Pinkeye is a costly disease to cattle owners and at this time of year, cattlemen seem to see the largest amount of affected animals.
The primary cause of pinkeye is a bacteria called Moraxella Bovis. There are many strains of Moraxella Bovis, that we see every year. Other causes of pinkeye may be mycoplasma, pseudomonas and acheoplasma, all of which are bacteria, which can cause pinkeye looking lesions. There may also be viral causes such as IBR, known as rednose, that may cause pinkeye looking problems. Trauma, weeds and grasses may cause some corneal abrasions, which also appear to look like pinkeye.
The symptoms of pinkeye include slight tearing at first to one or both eyes, and then a small cornea ulcer will appear in the center of the cornea. The cornea will become cloudy or blue in a couple of days, if the disease is not treated. The eye may rupture, or develop a yellow fluid inside the eyeball. These advanced lesions will lead to a white spot on the cornea when the healing process is completed.
Prevention of pinkeye is management. Cattlemen need to keep pastures clipped, keep down dust and use a good fly control. A good choice of mineral will also help.
There are also several commercial vaccines available. A good commercial vaccine will have several strains of Moraxella incorporated into it. Cattlemen should ask their veterinarian which works best in their area. I believe they should vaccinate for pinkeye by the middle of June and some may require boosters.
If cattle are vaccinated with a pinkeye vaccine, and it appears that an outbreak has occurred, there may be other problems, such as, one of the bacteria that may be causing the problem. This can be determined by culturing the eyes of the affected cattle during an outbreak. In many cases today in our area the bacteria mycoplasma has been the major cause of pinkeye when cattle have been vaccinated with pinkeye vaccine containing Moraxella Bovis.
There are some cases when cattlemen make a vaccine for their cattle by using the cultures taken off their farm, these are called autogenesis vaccines, and they can be made fairly economically.
Treatment may include antibiotics, such as oxytetracycline, which there are many forms of today. The use of ceftiofur has also been beneficial. These antibiotics work well in the earliest stages of the disease when cattle first start tearing.
Subconjunctival antibiotics work well in this area, you should not use a long acting oxytetracyline for subconjunctional injections because it is very irritating.
Remember it is always best to consult your local veterinarian when you have any questions about eye problems. My best advice is to treat pinkeye in its earliest stage.
Dr. Rusty Waide, DVM has been the owner of Buffalo Veterinary Clinic for 21 years.