Pinkeye can and will attack every breed. I know that the white face cattle have a reputation for more eye problems, but in my experience I have found pinkeye to be an equal opportunity problem. It does not seem to target the white face animals any worse than solid blacks. I understand there may be some individual animals that are more tolerant. In my part of the country, Pinkeye seems to come in full force every few years. We may have three or four years with few outbreaks, and then all of a sudden there it is in full force, although we have done nothing different. I have had years when I have treated almost every single calf, and a few cows. There are many different types of Pinkeye, so unless you can identify the one your cows are afflicted with, the Pinkeye vaccines may not be of any use. My worst year ever just happened to come on a year I had vaccinated for Pinkeye. I think the cycle of bad year followed by a few good years is the main reason those who vaccinate after a bad year think it worked. It would likely have been a good year even had you not vaccinated. I have heard that they will become immune to Pinkeye once they have fought it off once. I believe this, because I usually do not have many older cows get it. The only thing I have found that seems to keep it from getting started is to control face flies. I do a pour on every three or four weeks when flies are at their worse. I also use a fly control mineral and have rubs out. I have not seen it yet this year, but it often seems to show up just about the time I think I have made it through the summer. One year it started just before I was ready to wean and sell. Very frustrating.
If they already have it, I give them a dose of LA300 or its generic equivalent. The patches are just too impractical on larger herds, and the medicine seems to always clear it up. I was once told to just let it run its course and most would get better on their own. Tried that and ended up with some blind calves. Yes, most got better, but those that did not sure cost me a lot more than a shot of LA300. I treat it as quickly as I can now. They will pass it from one animal to another, so if you can, it would probably be helpful to separate the affected animals.