Also known as Conjunctivitis, Infectious Bovine Keratoconjunctivitis, Keratoconjunctivitis, and Pink Eye, New Forest Eye is the most common eye condition seen in cattle.
It is caused by the bacterium Moraxella bovis, and can be seen in cattle worldwide regardless of age – from calves to adult cows. However, it is more common among youngstock and yearlings.
While cattle can become infected in isolation via bacteria from the environment, it is typically “carrier cows” that enter the herd that allow it to spread rapidly.
It is most common in areas of high fly population such as low lying, wet pastures. This is because flies are able to spread the bacteria easily as they feed on the secretions from a cattle’s eye. Dustier conditions and tall grass are also associated with higher occurrences of the disease.
What are the Clinical Signs?
Later signs are easier to spot but it’s important to look out for any early signs to avoid the spread and severity of the disease.
Early signs include dislike of bright sunlight, excess tear production along with staining on the side of the face, and closed eyelids.
Later signs include a cloudy and white appearance to the surface of the eye, the development of an ulcer that is commonly seen in the center of the eye and may raputre, and noticeable pain that may result in lower weight gain.
What is the Best Treatment?
There are three treatment options to consider, best suited depending on the severity,
Topical antibiotics are popular for their low cost and simplicity. These ointments are preferred when early signs are spotted and before ulcers get too deep. They are also preferred to powders due to their better effectiveness, and higher lasting power (up to 48 hours).
If the condition has progressed, injected antibiotics are paramount. These can be injected into the conjunctiva, or into the muscle of vein. Keep in mind that while subconjunctival antibiotic injections can prove to be particularly useful, it is recommended that a veterinary surgeon administers them.
Given enough time if the case of New Forest Eye is mild it will heal naturally. However, early treatment is still recommended to prevent scarring and limit the likelihood of spreading the infection to other cattle.
How Can New Forest Eye Be Prevented?
New Forest Eye can be prevented through chemical solutions and proper management. Prevention is primarily based on good fly control. If fly numbers are only moderate cattle ear tags can be effective. Another option is to use pour-ons. However, as these need to be applied regularly to be effective ear tags are the preferred option.
Proper management includes keeping the susceptible cattle away from the areas in which New Forest Eye can thrive, including where there are fewer flies. Checking cattle at least twice daily during the risk period is also necessary. Partial closure of the eyelids and signs of tearing can indicate that there may soon be a problem.