Watery eyes in horses: what does it mean?

Why do horses' eyes water in the first place?

Tearing is normal: it keeps the eye surface moist and flushes away minor irritations. Excess tear fluid drains through the tear ducts into the nose. If there is a problem there — due to a blockage, swelling or a structural issue — the fluid runs down the cheek. You can see this from wet, sometimes matted hairs beneath the eye, sometimes with a brownish residue. With a single wet eye and no other symptoms, it may be a temporary irritation. If both eyes are affected at the same time, or if you notice discharge, crusting or redness, something more is going on.

Common causes at a glance

• Dust, seeds or insects under the eyelid — the most common cause in summer
• Conjunctivitis (inflammation of the conjunctiva) caused by bacteria, viruses or allergens
• Blockage or inflammation of the nasolacrimal duct (tear duct)
• Uveitis (moon blindness): a recurring inflammation deeper in the eye
• Trauma or wound to the eyelid or cornea, often caused by branches or fencing
• Fly irritation or allergic reaction to pollen in spring

When is tearing an emergency?

Call the vet immediately if, alongside tearing, you also notice one or more of the following signs:

• The eye is half closed or the muscles around the eye are twitching
• The cornea is cloudy or has a blue or white haze
• There is visible discharge or pus from the eye
• The eye is swollen or the eyeball appears smaller than normal
• Your horse is sensitive to light or actively avoids daylight

What can you check yourself?

Stand in front of your horse in good light and examine both eyes. Look for symmetry: are they the same size, equally clear, equally open? Gently feel along the upper edge of the eyelid for visible swelling. Also check the tear point in the inner corner of the eye — a small pink nodular structure. If it is red or swollen, there may be a tear duct inflammation. Rinsing with physiological saline (0.9%) can remove a loose piece of dust, but never use ordinary tap water and certainly not eye drops intended for humans. Record what you observe in the horse dossier in EquiSight, including the date and a photo, so you can compare changes over several days.

Treatment: what does the vet do?

Treatment depends on the cause. For bacterial conjunctivitis, the vet will prescribe antibiotic eye drops, usually 3 to 4 times a day for 5 to 7 days. A blocked tear duct is flushed with a sterile solution via a thin tube. Uveitis requires a more intensive course of treatment: anti-inflammatory medication, sometimes corticosteroids, and regular check-ups, because untreated uveitis can eventually lead to blindness. In EquiSight you can save medication plans and follow-up appointments in the calendar, so you never miss a treatment moment.

Prevention: how to reduce the risk of problems

• Use a fly mask during fly season from May to September
• Ensure adequate ventilation in the stable: dust and ammonia fumes irritate the mucous membranes
• Check paddocks for protruding branches or barbed wire at eye height
• Feed hay preferably from the ground or from a closed hay feeder, not from a high feed rack
• Schedule an annual eye check with the vet, especially for older horses over 15 years of age

Monitoring watery eyes with EquiSight

Eye complaints are difficult to assess without comparative material. Using the photo feature in the horse dossier, you can take a consistent daily photo of the affected eye. EquiCoach analyses the description you enter and provides targeted questions you can put to your vet. This way you arrive at the practice well prepared and do not waste consultation time on basic information.