Corneal Ulcers in Cows
- See your vet immediately. Corneal ulcers are painful and can worsen fast, especially when flies, dust, sunlight, or rubbing keep irritating the eye.
- In cows, many corneal ulcers are tied to infectious bovine keratoconjunctivitis (pinkeye), but trauma from hay, seed heads, dust, or foreign material can also start the problem.
- Common signs include tearing, squinting, light sensitivity, a cloudy or blue-white cornea, discharge, and a visible white spot or defect on the eye surface.
- Your vet often confirms the ulcer with fluorescein stain and checks for deeper damage, uveitis, or risk of rupture before choosing treatment options.
- Typical 2025-2026 US cost range for farm-based care is about $150-$600 for straightforward cases, with severe ulcers, repeated visits, hospitalization, or surgery sometimes reaching $800-$2,500+.
What Is Corneal Ulcers in Cows?
A corneal ulcer is an open sore on the cornea, the clear outer surface of the eye. In cattle, this is often seen as part of infectious bovine keratoconjunctivitis (IBK), commonly called pinkeye. Merck Veterinary Manual notes that central corneal ulceration is a key early sign of IBK in cattle.
These ulcers are painful. A cow may squint, tear heavily, avoid bright light, or keep the eye partly closed. As the ulcer deepens, the cornea can become cloudy, swollen, or white-blue. In more serious cases, the eye can scar, rupture, or lose vision.
Not every corneal ulcer in a cow is caused by infection alone. Mechanical irritation from grass awns, hay stems, dust, or rubbing can damage the corneal surface first, and bacteria may then take advantage of that injury. Because the eye can change quickly, early veterinary care matters.
Symptoms of Corneal Ulcers in Cows
- Excess tearing or wetness below the eye
- Squinting, blinking, or holding the eye closed
- Sensitivity to sunlight
- Red or inflamed conjunctiva
- Cloudy, blue, or white cornea
- Visible white spot, pit, or defect on the cornea
- Yellow-white material in or around the ulcer
- Eye discharge that becomes thicker or more obvious
- Corneal blood vessels growing toward the lesion
- Bulging eye surface, marked swelling, or sudden vision loss
Mild tearing can turn into a serious eye problem quickly in cattle. Worry more if your cow is keeping the eye shut, the cornea looks cloudy or white, the ulcer seems larger from day to day, or the eye looks swollen or misshapen. Deep ulcers and ulcers with severe pain, uveitis, or risk of rupture need urgent veterinary attention.
What Causes Corneal Ulcers in Cows?
In cows, corneal ulcers commonly develop with pinkeye (IBK). Merck Veterinary Manual describes IBK as the most common manifestation of infectious keratoconjunctivitis in cattle, with central corneal ulceration as an early hallmark. Moraxella bovis is the classic bacterial pathogen associated with IBK, although other organisms and contributing factors may be involved.
Physical irritation often sets the stage. Seed heads, coarse hay, dust, wind, and foreign material can scratch the cornea. Face flies can spread bacteria and also irritate the eye. Ultraviolet light exposure, lack of shade, and tall stemmy pasture can make outbreaks more likely.
Some ulcers become more complicated because the cow keeps rubbing the eye, flies continue landing on it, or treatment is delayed. Once the corneal surface is damaged, deeper inflammation, corneal edema, and secondary infection can follow. That is why herd-level management and fast treatment of affected cattle are both important.
How Is Corneal Ulcers in Cows Diagnosed?
Your vet diagnoses a corneal ulcer by combining the eye exam with special staining. Fluorescein stain is commonly used to confirm a break in the corneal epithelium and outline the ulcer. Merck Veterinary Manual notes that fluorescein is used to evaluate corneal epithelial integrity and can also help identify leakage if the cornea has ruptured.
During the exam, your vet may look for corneal thinning, white or yellow stromal infiltration, corneal edema, blood vessel growth, and signs of reflex uveitis. These details matter because a shallow ulcer and a deep ulcer are not managed the same way. Your vet may also check whether pinkeye is the likely underlying cause based on herd history, season, fly pressure, and the appearance of the lesion.
In straightforward field cases, diagnosis is often made on-farm. More advanced testing or referral may be needed if the ulcer is deep, melting, not healing, or if the eye may need a flap procedure, tarsorrhaphy, or other surgical protection.
Treatment Options for Corneal Ulcers in Cows
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Farm call and eye exam
- Fluorescein stain to confirm the ulcer
- Systemic labeled antibiotic selected by your vet when IBK is likely
- Pain and inflammation control, often with an NSAID if appropriate
- Protective eye patch and shade recommendations
- Basic herd management advice for flies and irritants
Recommended Standard Treatment
- Complete farm eye exam with fluorescein stain
- Systemic antibiotic therapy commonly used for IBK under veterinary direction
- NSAID for pain and inflammation when appropriate
- Eye patch placement, with recheck to assess healing
- Targeted topical ophthalmic medication if your vet feels repeated handling is feasible
- Isolation or easier observation of affected cattle and herd prevention planning
Advanced / Critical Care
- Urgent re-evaluation of deep, melting, or nonhealing ulcers
- Hospital-based or specialty-level ophthalmic assessment when available
- Procedures such as third-eyelid flap, conjunctival flap, or temporary tarsorrhaphy
- More frequent monitoring and supportive care
- Additional medications for severe inflammation or complicated infection as directed by your vet
- Management planning for vision preservation, welfare, and production impact
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Corneal Ulcers in Cows
Bring these questions to your vet appointment to get the most out of your visit.
- Does this look like a superficial ulcer, a deep ulcer, or pinkeye with ulceration?
- Did the fluorescein stain show a small defect or a larger area of corneal damage?
- Is this eye at risk of rupture or permanent vision loss?
- Which treatment options fit this cow and our farm setup best: conservative, standard, or more advanced care?
- Would an eye patch help this case, and when should it be changed or removed?
- What pain-control options are appropriate for this cow, and what milk or meat withdrawal times apply?
- Should we separate this cow or check the rest of the herd for early pinkeye signs?
- What pasture, fly-control, or shade changes could lower the risk of more cases?
How to Prevent Corneal Ulcers in Cows
Prevention starts with lowering both eye irritation and pinkeye spread. Face-fly control is a major part of that plan. Cornell extension materials note that keeping face-fly numbers low helps reduce pinkeye spread, and thresholds around 10-15 flies per face have been used in integrated pest management programs. Depending on your farm, your vet may suggest ear tags, sprays, rubs, manure management, or a combined fly-control program.
Pasture management also matters. Clipping tall seed heads, reducing sharp stem exposure, and limiting dusty conditions can help protect the cornea from scratches. Shade can reduce ultraviolet light stress, which is one of the known risk factors for IBK outbreaks.
Check cattle early and often during fly season. Prompt treatment of tearing or squinting animals can reduce suffering and may decrease transmission within the herd. If pinkeye is a recurring problem on your farm, ask your vet about a herd-level prevention plan that matches your region, housing, pasture conditions, and production goals.