B - Infectious bovine keratoconjunctivitis

Question 1

Aetiology

Answer 1

• Also called “New Forest Eye”, “Pink eye”
• Moraxella bovis …
• Gram-negative, aerobic bacterium
• Can be commensal
• Other pathogens involved: Mycoplasma boviculi

Question 2

Epidemiology

Answer 2

• Most prevalent in summer
• Musca autumnalis
• Infectious epizootic
• > 50% population within 2 weeks
• Carrier remains afterwards (main source infection)
• Decreased market value and weight gain

Question 3

Pathogenesis

Answer 3

• 0-24: bulbar conjunctival oedema/hyperemia
• 24-48: shallow central corneal ulcer
• If untreated, full clinical expression…
• Ulcer enlarges, deepens, > neutrophils
• … corneal abscess

Question 4

Clinical presentation

Answer 4

• Ulcerative keratoconjunctivitis: blepharospasm, epiphora, corneal oedema, deep ulceration, neovascularisation
• Painful
• May have vision loss
• Less severe cases: recovery in 1-3 weeks

Question 5

Diagnosis

Answer 5

• History, clinical signs and laboratory diagnostics (PCR)

Question 6

Treatment

Answer 6

• Topical Cloxacillin ointment
• Tetracycline (2º mycoplasma spp)
• Bulbar conjunctival injection
• Systemic NSAIDs
• No topical steroids (ulceration risk)
• Tarsorrhaphy

Question 7

Prevention

Answer 7

• Insect repellent

Question 8

What kind of lesion is seen? What disease is it suggestive of?

Answer 8

Infectious bovine keratoconjunctivitis. Deep corneal vascularization, cellular infiltration, ulceration, and diffuse corneal oedema are noted