Cattle Infectious Bovine Keratoconjunctivitis and Eye Welfare

Infectious bovine keratoconjunctivitis (pinkeye) is the most common ocular disease of cattle worldwide, causing corneal ulceration, pain, and blindness if untreated. Prompt antibiotic therapy and fly control are the most effective interventions.

Key Facts

Moraxella bovis and Moraxella bovoculi are the primary bacterial pathogens, with face flies acting as mechanical vectors between animals
Corneal ulceration progresses through grades 1 to 5 within days if untreated, with grade 5 involving globe rupture and permanent blindness
UV radiation increases susceptibility by damaging corneal epithelium — cattle at altitude and in high-sunshine environments have higher incidence
Subconjunctival oxytetracycline injection provides sustained local drug levels and is more effective than topical eye treatment alone
Vaccination against M. bovis pilins reduces incidence in some herds, though protection is not complete due to antigenic variation

Welfare Considerations

Corneal ulceration causes severe, continuous pain detectable through orbital tightening, blepharospasm, and reduced feed intake. Untreated animals lose condition rapidly as pain suppresses grazing behaviour. Blinded cattle face additional welfare burden from disorientation, inability to navigate to feed and water, and social vulnerability. Welfare-centred herds implement weekly eye inspection during at-risk summer months, treat all cases at grade 2 or higher with subconjunctival antibiotic, patch the affected eye to reduce UV exposure and fly access, and implement integrated fly control using ear tags and pour-on insecticides.

What You Can Do

Inspect cattle eyes weekly during summer months when fly populations and UV intensity are highest
Treat all cases at grade 2 ulceration or above promptly with subconjunctival antibiotic — do not wait for spontaneous resolution
Implement integrated fly control including insecticide ear tags, pour-on products, and manure management to reduce breeding sites
Consult your vet about vaccination programmes for herds with recurring high incidence of pinkeye
Provide shade structures in paddocks to reduce UV radiation exposure and corneal epithelial damage in susceptible cattle