Cattle Diseases

A location on bovine chromosome 20 has been found to be involved in the origins of three of the most prevalent and costly bacterial diseases that affect feedlot cattle: pinkeye, foot rot and bovine respiratory disease (pneumonia), according to new ARS research.

Some livestock producers in Nebraska, Kansas and in the region say cattle have been having a tough go this summer with a particularly rugged case of pink eye.

Pink eye often stems from an injury. Eyes sometimes get irritated by tall grasses or they can get poked by a tree branch. The injured eye starts watering, and flies are attracted to the water in the eye. Flies can spread pink eye from animal to animal, and so can plant material.

Summer pink eye outbreaks are common, said Dr. Dale Grotelueschen, DVM, professor emeritus at the University of Nebraska-Lincoln Great Plains Veterinary Educational Center. He’s heard reports of excessive outbreaks this year.

It’s worse that past years, but it’s not a new strain of pink eye, according to Dr. Gregg Hanzlicek, veterinarian at Kansas State Veterinary Diagnostic Laboratory at Kansas State University.

“The predominate organism class has shifted some, but no new strain,” he said. “Pink eye is multifactorial, big time. Therefore control or treatment is never absolute in most cases.”

When looking to treat, he said to look for an underlying issue – what is compromising the cornea.

Pink eye, or infectious keratoconjunctivitis, can cause sensitivity to bright sunlight. Sunlight and high heat are causing complications this year. Inflammation of eye tissues can result in excessive tearing and pain, and squinting and partial or complete closure of the eyelids.

“Early treatment is highly important when cases begin to occur, to avoid severe complications,” Grotelueschen said.

As the disease progresses, the cornea can become inflamed and infected, making the eye cloudy with accumulated fluid, he said. Ulcerations on the surface of the cornea can occur, too, and cattle can be blinded temporarily. At worst, a cornea can scar and rupture, leading to loss of vision.

Fly control is a component of reducing risk for pink eye, but that can be difficult.

“Fly control is seldom complete, and is variable,” Grotelueschen said. “Forages in general are sufficiently tall in much of our grazing lands, to contribute to eye irritation.”

Producers can treat pink eye using the antibiotic recommend by their veterinarians.

“We have useful data that antibiotics result in faster cures, and that’s important because we also have evidence that pink eye is painful,” said Annette M. O’Connor, professor of epidemiology and chairwoman of the Department of Large Animal Clinical Sciences at Michigan State University and previously at Iowa State University.

Unfortunately, prevention is still not 100% possible. There are very few well-conducted studies on pink eye vaccines, and no well-executed studies show that available products are effective, according to O’Connor.

“Pink eye is a frustrating disease, there can be no doubt,” she said.

June brought more pinkeye cases than it typically does to the University of Nebraska-Lincoln School of Veterinary Medicine and Biomedical Sciences, according to faculty supervisor Dr. J. Dustin Loy. He reiterated the importance of early treatment.

“This reduces healing time, likely pain and discomfort, and would reduce bacterial numbers in infected cattle,” he said.

Controlling face flies is a big part of limiting the spread. Flies not only can transmit bacteria between animals, but their mouthparts irritate the eyes, Loy said.

Some published case studies of severe pink eye outbreaks in cattle show that the disease can resolve very soon after removing various fly attractants from the farm, such as nearby manure piles or decomposing feed, said Dr. Halden Clark, from UNL-Great Plains Veterinary Educational Center in Clay Center, Nebraska.

“Pink eye is a frustrating disease that is miserable to see cattle struggle with,” Halden said.

Amy Hadachek can be reached at editorial@midwestmessenger.com.  

Amy Hadachek is a freelance writer who lives on a farm with her husband in North Central Kansas. She's also a meteorologist and storm chaser. Amy can be reached at editorial@midwestmessenger.com.