Animal Health

Time to be vigilant on pinkeye

By Jeff Cave

Pink-eye is a highly contagious, painful and debilitating disease that can severely affect animal productivity.

In summer, increased sunlight and dust make the eye more vulnerable to the disease. Long grass and flies help to spread the infection.

Pink-eye usually occurs in young cattle in their first summer. After this initial infection, cattle develop immunity to the disease but may remain carriers of the bacteria, Moraxella bovis, which potentially can lead to future outbreaks in following years.

The clinical signs of pink-eye include clear and watery tears, signs of irritation, an aversion to sunlight, reddening and swelling of the eyelids and cloudiness of the eye.

In a small percentage of cases, an affected eye may form an abscess and rupture, leading to permanent blindness.

While most affected eyes completely recover after three to five weeks, a number may be left with scarring on the surface.

Pink-eye can be treated with sprays, ointments, injections and patches or a combination of these treatments. Extra care should be taken when mustering cattle for the purposes of treatment for pink-eye, as factors such as dust and flies may enhance the spread of the disease.

Attention should also be taken not to confuse pink-eye with other conditions of the eye, such as a grass seed in the eye, eye cancer and other eye infections.

In many cases, an outbreak of pinkeye can be prevented through vaccination three to six weeks before the onset of the pink-eye season.

Other control measures include controlling fly numbers to limit the spread of bacteria from animal to animal, prompt segregation and treatment of pink-eye in affected stock and avoiding unnecessary yarding of cattle during periods where the risk of outbreak is higher.

For more information contact your private veterinarian or your Agriculture Victoria animal health staff through our Customer Service Centre on 136 186 or go to