Equine Eye Issues

Have you ever gone out to feed or catch your horse only to find his eye is weepy and swollen? It can be worrisome, for sure. Last week, this was the case with my middle-aged mare, Lee Lee. So I put a fly mask on her and watched the eye carefully for the next couple days. She wouldn’t let me touch the area at first, but the next day, I was able to clean around the eye with a saline solution. Things improved in a few days and she’s completely back to normal now.

In Traditional Chinese Medicine, eye health is related to the liver meridian. When there’s an imbalance in the liver meridian or when the liver, itself, is congested (often from toxin overload), problems with the eyes are common. Interestingly enough, I started all my horses on a detox supplement just a day or two after Lee Lee’s eye problem began. I wouldn’t be surprised if this was part of the reason the eye cleared up so quickly.

Equine eye issues should always be taken seriously. Even minor problems can turn into something more serious; if you’re ever in doubt, call your vet for a diagnosis and treatment.

But with that said, I thought I’d share some information on the most common eye issues seen in horses:


Corneal Ulcers

Corneal ulcers are caused from a break or tear in the surface of the cornea (outer layer of the eye). Ulcers often develop as a result of trauma–such as plant material or a branch scratching the eye. Symptoms include redness of the eye, tearing, squinting, cloudiness and/or irregularities in the cornea. More serious corneal ulcers can result in infection to the eye, which could lead to further complications.


Blocked Tear Ducts

This is an issue I dealt with in an older gelding we used to have. Blocked tear ducts are not especially painful for the horse, but they do result in almost continuous watery discharge, usually from one eye. They can occur for several reasons, including accumulation of debris or mucous, or from a structural problem, such as a narrow or damaged tear duct. A blocked tear duct can sometimes be dealt with by cleaning twice a day with a sterile solution and the use of a fly mask. But if it still doesn’t resolve, you may need to have your vet ‘flush’ the tear duct (this is what we did with Bo).


Conjunctivitis (Pink Eye)

Conjunctivitis is the inflammation of the inner lining of the upper and lower eyelids. This is one eye issue which can actually be contagious, so you may see all your horses developing this problem around the same time. Conjunctivitis can also be caused by a bacterial infection (often secondary to another illness), or possibly flies or environmental irritants.

Itching and irritation are usually the first signs of conjunctivitis, often followed by clear or yellowish discharge, swollen eyelids, closed eye or squinting, sensitivity to light and dust, rubbing the eye, and possibly head-shaking.

flies on horses face


Uveitis (Moon Blindness)

Uveitis is inflammation of the uveal tissue inside the eye. The symptoms of uveitis can be very similar to those of corneal ulcers, but may also include a constricted pupil and iris color changes. Uveitis can have many causes and Equine Recurrent Uveitis (ERU) is diagnosed when this condition reoccurs on a frequent basis, triggered by the immune system. ERU often leads to irreversible damage to the eye, and eventually, blindness. Early detection is important in ERU to slow inflammation and hopefully preserve the horse’s eyesight.

severe eye damage caused from ERU

severe eye damage caused from ERU

Traditional treatment of uveitis often involves other NSAID’s and steroid drops or medications, but there are also many holistic options, as discussed in this article.



With this condition, fluid builds, causing increased pressure inside the eye. This can lead to irreversible damage to the retina and optic nerve and eventual blindness. Glaucoma often occurs as a secondary effect of ERU, but it can occur on its own as well. The most common symptoms of glaucoma include redness, tearing, a cloudy cornea, dilated pupil, and vision loss.



Cataracts are opacities (cloudiness) occurring in the lens of the eye. They can range from minor (which cause few problems) to serious (which can cause blindness). Symptoms include a white lens or a white discoloration in the pupil opening. Cataracts can be a hereditary trait, or can occur from trauma and also ERU. Foals can also be born with cataracts, but this is likely from poor nutrition or toxin overload in the mother.

Large cataracts can cause inflammation inside the eye (a form of uveitis called lens induced uveitis). This is often treated with anti-inflammatories, but can also be treated with surgery.


Squamous Cell Carcinoma

This is the most common form of cancer in the equine eye region. In fact, I’ve featured a horse with this very condition in my Highlighted Horses section (read more here). Squamous cell carcinoma often occurs on the third eyelid, conjunctiva, cornea, or eyelids, but it can spread into the eye socket. Horses most at risk are those with white skin around the eyelids and older horses.

Lakota 3

photo courtesy of Sammi Colley

The tumor often appears as a pink, raised, roughened area, which can also involved sores which frequently open and drain around the eyelid. The tumor can spread into local tissues or even to other parts of the body, so it needs to be treated early and aggressively. Depending on the location, small tumors can often be removed, but some tumors require removal of the eye (as was the case with the horse shown above).


At-Home Treatment for Eye Issues

As I stated before, for more serious conditions, a trip to the vet is warranted, especially if you suspect something like uveitis or squamous cell carcinoma where early detection and treatment is crucial. But for more minor eye issues (such as what I recently experienced with Lee Lee), I recommend having several things on hand for at-home treatment.

With most eye conditions, a fly mask can be beneficial for both prevention and treatment. Masks can keep flies and other insects out of the eye and also reduce UV light (especially important for horses with light-colored skin around their eyes. I often use this one by Farnam, but there are many different brands and styles of fly masks available. When warmer weather and flies hit, I keep fly masks on my horses throughout the daylight hours.

Tulsa 5

I also like to keep saline solution on hand, as well as sterile gauze pads for cleaning.

Also, I will often use warm, steeped tea bags to place over the eye (if the horse will let me!). See more here about home remedies for eye issues.


Homeopathy for Eye Issues

Many people prefer to use homeopathy for minor eye issues, or to use in conjunction with more traditional treatments. The following homeopathic remedies can be used for eye problems (as well as many other problems):

  • aconite
  • arnica
  • belladonna
  • hypericum
  • pulsatilla
  • silicea
  • symphytum

Read more here about using homeopathy for equine eye issues.


Nutritional Support for Eye Issues

As I also stated before, eye issues can be related to toxins which are overloading the liver or even an imbalance within the liver meridian. Because of this, yearly or bi-yearly detoxes may be helpful, as well as ongoing nutritional support, especially for horses prone to eye problems such as ERI.

As with any health condition in the horse, your horse’s diet is important. Whole, natural foods are healthier than processed and high-molasses feeds. Healthy pasture and/or good quality hay should be the foundation of every horse’s diet. But also of importance for eye health are foods high in gamma linolenic acids, such as flaxseed or chia seeds.

Parsley and mint (fresh, dried, or tea) can be added to the diet to reduce swelling in the eye, and foods high in vitamin A, such as carrots, spirulina, or spinach can also be beneficial for eye health.

Some herbs which support the liver, and therefore will help with eye issues as well, include: dandelion, milk thistle, turmeric, lavender, and  mugwort.

Trace minerals are also important for overall health and should not be overlooked.





Sources and Further Reading:

Understanding Equine Vision and Eye Disease

Pink Eye in Horses

Conjunctivitis and Your Horse

Treating Eye Complaints with Homeopathy

Food For His Eyes

Managing Teary Eyes and Ocular Discharge in Horses





Hi! My name is Casie Bazay. I'm a mom, a freelance writer, and a certified equine acupressure practitioner.

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2 Responses

  1. Susan says:

    One of my horses comes up with a swollen, puffy, weeping eye every once in a while. I have had two vets look at him two different times (one of the vets specialty is eyes). Examination shows nothing wrong. Blowing out the tear duct doesn’t help. Different medications do nothing to heal either. I’ve come to the conclusion that it must be dirt. When he rolls, he really pushes his head into the ground, scratching every possible square inch of himself. I think dirt gets into that eye and then gets irritated. It’s my best guess!

    • Casie says:

      Could be. Might be worth trying a detox supplement and a fly mask though (if you’re not already using one). 🙂

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