How does pinkeye spread?

This is where the face flies really play a role. They can carry the infection over a mile from animal to animal by feeding on the tears. Other flies like horn flies on the back and stable flies on the leg don’t carry the infection, but they do make cattle bunch out on pasture. If you see cattle bunching on pasture, you have a fly problem.

Why is it called pinkeye?

In the early stages, the eyeball is still clear, but it is tearing more down the side of the face. As the infection progresses, the eyeball starts to turn gray then white. This is the body fighting off the infection in the first few days. If the infection keeps going over a week, blood vessels start to invade onto the surface of the eye and the eye becomes “pink”. If you have an eye that is already pink, this infection has gotten a real head start!

How can we treat and prevent pinkeye?

An ounce of prevention is worth a pound of cure. Fly control is important. We know this is difficult when it rains every day. The fly population is just going to continue to explode through mid-September, so if you are having problems, call Dan at our office and he will help you sort out the best plan. We also use pinkeye vaccine to keep the infection from spreading through the whole herd. If you have to round up the herd to treat over 10%, it is worth vaccinating. For the treatment, it is important to start early with antibiotics, steroids on the eye and maybe a patch if the eye is painful enough.

We have everything you need to help battle this problem before the eye turns “pink”. Give us a call today at 605-428-5636 and let us help!


See pictures and learn more about the disease here.

South Dakota really only has two seasons: Winter and Fly season. With the heat and humidity over the last month, we are growing record numbers of flies. Along with those flies, we are seeing record cases of pinkeye.

How does pinkeye start?

This disease is an ulcer or a hole on the surface of the eyeball. This can start with any irritation to the eye including flies, tall grass, the tail of a neighboring cow, or dust. Once the ulcer is on the eye, then any type of bacteria can cause an infection. Flies often carry bacteria including Moraxella bovis, bovoculi and different types of mycoplasmas. All of these can create an infection that spreads quickly across the surface of the eye.

This product will not treat viral infections such as the common cold or flu. Unnecessary excess use or misuse of any antibiotic, such as Zithromax , can result in antibiotic resistant bacteria.