Cattle Pinkeye: Infectious Keratoconjunctivitis Welfare and Management

Infectious bovine keratoconjunctivitis (IBK or pinkeye) is a painful eye condition in cattle causing significant welfare harm. Prompt treatment prevents permanent vision loss.

Key Facts

IBK is caused primarily by Moraxella bovis bacteria, with Moraxella bovoculi also implicated in recent outbreaks
Face flies (Musca autumnalis) are the primary mechanical vector, spreading bacteria between cattle
Clinical signs progress from excessive tearing and eye squinting through ulceration to potential eye rupture in severe untreated cases
Young cattle with no acquired immunity are most susceptible; UV light exposure exacerbates ulceration
Antibiotic treatment (oxytetracycline subconjunctival injection or long-acting systemic treatment) is highly effective when given early
Eye patches applied after treatment reduce UV light exposure and accelerate healing
Vaccination is available but offers only partial protection and should be combined with fly control
Prevalence of 2-5% in affected herds can be much higher during outbreaks, creating significant aggregate welfare impact

Welfare Considerations

IBK causes significant eye pain and photophobia (light sensitivity) that affects feeding behavior, movement, and social participation of affected cattle. Cattle with active corneal ulceration experience persistent, acute pain that is visible in their reluctance to open the affected eye, protective squinting, and withdrawal from normal herd activity. Permanent corneal scarring and vision loss occurs in cattle with severe untreated disease. The welfare case for prompt treatment is strong: early antibiotic treatment resolves most cases within days, while delayed treatment allows progression to irreversible damage. Systematic fly control reduces the primary transmission vector and prevents new cases during outbreak conditions. Daily observation of the eyes of all cattle allows early case detection that maximizes treatment effectiveness and minimizes pain duration.

What You Can Do

Observe cattle eyes daily during peak fly season and at regular welfare checks to detect IBK early
Treat affected eyes promptly with subconjunctival or systemic long-acting antibiotics as advised by your vet
Apply eye patches after treatment to reduce UV light exposure and accelerate healing
Implement fly control programs during summer to reduce the primary IBK transmission vector
Move affected cattle to shaded areas to reduce UV light exposure during treatment
Vaccinate calves in herds with endemic IBK problems before fly season begins
Discuss outbreak investigation with your vet if multiple animals are affected - husbandry and fly control review may be needed
Train stockpeople to recognize early IBK signs - tears, squinting, and eye cloudiness - and to report them immediately