Blocked Tear Ducts (Nasolacrimal Obstruction) in Donkeys

Quick Answer
  • Blocked tear ducts in donkeys usually cause one-sided watery eye, tear overflow, crusting, and damp hair below the inner corner of the eye.
  • Common triggers include debris, inflammation, infection, facial trauma, scarring, and pressure on the duct from nearby swelling or dental disease.
  • Your vet may confirm the problem with an eye exam, fluorescein stain, and a nasolacrimal flush through the nostril opening.
  • Many cases improve after flushing and treating the underlying irritation, but chronic or structural blockages can recur.
  • See your vet promptly if the eye is painful, cloudy, swollen, held shut, or producing thick yellow-green discharge.
Estimated cost: $150–$1,500

What Is Blocked Tear Ducts (Nasolacrimal Obstruction) in Donkeys?

Blocked tear ducts, also called nasolacrimal obstruction, happen when tears cannot drain normally from the eye into the nose. In donkeys, the tear drainage system works much like it does in horses. Tears should move from small openings near the eyelids into the nasolacrimal duct and then empty inside the nostril. When that pathway narrows or plugs, tears spill over the eyelid instead.

Pet parents often notice this as a constantly wet eye, tear tracks down the face, or crusting at the inner corner of the eye. The medical term for this overflow is epiphora. A blocked duct may be the main problem, but it can also happen along with conjunctivitis, facial swelling, dental disease, or other eye irritation.

Some donkeys are mildly affected and mainly have cosmetic staining or damp hair. Others develop skin irritation, secondary infection, or repeated discharge because the area stays wet. Since painful eye diseases can look similar at first, it is important to have your vet examine any persistent tearing rather than assuming it is only a blocked duct.

Symptoms of Blocked Tear Ducts (Nasolacrimal Obstruction) in Donkeys

  • One eye watering more than the other
  • Wet hair or tear tracks below the inner corner of the eye
  • Clear to mucoid discharge that keeps coming back
  • Crusting or matting of hair around the eye
  • Mild redness of the conjunctiva
  • Skin irritation or hair loss where tears run down the face
  • Thick yellow-green discharge, swelling, or obvious discomfort
  • Squinting, cloudiness, or holding the eye shut

A blocked tear duct often causes chronic tearing without severe pain, but not every watery eye is a simple drainage problem. Squinting, a cloudy eye, marked redness, swelling, or thick pus-like discharge can point to a corneal ulcer, deeper infection, trauma, or another urgent eye condition.

See your vet promptly for ongoing tearing that lasts more than a day or two, and see your vet immediately if your donkey seems painful, keeps the eye closed, or the eye looks blue, white, or injured.

What Causes Blocked Tear Ducts (Nasolacrimal Obstruction) in Donkeys?

In donkeys, blocked tear ducts can be acquired or less commonly congenital. Acquired obstruction is more common and may happen when inflammatory debris, dried discharge, plant material, dust, or other foreign matter plugs the duct. Swelling from conjunctivitis or nearby nasal inflammation can also narrow the drainage pathway.

Trauma to the face is another possible cause. A kick, halter injury, rubbing, or facial wound can lead to swelling or later scarring that interferes with tear drainage. In some equids, masses or sinus disease can press on the duct from the outside. Dental disease is also important to consider because tooth root problems and nearby infection can affect structures around the tear drainage system.

Congenital problems are less common but can include abnormal openings or poor duct development. Your vet will also want to rule out look-alike causes of tearing, such as corneal ulcers, eyelid problems, foreign bodies in the eye, uveitis, and environmental irritation from dust, flies, or wind.

How Is Blocked Tear Ducts (Nasolacrimal Obstruction) in Donkeys Diagnosed?

Diagnosis starts with a full eye exam because excessive tearing can be caused by pain as well as poor drainage. Your vet will look for redness, eyelid abnormalities, corneal injury, foreign material, and the character of the discharge. A fluorescein stain may be used to check for corneal ulcers and, in some cases, to help assess whether tears are passing through the duct normally.

If a blocked duct is suspected, your vet may perform a nasolacrimal flush. In equids, a small tube is typically placed into the duct opening inside the nostril, and sterile fluid is gently pushed through. This can confirm an obstruction and may also clear soft debris at the same time. Some donkeys need sedation because the procedure can be uncomfortable or they may not tolerate restraint well.

If the problem keeps returning or your vet suspects a deeper cause, additional testing may be recommended. This can include oral and dental examination, skull radiographs, contrast imaging of the duct, or referral for advanced imaging. Those steps help identify scarring, masses, sinus disease, or tooth root disease that a simple flush will not fix.

Treatment Options for Blocked Tear Ducts (Nasolacrimal Obstruction) in Donkeys

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$150–$350
Best for: Mild, first-time tearing in a stable donkey without severe pain, cloudiness, or facial swelling
  • Farm-call or clinic exam
  • Basic eye exam to rule out obvious emergency problems
  • Gentle cleaning of discharge and tear scalded skin
  • Nasolacrimal flush if the blockage appears simple
  • Short course of targeted medication only if your vet finds infection or inflammation
Expected outcome: Often good if the blockage is caused by soft debris or mild inflammation and clears with flushing.
Consider: Lower upfront cost, but recurrence is possible if the underlying cause is not identified or if imaging and dental work are deferred.
Most Common

Recommended Standard Treatment

$350–$800
Best for: Most donkeys with persistent tearing, recurrent discharge, or mild conjunctivitis where a practical first-line plan is needed
  • Complete eye exam by your vet
  • Fluorescein stain and tear drainage assessment
  • Sedation if needed for safe handling
  • Nasolacrimal flush and repeat flush if indicated
  • Topical or systemic medications based on exam findings
  • Recheck visit to confirm drainage and comfort
Expected outcome: Good in many uncomplicated cases, especially when the duct can be reopened and the source of irritation is treated.
Consider: More complete than conservative care, but still may not solve structural, dental, or mass-related obstruction without further workup.

Advanced / Critical Care

$800–$1,500
Best for: Chronic, recurrent, painful, or one-sided cases with facial swelling, suspected dental disease, trauma, or poor response to flushing
  • Referral-level ophthalmic or equine exam
  • Dental evaluation and oral exam if tooth root disease is suspected
  • Skull radiographs, contrast studies, or advanced imaging
  • Culture or additional diagnostics for chronic infection
  • Specialized procedures for recurrent, scarred, or complex obstruction
  • Hospital-based monitoring and follow-up care
Expected outcome: Variable but often fair to good when the underlying cause can be identified and addressed; guarded if there is severe scarring or a space-occupying lesion.
Consider: Highest cost range and more travel or sedation may be needed, but this tier can uncover problems that basic treatment misses.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Blocked Tear Ducts (Nasolacrimal Obstruction) in Donkeys

Bring these questions to your vet appointment to get the most out of your visit.

  1. Does this look like a simple blocked duct, or could there be a painful eye problem causing the tearing?
  2. Do you recommend a fluorescein stain or other eye tests before flushing the duct?
  3. Would my donkey benefit from sedation for a safer and more complete exam?
  4. Is there any sign of conjunctivitis, corneal ulcer, trauma, or uveitis along with the tearing?
  5. Could dental disease, sinus disease, or facial swelling be contributing to the blockage?
  6. If you flush the duct today, what signs would mean it is blocked again?
  7. What home care is safe around the eye, and what products should I avoid using unless you recommend them?
  8. At what point would you suggest imaging, dental workup, or referral?

How to Prevent Blocked Tear Ducts (Nasolacrimal Obstruction) in Donkeys

Not every case can be prevented, especially if a donkey has unusual anatomy or develops scarring after injury. Still, good daily management can lower the risk of irritation and secondary blockage. Keep bedding and hay as dust-controlled as practical, reduce exposure to blowing debris, and use fly control to limit rubbing and eye irritation.

Check your donkey's eyes regularly, especially during dusty weather, fly season, or after transport and turnout changes. Early attention to mild tearing, conjunctivitis, or facial wounds may prevent ongoing inflammation from narrowing the duct. If discharge is present, gently wipe it away with clean material and ask your vet before using any eye products.

Routine dental care also matters. Because tooth root disease and nearby facial structures can affect the tear drainage system in equids, regular oral exams are part of prevention for recurrent one-sided eye discharge. If your donkey has repeated tearing from the same eye, ask your vet whether a deeper dental or sinus workup makes sense.

Find a Vet Near You