Definition: Infectious keratoconjunctivitis of cattle.

Characteristics: Blepharospasm, conjunctivitis, lacrimation, and varying degrees of corneal opacity and ulceration

In cattle, Moraxella bovis is the most commonly recognized cause of infectious keratoconjunctivitis. Most other ocular infections of cattle are characterized by conjunctivitis and minimal or absent keratitis. The primary differential diagnosis is infectious bovine rhinotracheitis (IBR), which causes severe conjunctivitis and edema of the cornea near the corneoscleral junction, but corneal ulceration is uncommon. Infection with IBR or other microbes may increase the severity of infection with M bovis .

Clinical Findings: The disease usually is acute and tends to spread rapidly. One or both eyes may be affected. In cattle, dry, dusty environmental conditions; shipping stress; bright sunlight; and irritants such as pollens, grasses, and flies tend to predispose to or exacerbate the disease. Flies also serve as vectors. In all species, young animals are affected most frequently, but animals of any age are susceptible. The initial signs are photophobia, blepharospasm, and epiphora; later, the ocular discharge may become mucopurulent. Conjunctivitis, with or without varying degrees of keratitis, is always present. Appetite may be depressed due to ocular discomfort or visual disturbance that results in inability to locate food. The clinical course varies from a few days to several weeks unless complicated by other diseases.  EL

Oscar Duarte is a field representative for ABS Global and can be reached at This e-mail address is being protected from spambots. You need JavaScript enabled to view it