Pink Eye in Sheep: Infectious Keratoconjunctivitis Symptoms & Treatment
- Pink eye in sheep, also called infectious keratoconjunctivitis, is a contagious eye disease that causes tearing, squinting, light sensitivity, and a cloudy or blue-white cornea.
- Many sheep recover with timely care, but delayed treatment can lead to corneal ulcers, rupture of the eye, permanent blindness, weight loss, and spread through the flock.
- Common triggers include infectious organisms such as Mycoplasma conjunctivae, Chlamydophila pecorum, and Moraxella ovis, plus irritation from flies, dust, plant awns, bright sunlight, and commingling at shows or sales.
- See your vet promptly if the eye looks white, blue, ulcerated, swollen, or very painful, or if multiple sheep are affected at once.
What Is Pink Eye in Sheep?
Infectious keratoconjunctivitis, often called pink eye or contagious ophthalmia, is a painful, contagious eye disease of sheep. It affects the conjunctiva and cornea, so pet parents may notice red eyes, heavy tearing, squinting, and a hazy or cloudy surface over the eye. In sheep, corneal ulceration may be present, but it is not required for the condition to be diagnosed.
This condition is most common in younger animals and often shows up during warmer months, especially when sheep are exposed to flies, dust, bright sunlight, or the stress of transport, fairs, and commingling. One or both eyes can be affected. Appetite may drop because the eye is painful and vision is reduced.
Pink eye in sheep is not always caused by one single germ. Several infectious agents have been associated with outbreaks in small ruminants, including Mycoplasma conjunctivae, Chlamydophila pecorum, and Moraxella ovis. Because more than one factor can be involved, your vet may recommend different treatment and management steps depending on severity, flock size, and how quickly the disease is spreading.
Symptoms of Pink Eye in Sheep
- Excessive tearing or wetness below the eye
- Squinting, blinking, or holding the eye shut
- Light sensitivity and seeking shade
- Red or inflamed conjunctiva
- Cloudy, blue, or white cornea
- Mucus or pus-like eye discharge
- Corneal ulcer or visible defect on the eye surface
- Reduced appetite, poor thrift, or isolation from the flock
- Bulging, ruptured, or shrunken eye with vision loss
Early cases often start with tearing, squinting, and sensitivity to sunlight. As inflammation worsens, the eye may look cloudy or blue-white, and discharge can become thicker. Some sheep keep eating and acting fairly normal at first, so mild cases are easy to miss.
See your vet immediately if the cornea looks very white, yellow, or deeply ulcerated, if the eye appears swollen or ruptured, if the sheep cannot open the eye, or if several animals develop signs over a few days. Fast action can reduce pain, limit spread, and lower the risk of permanent blindness.
What Causes Pink Eye in Sheep?
Pink eye in sheep usually develops when infectious organisms and eye irritation overlap. Organisms linked with infectious keratoconjunctivitis in small ruminants include Mycoplasma conjunctivae, Chlamydophila pecorum, Moraxella ovis, and less commonly other bacteria or parasites. In some outbreaks, more than one organism may be involved at the same time.
The eye also becomes more vulnerable when the surface is irritated. Important risk factors include flies, dust, plant awns or foxtails, ultraviolet sunlight, and stress from shipping, shows, sales, or mixing groups. Trace mineral deficiencies, especially copper or selenium deficiency, may also make outbreaks harder to control.
Because the disease is contagious, infected eye secretions matter. Sheep can spread organisms through close contact, shared handling equipment, and conditions that bring animals nose-to-nose or eye-to-eye. That is why one lamb with a watery, squinting eye can turn into a flock problem if management changes are delayed.
How Is Pink Eye in Sheep Diagnosed?
Your vet usually starts with a careful eye exam and flock history. They will look for tearing, conjunctivitis, corneal haze, ulcers, discharge, and whether one or both eyes are affected. They may also ask about recent transport, fair exposure, new additions, fly pressure, dusty bedding, or pasture plants that could irritate the eye.
Diagnosis is often based on clinical signs, but testing can be helpful when cases are severe, recurrent, or spreading quickly. Your vet may collect samples from the eye for cytology, culture, or molecular testing to look for organisms associated with infectious keratoconjunctivitis. This can be especially useful when treatment has not worked as expected or when a flock-level plan is needed.
Your vet may also use fluorescein stain to check for a corneal ulcer and assess how deep the damage goes. That matters because treatment choices, handling, prognosis, and the need for follow-up all change if the cornea is ulcerated or at risk of perforation.
Treatment Options for Pink Eye in Sheep
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Farm or clinic exam focused on the affected eye
- Topical ophthalmic antibiotic selected by your vet when appropriate
- Pain control or anti-inflammatory medication if indicated
- Isolation from the flock when practical
- Shade, reduced dust exposure, and fly control
- Monitoring for worsening cloudiness, ulceration, or poor appetite
Recommended Standard Treatment
- Veterinary eye exam with fluorescein stain to check for corneal ulceration
- Prescription systemic and/or topical antimicrobials based on your vet's judgment
- Anti-inflammatory medication for pain and swelling when appropriate
- Temporary eye protection such as patching or tarsorrhaphy in selected cases
- Separation of affected animals and a flock management plan for flies, dust, and sunlight
- Recheck exam if the eye stays cloudy, painful, or closed
Advanced / Critical Care
- Urgent veterinary assessment for deep ulcer, corneal perforation risk, or severe pain
- Diagnostic sampling such as culture or PCR when recurrent or outbreak-associated
- More intensive eye protection or surgical procedures for severe corneal damage
- Systemic medications, supportive care, and repeated follow-up exams
- Flock outbreak investigation with treatment protocols, segregation, and prevention planning
- Consideration of humane culling decisions in nonresponsive or blind animals, guided by your vet
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Pink Eye in Sheep
Bring these questions to your vet appointment to get the most out of your visit.
- Does this look like infectious keratoconjunctivitis, or could trauma, a foreign body, or another eye disease be involved?
- Is there a corneal ulcer, and how serious is the damage right now?
- Which treatment option fits this sheep and our flock setup best: conservative, standard, or more advanced care?
- Should this sheep be separated, and for how long?
- Do other flock members need to be checked or treated because of exposure?
- What fly control, shade, bedding, or pasture changes would help reduce spread on our farm?
- Would testing the eye discharge help if this case is severe, recurrent, or not improving?
- What signs mean I should call back right away, such as worsening cloudiness, loss of appetite, or possible rupture?
How to Prevent Pink Eye in Sheep
Prevention focuses on lowering both infection pressure and eye irritation. Good fly control, cleaner air in barns, less dust around feeders and bedding, and reducing exposure to sharp seed heads or foxtails can all help. Shade matters too, because bright ultraviolet light can irritate the eye and make outbreaks worse.
Management changes are especially important during summer and around stressful events like weaning, transport, fairs, and sales. Avoid mixing unfamiliar groups when possible, and watch new or returning animals closely for tearing or squinting before they join the flock. Early identification and treatment reduce pain and may decrease transmission within the group.
Work with your vet on a flock plan if pink eye keeps returning. That plan may include reviewing mineral status, improving pasture and housing conditions, tightening biosecurity, and deciding when diagnostic testing makes sense. There is no widely accepted, reliably effective vaccine for pink eye in sheep, so prevention usually depends more on management and fast response than on vaccination.