Prevent cattle from getting pinkeye after pasture turnout

As herds are being turned out on pasture, most calves will get an immunity boost for select diseases through a vaccination program. 

However, as Iowa State University Extension and Outreach Beef Specialist Chris Clark explained, “Arguably the most common health nuisance on pasture – pinkeye – doesn’t have an easy vaccine solution with consistent efficacy. In part, this is because pinkeye is complicated, involving multiple bacterial strains and risk factors.”

The solution is prevention and early intervention.

Prevention points

The cornea provides a protective layer over the eye, and when it is healthy, bacteria cannot attach. Irritants which damage the cornea allow bacteria to colonize and infection to occur. Common pasture irritants include UV light, seedheads and dust.

Flies also contribute to cornea irritation, but the primary role in regard to pinkeye is carrying the bacteria from one animal to the next and facilitating transmission. Because flies can travel long distances, the adage “your fly control program is only as good as your neighbor’s” bears truth. 

By taking preventative steps in one’s herd, fly populations can still be significantly reduced. Multifaceted approaches are the most effective.

Multiple macronutrients and micronutrients are essential for an effective immune response. A well-balanced mineral program is important in keeping the herd healthy. 

Mineral supplements can become costly, so a solid understanding of mineral levels in available feed and water can help reduce some costs without sacrificing animal performance.

Early intervention

Check cattle regularly, and watch closely for early signs of infection. Once clinical signs are observed, initiate treatment as soon as possible to minimize complications and severe cases.

Treat cattle with systemic antibiotics labeled for pinkeye and be diligent in following label directions. 

Weigh animals to ensure appropriate dosing. 

Use good injection site practices to ensure optimal drug absorption.

Adjunct therapy such as eye patches, stitching eyelids shut and subconjunctival injections are sometimes used in addition to systemic antibiotics. Evidence is somewhat inconsistent regarding efficacy of these practices. 

Eye patches have been shown to speed corneal ulcer healing, but for best results, leave a spot open to facilitate drainage and airflow when applying. Pinkeye increases sensitivity to UV light, so shade can be helpful for animal comfort. 

Pain associated with pinkeye may warrant the use of an anti-inflammatory as well. Topical ointments and sprays are also sometimes used.

“As with all health challenges, work closely with a veterinarian to develop a plan for dealing with cases,” Clark said. “Before using any medications, talk with a veterinarian about safety and legality for use in the eye, required dosing schedules and required withdrawal times.”

Sherry Hoyer is a communications specialist for the Iowa Pork Industry Center and Iowa Beef Center and Chris Clark is the Iowa State University Extension and Outreach beef specialist. This article was originally published by Iowa State University Extension and Outreach on May 20.