The North Coast Local Land Services District Veterinarian team has issued a warning about Pinkeye in cattle on the North Coast following increased reports from livestock producers.

Pinkeye, blight or Infectious Bovine Keratoconjunctivitis (IBK) is an eye infection seen in cattle caused by the bacteria Moraxella bovis.

The disease is an important consideration for producers this time of year both in terms its negative animal welfare outcomes and the costs involved with treatments and lost production. Signs of the disease in cattle include:

• Increased tear production – cattle may exhibit a dirty stain down the side of their face due to the secretions running down from the eye.
• The cornea may become cloudy or bluish and a white spot or ulcer may appear in the centre of the eye.
• Some cases the ulcer may progress to affect the whole eye.
• In severe cases this infection can spread to the inner chamber of the eye.
• Affected animals may become temporarily or in some cases permanently blind.

The bacteria are shed in secretions from the eyes and nose of carrier animals and may be transmitted to other animals by flies. According to Dr Liz Bolin, District Veterinarian, there are a number of factors which can predispose cattle to pinkeye.

Dr Bolin said, “There are external factors such as an increase in fly numbers, the presence of grass seeds and thistles which can cause physical damage to the eye, dusty conditions or even bright sunlight.

“It can also be caused by conformation which is unpigmented eyelids and protruding eyes or certain environmental conditions in yard weaning – particularly overcrowding, dust or stress.”

Treatment options include

• Intraocular antibiotics, which must be purchased from a veterinarian. The ointment is delivered directly into the space between the eyelid and eye, a single treatment may be sufficient to halt the course of the disease.
• Antibiotic injections – can be effective however this may be more expensive and withholding periods must also be adhered to.
• Eye patches – may be used to protect the eye from further irritation from dust, flies and sunlight and can be used in conjunction with intraocular antibiotics.
• Segregating affected animals to minimise transmission to susceptible animals.
• Veterinary intervention such as third eyelid sutures or tarsorrhaphy may be warranted in severe cases.

Dr Bolin continued, “Treatment of pinkeye should be commenced as early as possible to minimise adverse animal welfare outcomes and to decrease the number of infective bacteria in the herd and limit the spread.

Prevention of pinkeye centres on minimising the risk factors:

• Reducing fly numbers using a registered fly control product.
• Avoiding yarding stock in dusty, dry conditions,.
• Encouraging dung beetles which bury the dung in which the flies breed.
• Controlling thistles.
• Genetic selection – pigmented eyelids and hooded eye conformation.

Dr Bolin advises that vaccination is important with a single dose vaccine dose given by injection under the skin or into the muscle of the neck and may be given at the same time as 5-in-1 or 7-in-1 vaccines.

Dr Bolin continued, “It is recommended that the vaccine be given 3-6 weeks prior to the onset of the pinkeye season and may be given to calves from as young as 1 week of age with a booster every 12 months recommended.”

Vaccination may be targeted toward young calves and replacements as the disease is much more prevalent in these classes of stock.

Source: Local Land Services. For more information on pinkeye or vaccination programs contact your private veterinarian or the North Coast Local Land Services District Veterinarian team.