Prevention is Key to Avoiding Pinkeye After Pasture Turnout
Involving multiple bacterial strains and risk factors, pinkeye is complicated, and there is no easy vaccine solution providing consistent efficacy.
May 20, 2025
Reduce cornea irritants to help prevent pinkeye.
by Iowa Beef Center, Iowa State University
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 Beef Specialist Chris Clark explains, “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? Prevention, prevention and early intervention.
Prevention points
- Reduce corneal irritants. The cornea provides a protective layer over the eye. When it is healthy, bacteria cannot attach. Irritants that damage the cornea allow bacteria to colonize and infection to occur. Common irritants on pasture include UV light, seedheads and dust.
- Control fly populations. Flies contribute to cornea irritation, but the primary role of flies in regard to pinkeye is carrying the bacteria from one animal to the next and facilitating transmission. Because flies can travel distances, the adage “your fly control program is only as good as your neighbor’s” bears truth. By taking steps in your herd, populations can still be significantly reduced. Multifaceted approaches are the most effective.
- Prioritize nutrition. 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 the 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 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 your veterinarian to develop a plan for dealing with cases,” Clark says. “Before using any medications, talk with your veterinarian about safety and legality for use in the eye, required dosing schedules, and required withdrawal times.”
Editor’s note: This article is provided by the Iowa Beef Center, providing extension and outreach on behalf of Iowa State University. [Lead photo by Iowa State University.]
Angus Beef Bulletin EXTRA, Vol. 17, No. 5-B
Topics: Health , Management
Publication: Angus Beef Bulletin
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