By Jessica Crabtree with Dr. Jered Harlan
Aside from foot rot, infectious bovine keratoconjunctivitis, pink eye, is the next prevalent problem in cattle. Younger cattle seem to be more susceptible because older cattle have built protective antibodies on the eye surface as a result of previous exposure. Grazing cattle to dairy cattle can fall victim to the primary infectious agent of pink eye, a bacterium called Moraxella bovis. Although highly contagious and painful, pink eye is not fatal, but costs producers a great deal of money each year through deceased weight gain, decreased milk supply and treatment costs.
The bacterial disease causes infection and ulceration of the cornea and inflammation of the eye and skin surfaces lining the eye. If not properly treated, pink eye can result in permanent corneal scar and eyeball rupture leading to blindness. Research has shown that Moraxella bovis attaches to the cornea with hair-like protein extensions called pili. Toxins produced by this organism are believed to damage the cornea, leading to a cornea ulcer that looks like a hole or depression in the cornea.
Most common in the summer and fall, pink eye’s initial symptoms include swelling and redness of the conjunctiva, excessive tearing and squinting. Symptoms lead to decreased appetite due to pain and elevated body temperature. Within days a small opaque area will appear in the center of the cornea. By day six the entire cornea will be gray-white to yellow with deep central ulceration of the cornea. Recovery takes three to five weeks. In severe situations, ulceration and corneal rupture with loss of eye contents, cone-shaped bulging of the eye and blindness have occurred.
To read more pick up the April 2015 issue of North Texas Farm & Ranch.