Cataracts in Horses
- Cataracts are areas of cloudiness inside the lens of the eye, and they can reduce vision or lead to blindness over time.
- In adult horses, cataracts commonly develop secondary to equine recurrent uveitis, while foals may be born with congenital cataracts.
- A cloudy-looking eye is not always a cataract. Corneal ulcers, uveitis, infection, and trauma can look similar and may be more urgent.
- Surgery is the only definitive way to remove a cataract, but not every horse is a good surgical candidate.
- If your horse has squinting, tearing, eye pain, sudden vision changes, or a new cloudy eye, see your vet promptly.
What Is Cataracts in Horses?
A cataract is a loss of normal transparency in the lens, the structure inside the eye that helps focus light onto the retina. Instead of staying clear, part or all of the lens becomes cloudy. That cloudiness can blur vision, reduce depth perception, and in more advanced cases cause major vision loss or blindness.
In horses, cataracts may affect one eye or both eyes. Some are present at birth or develop early in life, while others appear later. Adult horses often develop cataracts after ongoing inflammation inside the eye, especially equine recurrent uveitis. Older horses can also develop age-related lens changes.
For pet parents, the tricky part is that a "cloudy eye" does not automatically mean a cataract. The cloudiness may be in the cornea, the front chamber of the eye, or the lens itself. Because eye problems can worsen quickly, any new cloudiness, squinting, or vision change deserves a veterinary exam.
Symptoms of Cataracts in Horses
- White, gray, or bluish opacity seen within the pupil or deeper inside the eye
- Reduced vision, especially in dim light or unfamiliar spaces
- Spooking more easily, bumping into objects, or hesitating at gates, trailers, or jumps
- Difficulty tracking movement or finding feed, water, or footing
- One eye looking different from the other in brightness or clarity
- Signs of eye pain if uveitis is also present, such as squinting, tearing, eyelid swelling, or light sensitivity
- Behavior changes related to poor vision, including anxiety, head shyness, or reluctance to work
Mild cataracts may cause no obvious signs at first and are sometimes found during a routine eye exam or prepurchase exam. More advanced cataracts can interfere with riding safety, turnout confidence, and daily navigation.
When to worry: call your vet promptly if the eye looks newly cloudy, your horse is squinting, tearing, holding the eye closed, or seems suddenly less able to see. Those signs can point to uveitis, corneal ulceration, trauma, or infection, which may need same-day care.
What Causes Cataracts in Horses?
Cataracts in horses can be congenital, inherited, age-related, or secondary to other eye disease. In foals, cataracts are the most common congenital eye defect. Merck notes inherited cataracts in Belgian and Morgan horses, and Cornell has reported that American Quarter Horses appear over-represented for primary congenital or juvenile cataracts, supporting a genetic basis in some lines.
In adult horses, the most common cause is chronic inflammation inside the eye, especially equine recurrent uveitis. Repeated inflammation can damage the lens and surrounding structures over time. Trauma to the eye can also trigger cataract formation, and less commonly cataracts may develop after severe infection or other intraocular disease.
Sometimes your vet may describe a cataract as "incipient," "immature," "mature," or "hypermature." These terms describe how much of the lens is affected and how likely the cataract is to interfere with vision. The cause, the amount of inflammation present, and the health of the rest of the eye all matter when deciding what care makes sense.
How Is Cataracts in Horses Diagnosed?
Diagnosis starts with a complete eye exam by your vet, and many horses benefit from referral to a veterinary ophthalmologist. The goal is not only to confirm that the lens is cloudy, but also to determine whether the cloudiness is truly a cataract or a different eye problem. Your vet will look for pain, inflammation, corneal disease, pupil abnormalities, and signs of equine recurrent uveitis.
A typical workup may include a focal light exam, ophthalmoscopy, fluorescein stain if a corneal ulcer is possible, tonometry to measure eye pressure, and a dilated eye exam when safe to perform. If surgery is being considered, advanced testing may include ocular ultrasound and electroretinography to check whether the retina is healthy enough for vision after cataract removal.
This distinction matters because surgery can only help if the rest of the eye can still support vision. Horses with active or poorly controlled uveitis are often poor surgical candidates, and some cloudy eyes turn out to be corneal disease rather than a lens problem. That is why a hands-on exam is so important.
Treatment Options for Cataracts in Horses
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Exam by your vet
- Basic ophthalmic exam to confirm whether the cloudiness is likely lens-related
- Monitoring vision and comfort over time
- Management of the horse's environment for reduced-vision safety
- Referral discussion if pain, uveitis, or rapid progression is present
Recommended Standard Treatment
- Full exam by your vet plus referral to a veterinary ophthalmologist
- Detailed ophthalmic exam with dilation when appropriate
- Testing for concurrent uveitis, glaucoma, corneal disease, or retinal problems
- Medical management of inflammation if present, directed by your vet
- Structured recheck plan and discussion of riding and turnout safety
Advanced / Critical Care
- Board-certified ophthalmology evaluation
- Pre-surgical testing such as ocular ultrasound and electroretinography when indicated
- Cataract removal by phacoemulsification under general anesthesia
- Hospitalization, intensive postoperative eye medications, and multiple rechecks
- Management of complex cases with concurrent uveitis or other intraocular disease
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Cataracts in Horses
Bring these questions to your vet appointment to get the most out of your visit.
- Is the cloudiness definitely a cataract, or could it be a corneal problem, uveitis, or another eye disease?
- How much of the lens is affected, and how likely is this to change my horse's vision or safety under saddle?
- Do you see signs of equine recurrent uveitis or other inflammation that need treatment now?
- Should my horse be referred to a veterinary ophthalmologist, and how urgent is that referral?
- Is my horse still safe for riding, trailering, turnout, or competition with this level of vision?
- What monitoring schedule do you recommend, and what changes should make me call right away?
- Is cataract surgery a realistic option for my horse, and what testing would be needed first?
- What is the expected cost range for exam, medications, referral, and possible surgery in my area?
How to Prevent Cataracts in Horses
Not every cataract can be prevented. Congenital and inherited cataracts may be present from birth or develop early despite excellent care. Still, some risk can be reduced by protecting the eye and addressing inflammation early.
The most practical prevention step is fast treatment of eye disease, especially equine recurrent uveitis and trauma. Repeated inflammation is a major driver of cataract formation in adult horses. If your horse has tearing, squinting, light sensitivity, or a suddenly cloudy eye, see your vet promptly rather than waiting to see if it improves.
Daily observation also matters. Look at both eyes in the same light each day so you can spot subtle changes in clarity, pupil shape, discharge, or comfort. Horses with a history of uveitis may benefit from UV-protective fly masks and regular rechecks, based on your vet's advice. For breeding decisions, discuss family history and inherited eye disease concerns with your vet when congenital cataracts are present in a bloodline.