When visiting Greg and Jan Judy a few weeks ago, I asked Greg “What do you do about pinkeye?”
“We don’t treat it,” he said. “We found that if we treated it the cow got better in 2 or 3 weeks. If we didn’t treat it, the cow got better in 2 or 3 weeks.”
His response sounds like an old saying I heard from a South Dakota rancher, “You can treat pinkeye and it will get better in a week. Left untreated it will be better in 7 days.”
Causes of Pinkeye
Moraxella bovis is the bacterium responsible for pinkeye and is found in the eyes of recovered and healthy cattle alike. But the bacteria alone doesn’t necessarily cause pinkeye. It seems that there needs to be some kind of added irritation. So flies moving from cow to cow, tall grasses rubbing their eyes, dust and foreign objects in the eye, and ultraviolet (UV) sunlight are all considered potential factors in pinkeye. This last makes breeds without eyelid pigment more susceptible. Calves, especially bull calves, are also more likely to catch pinkeye while adult cattle develop protective antibodies on their eyes’ surfaces.
According to Kevin Gould of Michigan State University Extension, how well an animal works through pinkeye can be influenced by things like “nutritional imbalances, such as deficiencies of protein, energy, vitamins (especially vitamin A if the forage is lower quality) and minerals (especially copper and selenium).” He adds that, “The presence of other organisms such as the infectious bovine rhinotracheitis (IBR) virus, mycoplasma, chlamydia and Branhemella ovis will increase the incidence and severity of disease.
So what do you do?
Out of curiosity, I visited a listserv where farmers and ranchers were sharing their experience with pinkeye. All agreed that prevention was the best cure, describing the different rubs and fly tags they use. A South African farmer wrote, “What really worked for me was a farmers recipe I got mixing 5 liters of petroleum gel with 150 ml of Zeropar from Bayer Animal Health and rubbing it on the animal’s face, one handful will do.” (Zeropar is only available in South Africa and it is a dip or hand spray that controls itch mites, ticks, lice, blowflies and screw-worm infestations.) A Tennessee farmer said keeping cattle from spending too much time around water was a key. “If they have access to a pond, try to stop that because that only makes the flies worse and almost impossible to fight.”
One fellow complained that he thought the vaccines for pinkeye were “water,” and he’s not too far wrong. “The pinkeye vaccine has been disappointing as the sole means of controlling pinkeye,” says Gould. “There are over 20 strains of the M. bovis bacteria and continuous mutation occurs in the bacteria. While the vaccines contain the most common strains of M. bovis, they do not contain all the strains that occur.”
As For Treatment…
If you don’t go for no treatment at all, antibiotics are the most recommended treatment. Gould recommends tetracyclines at 4.5 cc per 100 pounds of bodyweight injected subcutaneously or in the thin membrane that covers the white of the eye (the bulbar conjuctiva). Sometimes a patch is added to keep the eye from being further irritated.
On another listserv I read a discussion of salt as a treatment. The writer said old timers told her to throw salt at the animals’ eyes. A respondent told her not to do that as it just makes the cows mad, and suggested, like Greg, to not treat it at all and the animals would get well.
Gould agrees with the farmers and ranchers on the importance of prevention and says, “Management practices that reduce the risk factors associated with pinkeye are the most effective tools in decreasing the incidence of disease.”
Gould suggests a variety of pours and rubs to kill and control flies, but for many of you, concerned about how dung beetles and other insects contribute to your soil health, that may not be an option. We’ve covered other methods, from culling to improve parasite resistant animals, to rotational grazing that takes into account the 10-21 day fly life cycle ensuring that animals move before the flies find a new host.
Here’s more on preventing Pinkeye: