 | Dr. William Morland graduated from Kansas State University in 1970 with a doctorate in veterinary medicine. He and his wife, Dr. Laura Morland, founded the hospital in 1974. Dr. Morland is a large-animal practitioner. He also owns the Flying M Ranch. He enjoys working with his own cattle and back grounding calves. His pets other than his cattle include two Cairn terrier named Bandit and Dandy. |
Animals, Reptiles & Insects
2013-05-29 11:51:44
What causes pinkeye in cattle?
A-Infectious bovine keratoconjunctivitis, more commonly known as pinkeye in cattle, is a contagious bacterial infection of the eye. Pinkeye is caused when bacterial organisms such as Moraxella bovis infect the surface of the eye. Multiple strains of Moraxella bovis have been identified, each capable of creating pinkeye in cattle. The bacteria attach themselves to the tissues of the eye and cause inflammation and ultimately ulceration of the cornea which results in pain and can lead to possible blindness.
While bacterial organisms like Moraxella bovis are the root cause of pinkeye in cattle, face flies are the primary vector responsible for spreading the bacteria from animal to animal. Face flies travel from animal to animal. They feed on the watery tearing from cattle's eyes. When they do so they spread the bacteria that can cause pinkeye from animal to animal. Since face flies can visit several animals a day they can rapidly spread the pinkeye bacteria throughout a herd.
Seed heads, dust, pollen and UV light are environmental factors that can increase trauma to the eyes of cattle. These irritants can scratch the cornea of the eye and allow for easier attachment of the Moraxella bovis bacteria. Traumatized eyes will result in an increase in the tearing of the eye; increasing the attraction of the face flies that can spread the pinkeye causing bacteria.
This is why fly control and environmental management are key components of a pinkeye prevention plan.
Pinkeye in cattle easily costs producers an average of $100 a head due to reduced weight gain, added treatment costs and discounts on sale day. University research has shown that pinkeye can reduce weaning weights in calves as much as 40 to 60 pounds.
The first leg of control is vaccination. The best pinkeye vaccines stimulate the production of antibodies in tears that bathe the eye, limit infection and reduce the severity of lesions. To allow adequate development of immunity, vaccinate animals three to six weeks prior to the onset of pinkeye season.
The second key to preventing pinkeye is fly control, because pinkeye can be spread rapidly by face flies that transport bacteria from the eyes of one animal to another. Face flies can travel significant distances between herds and can expose animals to many different strains of Moraxella bovis.
Effective fly control requires customization to your production system. There are several best management practices that most every producer should follow to reduce the impact flies have on the spread of pinkeye.
• Treat animals of all ages and their premises with an effective, long-lasting and easy to administer insecticide
• For calves and cows (dairy cows under 21-months of age), apply two insecticide fly tags (one in each ear) per animal, in addition to a low-volume, long-lasting pour-on for rapid knockdown of the existing fly population. Reapply the pour-on as needed
• For premise control, use an insecticide 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 as necessary, such as back-rubbers, oilers and other devices that can be used on pasture
• When ear tags lose their effectiveness, remove them and apply a final dose of a low-volume pour-on
• If you believe a product is not working, contact the manufacturer and your animal health provider to discuss the situation and get help
• Reapply insecticides throughout the fly season, and always follow label directions.
The environment is the third area of focus in preventing pinkeye. Management practices such as pasture mowing, dust control and man-made or natural shades are important to minimize eye irritants, such as pollen, seed heads, dust and ultraviolet light.
These environmental factors cause eye irritation and physical damage, allowing infectious pinkeye organisms to attach to the surface of the eye. These irritants can also cause the eye to tear. Tearing, watery eyes can attract flies, which feed on the watery secretions from the eye and surrounding tissue and spread pinkeye-causing bacteria.
