Pink Eye in Cattle

Pinkeye in cattle is a painful & highly infectious disease, which can reduce growth rates and severely disrupt management. It will cause temporary blindness in many animals and permanent blindness in some. In a serious outbreak, a high percentage of the mob can be affected. The hot summer months are generally the worst time of the year for pinkeye.

The main cause in cattle is a bacterium called Moraxella bovis. Young cattle are particularly vulnerable, and there are a number of seasonal environmental and management factors that can predispose your cattle to a pinkeye outbreak. These include physical irritants such as wind, dust and pollen, strong UV light, nuisance fly, humid weather, thistles or other stalky vegetation, and feeding of hay. Bought in stock can introduce infection, while high stocking density can increase spread and poor nutrition can reduce the immune response to infection.

Damage to the eye often allows the bacteria in and then you get the characteristic symptoms of Pink eye. The first signs will be weepy eyes and an aversion to strong light. As the disease progresses the conjunctiva become red and inflamed and the eye becomes cloudy (leading to the term “Pink eye”). Pink eye is an animal welfare issue, causing prolonged and serious pain. An outbreak can lead to significant economic and production losses through depressed growth rates, loss of milk production, possible culls and disruption to seasonal grazing management. On top of that are the actual treatment costs of ointments and antibiotics.

Treatment Options

When dealing with a Pinkeye outbreak it is important to act quickly. This is in the interests of animal welfare, to minimise spread and to reduce production losses. The sooner you recognise it and treat it the more likely you are to have a successful outcome.

Consult us about treatments - most cases respond well to a course of pink eye ointment, some may require antibiotic injected into the conjunctiva and/or systemic antibiotics and some might even require surgery to save a badly damaged eye.

Note that bringing cattle into the yards for treatment can actually help spread the disease through exposure to dust and the close proximity of other animals.

Ideally, animals treated with antibiotics should be put out into clean pasture and left to recover at low stocking densities. Often however, by the time you realise you have an outbreak and not just a one off case, the disease with be well spread throughout the herd and it is going to be difficult if not impossible to spread infected cattle out at low stocking rates all over the farm.


There is no single action that will completely prevent the disease. A vaccine is available, but it is not particularly effective once an outbreak is established. If you suffer historically from pinkeye then a vaccination 3-6 weeks before the usual time an outbreak occurs is very effective. Other measures are recommended as follows:

  • Attempt to minimise exposure to dry, dusty conditions
  • Provide access to shelter from strong light
  • Control nuisance flies
  • Manage pasture to help prevent physical eye damage from thistle and similar plants 
  • Minimise close contact between cattle
  • Maintain good stock condition