Pinkeye Problems

By Becky Mills
Progressive Farmer Contributing Editor

Pinkeye is a disease that just doesn't play fair. And it's getting trickier all the time.

A simple vaccination used to be the answer and producers could get along for years with no pinkeye in their herds. But times have changed and, in some cases, so have the bacteria that cause pinkeye.

Commercial vaccines are targeted for the bacteria Moraxella bovis, but Doug Ensley, veterinarian for Boehringer Ingelheim says Moraxella bovoculi is also now appearing in cattle's eyes.

"If you still have pinkeye in your herd after vaccinating regularly, have your veterinarian swab your cattle's eyes. If you find the Moraxella bovoculi bacteria is present, a vaccine can be made especially for your cattle. But continue to give the commercial vaccine, too."

Max Irsik, University of Florida beef cattle veterinarian, says there are a lot of negatives that come with pinkeye. And unfortunately, it's something almost every cattle producer has experienced at one time or another. Cattle hurt and don't want to leave the shade. Gains go down. In the case of cows, milk production, body condition and even pregnancy rates suffer. All of which means fewer pounds to sell, not to mention a major price hit if eye lesions are visible.

While treatment is important, prevention is always better. Today, veterinarians promote a three-pronged approach to keep the disease out of the herd.

1. Fly control. Face flies and horn flies are well-known for helping spread the bacteria that causes pinkeye. Cattleman Herkie Davis puts a lot of thought and effort into keeping cows as fly-free as possible.

Davis uses an automatic sprayer to mist cows with insecticide as they use the mineral feeder.

Unfortunately, he says the spray, along with the ear tags he used, lost some of their effectiveness. Davis attributed the problem to resistance and immediately initiated management changes aimed at getting better control.

He started by switching to fly tags with an organophosphate rather than a pyrethroid. It worked. "They killed 100% of the flies," the Clarksville, Tenn., producer happily reports. He puts a tag in each ear of cows and one tag per animal on yearlings.

2. Pasture Management. Seeds from mature grass, sharp stems from grass or weeds and briars can all irritate the eye. This opens the way for pinkeye bacteria. Davis rotates pastures every seven days and keeps them cut so there aren't weeds or seeds in the environment to irritate cattle's eyes. He says this type of oversight also helps prevent over-grazing and keeps down dust (another risk factor for pinkeye).

Veterinarian Ensley also recommends providing shade in pastures and pens. He says excessive exposure to sunlight can irritate cattle's eyes.

3. Vaccinations. It's important to vaccinate cattle with a product made specifically for pinkeye. Ensley encourages producers to vaccinate as early in the spring as possible, before flies come out.

Commercial vaccines are targeted for the bacteria Moraxella bovis, but Ensley says Moraxella bovoculi is also now appearing in cattle's eyes.

"If you still have pinkeye in your herd after vaccinating regularly, have your veterinarian swab your cattle's eyes. If you find the Moraxella bovoculi bacteria is present, a vaccine can be made especially for your cattle. But continue to give the commercial vaccine, too."

Ensley also says it's important to stay current on IBR (infectious bovine rhinotracheitis) vaccinations, as IBR can trigger eye lesions.

WHEN PREVENTION ISN'T ENOUGH

The best way to confront pinkeye is to treat early. Left untreated, this disease can be extremely uncomfortable for the animal and can lead to blindness.

To catch problems as soon as possible, always be on the lookout for runny or swollen eyes. Next, check for a cloudy or creamy look to the eye. That can be followed by ulcerations in the cornea.

Irsik says an injection of a systemic antibiotic given according to label directions is usually the first step in treatment. He adds there are some topical sprays made for pinkeye treatment that have shown fair results.

Your vet may inject antibiotics into the eyelid or possibly under the conjunctiva, the layer of thin membrane under the eyelid and covering the white part of the eyeball. This is a specialized technique that should only be done by a veterinarian.

Cattlemen can help with treatment by isolating the infected animal(s) from the rest of the herd. This is the only way to prevent flies from spreading the bacteria.

In addition, the veterinarian advises protecting the eye, if possible. "Cover it or sew it shut so it isn't exposed to dust, flies and sunlight," he says, adding one option is to use a denim patch held on with back tag glue.

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