West Lafayette, Ind. — Next time beef producers look their animals in the eye, they might want to check for a common bacterial disease, a Purdue University beef specialist said.

Pinkeye causes inflammation, swelling and, if left untreated, the rupturing of the infected eye, said Ron Lemenager. The discomfort produces stress for the animal, which, in turn, affects its productivity.

The summer and early fall months are prime times for pinkeye transmission.

"Pinkeye is a disease that is very contagious," Lemenager said. "It is caused primarily by a bacteria called Moraxella bovis (M. bovis). A more recently identified strain called M. ovis can also cause pinkeye. While humans can get pinkeye, the disease is separate and distinctly different from the pinkeye cattle get."

In cattle, M. bovis and M. ovis often are spread by face flies. The flies move from cow to cow feeding on eye secretions, passing the bacteria to uninfected animals.

Once infection takes place the disease begins to manifest itself within a few days, Lemenager said.

"Early detection becomes important in this process," he said. "The first clinical sign that you're probably going to see is a runny eye. When the eye starts to water significantly, that becomes a trigger for a producer to be looking for pinkeye.

"In the very early stages of pinkeye, the membranes of the eye become red and swollen. As pinkeye progresses, the animal starts to squint and may walk around with a closed eye, because sunlight becomes a significant irritant to the infected eye."

Within two weeks of contracting pinkeye, an animal's condition worsens. "As we move further into the classical cases of pinkeye, the cornea will become cloudy and, eventually, you'll see a white spot or a spot that's bluish in color. The eye will create an ulcer," Lemenager said. "The ulcer is almost like a large pimple on the eye. If left untreated, the ulcer will rupture and the fluid in the eye will be expelled — at least to some degree. At that point, the animal will probably lose sight in that eye."

Traditional pinkeye treatments include intra-muscular or subcutaneous (Sub-Q) injections of oxytetracycline and covering the eye with a patch.

"You can also use an antibiotic injection under the eyelid," Lemenager said. "The concept here is that when you inject under the eyelid, the antibiotic will be released slowly over the eye and take care of the M. bovis organism."

In severe pinkeye cases, a veterinarian might be called in to suture the eye closed until the eye heals.

Producers can reduce the risk of M. bovis transmission by sanitizing their hands and farm equipment, controlling flies and weeds, and reducing dust, seedheads and pollen.

"I'm a big believer in the prevention of pinkeye," Lemenager said. "Since one of the contributing factors to pinkeye is face flies, if we can control face flies we can go a long way toward controlling pinkeye."

Control methods for face flies include insecticide treatments applied directly to cattle. Methods include insecticide-impregnated ear tags, dust bags that sprinkle insecticide over cattle as they walk under the bags, pour-ons applied to the animal's top line and sprays. Flies can develop resistance to insecticides, so producers should consult a local