Now is the time to think ahead about preventive measures for pinkeye.
Pinkeye is the common name for Infectious Bovine Keratoconjunctivitis, a highly infectious disease that affects the eyes of cattle. It causes infection of the eye itself as well as inflammation of the conjunctiva (inside lining membrane of the eyelid). Typical symptoms include tearing from the infected eye, squinting, reddening of the membranes of the eyelid, and with advancing conditions, ulceration of the cornea, leading to the classic white, inflamed spot on the eyeball. If left untreated, this ulceration can lead to permanent scarring resulting in impairment of vision.
There are several conditions that can increase the chance for pinkeye to spread among cattle. From excessive dust in the air to cool, wet weather conditions says Ken Olson, SDSU Extension Cow/Calf Field Specialist.
"Wet conditions can be conducive to the spread of pinkeye," he said. "Damp ground provides increased breeding grounds for flies, particularly face flies, which are the primary carriers of the bacterial organism (Moraxella bovis) that causes the disease."
Additionally, Olson says increased moisture means greater forage production. Taller forage pokes cattle in the face, serving both as an irritant to the eye, as well as a vector for the spread of the M. bovis organism from one animal to another.
Prevention of pinkeye begins with fly control and can also include pinkeye vaccines.
"A variety of vaccine products are available, and all have potential to boost an animal's immune system against the M. bovis organism," he said. "While these vaccines often may not completely prevent pinkeye occurrence, they will reduce severity. Follow specific label directions for whichever product is used to get maximum benefit."
Olson says cattle should be vaccinated in the spring before fly season starts, because while the vaccine can be used later in the summer, in the face of a pinkeye outbreak, it will be much less effective.
Providing shade is another way to prevent pinkeye, as eye irritation from UV radiation can contribute to vulnerability of the eye to a pinkeye infection
"A final preventive measure is early treatment of initial cases to minimize spread from infected cattle to others," Olson said. "Unfortunately, cattle handling can be difficult in summer grazing settings. That said, treatment should be administered as promptly as possible to reduce the scale of outbreaks."
4-pronged Treatment Approach:
- Providing a topical anti-bacterial powder in the infected eye(s);
- Injecting a small amount (1 ml) of antibiotic into the layers of the membrane of the inner eyelid;
- An intramuscular injection of a long-acting oxytetracycline; and
- Gluing a patch over the eye to protect it from UV radiation.