introduction to Dry Eye (Keratoconjunctivitis Sicca)

Dry Eye, also known as keratoconjunctivitis sicca (KCS), is one of the most common ocular conditions seen in veterinary medicine. Tears are more than tears—they’re a vital cocktail of water, oil, mucus, and antimicrobial proteins that nourish and protect the eye.

When tear production diminishes, the result is a chronically dry, inflamed, and uncomfortable eye that can progress to vision loss if left untreated. 😢

🔬 Why Tears Matter: More Than Just Moisture

• Lubrication & Comfort: Tears keep the cornea smooth and irritation-free.
• Antimicrobial Protection: Contains lysozymes and salts that protect against infection.
• Waste Removal: Helps flush debris and metabolic byproducts from the corneal surface.

Understanding Keratoconjunctivitis Sicca

KCS literally means inflammation of the cornea and conjunctiva due to dryness. When tears are deficient, oil and mucus thicken on the eye, causing redness, gooey discharge, and potential blindness if untreated. 😿🐶

📋 Causes of KCS in Pets

Dry Eye can arise from various causes, some temporary, others chronic:

• Immune‑mediated gland destruction – the most common cause in dogs, where the body attacks its own tear glands.
• Infectious agents: Canine distemper virus, feline herpesvirus.
• Drug-related: Sulfonamides like trimethoprim‑sulfa.
• Trauma: Injury, surgery (especially after cherry eye correction), or nerve damage.
• Congenital: Some breeds (e.g. Yorkshire Terriers) may have underdeveloped tear glands.

Breed Predisposition

• American Cocker Spaniel
• Miniature Schnauzer
• West Highland White Terrier
• Yorkshire Terrier (congenital form)

🩺 Recognizing the Signs

How can you spot Dry Eye?

• Red, inflamed conjunctiva
• Thick, yellow‑white discharge
• Gooey build-up around the eye
• Brown pigmentation on corneal surface
• Possible vision impairment or blinking/squinting

Schirmer Tear Test: Confirming the Diagnosis

The gold standard test involves placing a calibrated paper strip inside the lower eyelid for 60 seconds. Outcome:

• ≥15 mm – normal tear production
• 11–14 mm – borderline
• <10 mm – dry; <5 mm – severely dry

🐱🐶 Standard Treatment Protocols

In 2025, Dry Eye treatment has become far more effective thanks to advanced therapy options:

Optimmune® (0.2% Cyclosporine Eye Ointment)

The frontline therapy for immune‑mediated KCS. It modulates the immune response and allows tear glands to recover, often within 1–4 months. Dosing is 1–3 times daily.

Monitoring: Recheck tear values after one month; adjust dose accordingly. Long-term use is common—some pets require lifelong maintenance.

Tacrolimus (Compounded Eye Drops)

When cyclosporine is insufficient, tacrolimus can be used. It’s equally effective but must be custom‑compounded. It works similarly but may require more frequent dosing.

Pilocarpine (Neurogenic KCS Only)

For dogs with nerve-related tear deficiencies, oral pilocarpine can help stimulate glands. Side effects include drooling, diarrhea, and vomiting—dosing must be tailored carefully.

Artificial Tears & Lubricants

Used adjunctively, especially early in treatment. Depending on severity, these may be needed 2–12 times daily to provide immediate comfort.

Antibiotics & Anti‑Inflammatories

Often used short-term to prevent or treat bacterial conjunctivitis. Eye drops may combine antibiotics with mild steroids.

Surgical Option: Parotid Duct Transposition

In refractory cases, rerouting saliva to the eye can restore moisture. It's effective but may cause mineralization issues. Usually done by an ophthalmologist.

🏥 Treatment Timeline & Follow-up

1. Start cyclosporine/tacrolimus and artificial tears immediately.
2. Recheck in 3–4 weeks: repeat Schirmer test.
3. If tear production remains low, increase frequency or switch meds.
4. Once normal tear production achieved, taper frequency (1x/day maintenance).
5. Periodic rechecks—every 3–6 months, lifelong management.

📉 Prognosis & Long‑Term Outlook

Many pets (even severely dry ones with <5 mm baseline) respond positively to treatment. Life-long care is essential, but vision and comfort can be restored. Quality of life often improves dramatically!

💡 Owner Tips for Success

• Set reminders for medications—daily consistency is key.
• Clean discharge gently with saline or warm water.
• Avoid cotton swabs—use soft gauze instead.
• Monitor for signs of infection or sudden pain.
• Understand the financial and time commitments—be realistic.

Frequently Asked Questions (FAQs)

Can Dry Eye cause blindness?

Untreated KCS can lead to scarring, pigmentation, and loss of sight—but treatment reverses damage and restores function.

Is KCS contagious?

No—this is not contagious. It’s an individual medical condition.

Can treatment be stopped once tear production improves?

Often a maintenance dose is needed lifelong. Some dogs may need meds for years; others maintain after tapering under vet supervision.

Can I use over-the-counter eye drops?

Only veterinarian-recommended lubricants should be used. Human OTC drops may lack necessary preservatives or moisturizing properties.

📚 Latest Research & Innovations (2025)

• High‑strength cyclosporine formulations: Show promise for faster outcomes in severely dry eyes.
• Combined immunomodulator drops: New compounds entering clinical trials.
• Parotid duct long‑term study: 5‑year outcomes show 80% retention of vision, with mineralization to monitor.

When to See a Specialist 🤓

• Poor response to standard therapy after 3–4 months.
• Recurring corneal ulcers or infections.
• Suspected neurogenic KCS—consult for oral pilocarpine therapy.
• Surgical intervention (e.g., parotid duct) is being considered.

📌 Key Takeaways

• Dry Eye is common, painful, and blinding if ignored—but highly treatable in 2025.
• Diagnosis is confirmed via Schirmer Tear Test.
• Cyclosporine ointment (Optimmune®) remains the gold standard.
• Alternative therapies include tacrolimus, pilocarpine, and surgery when needed.
• Adherence to therapy and regular checkups are critical for success.

Conclusion

By recognizing Dry Eye early, pursuing proper veterinary care, and keeping up with treatment, pet owners can be their cat or dog’s hero. With the right approach, KCS becomes a manageable condition, not a life sentence. 🦸‍♀️🐾

— Dr Duncan Houston, DVM