Primary tools to help manage this contagious, costly disease in your dairy herd.
By Norman D. Stewart, D.V.M., M.S.
As cattle pinkeye season approaches, it’s important to put an effective management program in place and take the necessary steps to control this contagious, costly disease. Like a three-legged stool, vaccination, fly control and environmental management comprise the primary tools for managing pinkeye. They work together to provide an effective pinkeye control program and help maintain your animal’s health, productivity and profitability.
The first leg of pinkeye control is vaccination. Pinkeye is caused when bacterial organisms, such as Moraxella bovis, infect the surface and fluids of the eye. Pinkeye vaccines stimulate the production of antibodies in tears that bathe the eye, limit infection and reduce the severity of eye lesions.
Consider these three best management practices for pinkeye vaccination.
• Work with your veterinarian or animal health provider to identify a broad-spectrum vaccine that is effective against a wide variety of common infectious strains and isolates to address pinkeye on your operation.
• Vaccinate animals three to six weeks prior to the onset of pinkeye season to allow time for the animals’ immune system to develop an effective immune response.
• Administration times vary from product to product, so always follow label directions.
Because flies can spread pinkeye quickly, fly control is critical. Face flies can expose animals to different strains of Moraxella bovis by transporting bacteria from the eyes of animal to animal and traveling significant distances between herds. Other flies of concern are stable and horn flies.
Although these flies do not spread pinkeye, they are responsible for losses in milk production. Stable flies decrease milk production as a result of feeding on the lower body and legs of cattle, and horn flies can transmit mastitis-causing bacteria on the teat ends.
To reduce the effect flies have on milk production and the spread of pinkeye, consider these management practices.
• Use fly control products that are effective, long-lasting and easy to administer, and always follow label directions.
• For calves, heifers and cows, apply a low-volume pour-on for rapid knockdown of the existing fly population.
• Use an insecticide on the animal's premises, such as a microencapsulated product, that delivers superior, long-lasting control on a wide variety of surfaces in and around livestock facilities.
• Use additional fly control measures, such as ear tags in growing replacement heifers and back-rubbers, oilers and other devices as needed on pasture or in the milking parlor as cows exit the facility.
• Eliminate organic debris such as wet/rotting hay, straw, feed, silage and manure. These are ideal breeding grounds for stable flies.
• Conduct an audit of all of your facilities to evaluate existing fly and environmental control measures on the animals and premises, in addition to identifying areas for improvement.
• Reapply insecticides throughout the fly season.
Managing the environment is the third piece of your pinkeye control program. Management practices, such as pasture mowing, dust control and man-made or natural shades, are important to minimize eye irritants like pollen, seed heads, dust and ultraviolet light. These environmental factors cause irritation and physical damage, allowing infectious pinkeye organisms to attach to the surface of the eye.
Eye irritants also can cause the eye to tear. Tearing, watery eyes can attract face flies, which feed on the watery secretions from the eye and surrounding tissue. Flies can rapidly spread the infectious bacteria throughout the herd, which results in a dramatic and sudden increase of pinkeye.
Ultimately, managing pinkeye requires a planned attack. To maintain your animal’s health, productivity and profitability, remember the three-pronged approach of vaccination, fly control and environmental management this season.
Dr. Norman D. Stewart is a dairy technical services manager for Merck Animal Health. He lives in Illinois and can be contacted at firstname.lastname@example.org.