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If Your Cat’s Tears Won’t Stop — Causes of Nasolacrimal Duct Obstruction and When to Seek Treatment

Eye HealthDiseasesMeongsiljang Veterinary Advisory Board

Feline nasolacrimal duct obstruction is a condition in which tears cannot drain properly, causing them to pool or leak onto the surrounding fur. It can be caused by a variety of factors, including infection, trauma, or congenital structural abnormalities.

Feline Nasolacrimal Duct Obstruction Is a Condition Caused by a Blocked Tear Drainage Pathway

A cat with tear staining and wetness around the eyes due to blocked tear ducts

Feline nasolacrimal duct obstruction occurs when the nasolacrimal duct is blocked, preventing tears from draining normally into the nasal cavity or oral cavity. Because a cat’s nasolacrimal duct opens deep within the nasal passage toward the rear, tears often flow into the mouth rather than out through the nostrils. When drainage is obstructed, tears accumulate around the eyes, leaving wet stains, and the risk of infection increases over time. - Nasolacrimal duct obstruction: This condition involves tears failing to pass through the nasolacrimal duct and pooling around the eyes. Causes may include congenital structural abnormalities, infections, inflammation spreading from surrounding tissues, or foreign bodies. - Brachycephalic factors: Brachycephalic breeds with flat faces, such as Persians, have nasolacrimal duct pathways that are more tortuous or narrow, making them structurally prone to chronic epiphora (excessive tearing). - Infection risk: Accumulated tears create an environment conducive to bacterial growth, which can lead to conjunctivitis or dermatitis. Early detection and proper management are essential.

The Main Causes of Nasolacrimal Duct Obstruction Are Structural Abnormalities and Infection

There are many causes of feline nasolacrimal duct obstruction. Brachycephalic breeds like Persians often have a tortuous or narrow nasolacrimal pathway, making tear drainage structurally difficult. Additionally, congenital aplasia or hypoplasia of drainage structures such as the puncta, canaliculi, or nasolacrimal duct typically presents at a young age. - Congenital abnormalities: Part of the nasolacrimal system may be congenitally narrow or blocked, causing symptoms even in young cats. - Infection and inflammation: Bacterial infections or inflammation of surrounding tissues can cause swelling of the nasolacrimal mucosa, which may later lead to scarring and fibrosis, narrowing the passage. - Foreign bodies and tumors: Foreign material or tumors can also obstruct the drainage pathway. Early diagnosis and identifying the underlying cause are key to treatment.

An anatomical diagram illustrating the structure of a cat’s tear ducts and the location of obstructions.

The Main Symptoms Are Frequent Tearing and Dampness Around the Eyes

The most common sign of feline nasolacrimal duct obstruction is persistent tearing. You may notice the area around the eyes is consistently damp, with dark brown tear stains forming, and the fur around the eyes often feels sticky. - Increased tear production: When the nasolacrimal duct is blocked, tears cannot drain properly, causing them to overflow. - Changes around the eyes: The skin around the eyes may become inflamed, leading to swelling, itching, or pain. - Changes in discharge: Sticky discharge may appear, or the eyes may become red. If symptoms persist, the risk of infection increases, so immediate veterinary care is necessary.

A cat with moist eyes and tear stains caused by blocked tear ducts

If Tears Flow Continuously or the Eye Area Swells, Immediate Veterinary Visit Is Necessary

If your pet experiences persistent tearing, swelling around the eyes, or signs of pain, it may indicate a progressing infection or inflammation. Leaving this condition untreated can damage the mucous membranes of the nasolacrimal duct, and post-inflammatory scarring or fibrosis may worsen the blockage. If symptoms persist, it is crucial to seek veterinary care.

Diagnosis Is Performed Using a Tear Flow Test and Endoscopic Examination

Diagnosing feline nasolacrimal duct obstruction begins with a tear flow test using fluorescein dye, known as the Jones test. After applying fluorescein dye to the surface of the eye, if the dye appears from the nose or mouth within a few minutes, it indicates that the nasolacrimal duct is open. In cats, the dye is more commonly observed emerging from the mouth (specifically the tongue) rather than the nostrils. - Nasal endoscopy: When necessary, this procedure allows direct visualization of the nasal cavity and nasolacrimal duct area to determine the location and severity of the obstruction. - Imaging studies: Imaging tests such as CT scans help identify complex structural abnormalities and assist in preoperative evaluation. - Accurate diagnosis: Combining multiple diagnostic methods to clearly identify the underlying cause greatly aids in developing an effective treatment plan. Early diagnosis improves the success rate of treatment.

A veterinarian examining a cat's tear ducts with an endoscope

Treatment Consists of Removing the Obstruction and Managing Infection

Treatment depends on the cause and severity of the obstruction. - Nasolacrimal duct dilation: If the nasolacrimal duct is blocked, surgery is required to dilate it with specialized instruments or reconstruct it through suturing. - Antibiotic therapy: If infection is present, antibiotics are administered to eliminate bacteria and reduce inflammation. - Support for mucosal regeneration: If the mucosa is damaged, medications that promote healing or mucosal protectants are used. - Ongoing care: Regular check-ups and continued medication are necessary even after surgery. The key to treatment is long-term management, not just a short-term fix.

A cat recovering from nasolacrimal duct surgery

The Key to Home Care Is Maintaining Cleanliness and Preventing Infection

The key to managing feline nasolacrimal duct obstruction is keeping the area around the eyes clean. Gently wipe the eye area daily with a soft cloth or sponge, and avoid using alcohol or disinfectants that could cause irritation. - Hair care: If the hair around the inner corner of the eye (medial canthus) is long, tears can easily run down the hair and wet the surrounding area. Consult your veterinarian about trimming this hair to help prevent this issue. - Medication: Follow your veterinarian’s instructions for medication and do not stop administering it without consulting them. - Environmental care: Avoid dusty environments and frequently wipe the eye area to prevent it from staying wet. Consistent care is crucial in preventing recurrence.

A caregiver gently wiping around a cat's eyes

The Risk of Feline Nasolacrimal Duct Obstruction Varies by Breed

Brachycephalic cats with flat faces, such as Persians, are at higher risk for nasolacrimal duct obstruction and chronic excessive tearing (epiphora). Their nasolacrimal ducts are often tortuous or narrow, and anatomical features like ventromedial entropion can cause tears to overflow easily. Early diagnosis and consistent management are essential.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Is it normal for my cat to tear up frequently?

No, persistent tearing can be a sign of a blocked tear duct or an infection. If the symptoms continue, it’s best to have your pet examined by a veterinarian.

How can I remove tear stains?

Keeping the area around your pet's eyes clean is essential. Gently wipe the eye area daily with a soft cloth, and consider trimming the hair around the inner corners of the eyes after consulting with your veterinarian. Specialized products are not necessarily required.

Can a blocked tear duct be cured with surgery?

In most cases, symptoms can be significantly improved by surgically widening or reconstructing the bile duct. However, because recurrence is possible due to scarring or stricture, a complete cure cannot be guaranteed, and outcomes vary depending on the underlying cause and the patient's condition.

What kind of food is good for a cat with tear stains?

Rather than the tear stains themselves, more common causes include blocked nasolacrimal ducts, infections, or structural factors such as those seen in brachycephalic breeds. While you should consult your veterinarian to choose a balanced diet, it’s difficult to claim that any specific food will eliminate tear stains.

Can tear duct obstruction recur?

Yes, even after treatment, the nasolacrimal duct can become narrowed or blocked again due to post-inflammatory scarring or fibrosis. Regular check-ups and proper care around the eyes can help prevent recurrence.

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References

[1] Gelatt KN et al. (2013). Veterinary Ophthalmology, 2nd ed. Wiley-Blackwell, Oxford, UK.

[2] Esson DW and Calvarese S (2022). Clinical Atlas of Canine and Feline Ophthalmic Disease, 2nd ed. John Wiley & Sons, Inc.

[3] Ny Y et al. (2006). Medial canthoplasty for epiphora in dogs: a retrospective study of 23 cases. J Am Anim Hosp Assoc, 42, 435–439.