When talking with cow/calf producers in South Dakota many would agree that they typically see cases of pinkeye every year to some extent. According to an USDA study, producers stated that pinkeye was the second most common disease in calves greater than 3 weeks and the leading condition affecting breeding age beef heifers.
This author observed sales in 2010 in which calves that were sorted out for pinkeye typically would bring up to $100 per head less than calves without pinkeye. In addition to discounts at the sale barn, a 20 year review study indicated that calves diagnosed with pinkeye weighed from a range of 19-40 pounds less at weaning.
While Moraxella bovis is the typical infectious agent for pinkeye, an eye irritation is necessary for the development of the disease. Eye irritants can be factors such as plant material, ultraviolet light (sunlight), face, house and stable flies and dust.
In South Dakota the two top possible controllable irritants are most likely flies and plant material. For fly control see the past iGrow article “Fly Control Considerations.” When it comes to plant material a feasible solution may not be there. (Most papers would suggest clipping pastures.) However, in years of abundant sweet clover plant growth, control of sweet clover may be beneficial.
Flies not only serve as irritants, they also feed on secretions from the eye, thereby serving as a means of transmitting M. bovis from infected to non-infected animals. Face flies can remain infected with M. bovis up to 3 days following feeding on infected material. Under experimental conditions, disease transmission is uncommon without the presence of face flies and is common with flies present.
In addition to controlling possible irritants, vaccine may be another tool in prevention but should not be your only tool. Relying on vaccinations as the sole means of controlling pinkeye can be a disappointment because there are over 20 strains of the M. bovis bacteria and continuous mutation occurs in the bacteria. While vaccines contain the most common strains of M. bovis, they do not contain all the strains that occur. While bacterial strains in some vaccines offer cross-protection, others may not.
Early treatment of pinkeye is highly recommended. Not only are the chances of clearing up the infection greater, with less complications and scarring, but treatment also serves to decrease the shedding of the bacteria and the risk of transmission to other cattle. According to antimicSource: Heather Larsonrobial sensitivity studies, M. bovis is most often susceptible to oxytetracycline, penicillin, and sulfonamides. Your veterinarian is the best source of information about specific treatments for pinkeye.
As with most diseases in cattle, good prevention and early detection can minimize the losses pinkeye can have on your operation.
Source: Heather Larson