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ASK DOC BRAZIL: What causes pink eye in cattle?

Pink eye in cattle is an infectious disease that is caused by bacteria. These bacteria are transmitted by face flies.


This is why you often see pink eye outbreaks occurring during the spring and summer months, when fly populations are at their highest, and why you see rates of pink eye going down during the winter time as fly populations drop quickly.


The face flies feed on the secretions around the eyes of cattle, and as they do this they also spread the bacteria that causes pink eye from one animal to the next.


Pink eye vaccines: Which is most effective?


The bacteria causing Pink eye are Moraxella species. There are two common strains - Moraxella bovis and Moraxella bovoculi.


All the historic vaccines have been designed to prevent the Moraxella bovis strain. Now, we are starting to see an issue with vaccine failure. Because all the traditional pink eye vaccines have protected against only the Moraxella bovis strain, we are seeing more outbreaks caused by the Moraxella bovoculi strain.


Many people are still using the old vaccines, but they are becoming less effective because we have been selecting for the Moraxella bovoculi strain.


There is a new pink eye cattle vaccine on the market that protects against the Moraxella bovoculi strain produced by Addison Laboratories. In my practice I have seen it being very effective in herds experiencing outbreaks with the bovoculi strain, and would recommend asking your vet about this vaccine if you are experiencing pink eye issues.

How is pink eye in cattle treated?


If there is a pink eye outbreak in your herd, you should always consult your veterinarian for medical treatment and prescription medication. In my practice, I typically prescribe a long-acting oxytetracycline, either LA-200 or Noromycin 300. This is generally very effective for pink eye outbreaks.


How can I prevent pink eye in my herd?


In addition to the vaccination protocol explained above, there are other practical steps you can take to protect your herd against a pink eye outbreak. I strongly recommend fly and dust control.


The critical period is the spring and summer months as fly populations peak. By taking action to help control flies—such as insecticide impregnated ear tags, topical sprays or dust bags—you’ll be going a long way toward preventing pink eye outbreaks in your herd.


DISCLAIMER: This post does not constitute medical advice and should not replace the advice of your veterinarian. As always, please consult of your veterinarian regarding any questions you have about the health of your livestock, don’t ignore professional guidance.



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