New forest eye is a highly contagious disease caused by Moraxella bovis that can spread rapidly during the summer months. It is more commonly seen in young stock than adults.
Head and nuisance flies can act as mechanical vectors for M. bovis and and dust can be a risk factor. The pain associated with this condition is more intense in strong sunlight.
Most cases are treated when there is obvious tear-staining of the face which becomes increasingly purulent, matting the lashes and hair of the face. There is marked pain when the eye is exposed to direct sunlight which can disrupt grazing patterns causing poor performance and even weight loss. If both eyes are affected, there can be temporary blindness and the affected animals tend to wander aimlessly about.
Other similar looking diseases include:
Prompt treatment is essential. Topical antibiotic eye cream is commonly used, but it is quickly washed out of the eye by tears, so needs to be applied frequently. Antibiotic injection into the conjunctiva around the eye is effective, and requires low volumes of drugs but can be difficult to achieve in fractious cattle and requires good restraint.
Single dose long acting oxytetracycline, florfenicol, tilmicosin or tulathromycin have all been reported to be effective but will prove more expensive.
In severe cases we can stitch the eyelids together under local anaesthesia with sedation if necessary to act like a bandage. The stitches are removed after two weeks. Temporary adhesive eye patches can also be used to provide protection. Severely affected cattle should be housed with ready access to food and water.
Treatment of all at-risk cattle with a single injection of long-acting oxytetracycline or tilmicosin could be considered in severe epidemics but there are no supporting field data and should only be used as a last resort.
Outbreaks of New Forest Eye may occur after the introduction of purchased stock therefore, whenever possible, all new stock should be managed separately as one group away from the main herd. Fly control using ear tags and pour-on insecticides is never absolute and repeated treatments are almost essential in warm weather. Development of immunity following infection is variable.
Further information can be found on NADIS website where you can read the full article written by Author: Phil Scott BVM&S DVM&S DIPECBHM CERTCHP DSHP FRCVS https://www.nadis.org.uk/disease-a-z/cattle/eye-conditions-in-cattle/
Photo’s kindly provided by NADIS