What is Pinkeye and How do I treat it?

Pinkeye is a painful, debilitating condition that can severely affect animal productivity. Pinkeye (infectious bovine kerato-conjunctivitis, or IBK) is a bacterial infection of the eye that causes inflammation and, in severe cases, temporary or permanent blindness. Most cattle producers will be familiar with pinkeye, but may not know how best to treat it and minimise its spread within a herd. Pinkeye can affect up to 80% of a mob, with affected weaner calves losing 10% of their body weight. When both eyes are affected, cattle may die from starvation, thirst and accidents. Occasionally, damage to the eye can be severe enough for blindness to be permanent. It is poor management and unacceptable from a welfare standpoint to allow severe cases to progress to this stage without treatment. The infection can spread very rapidly and the economic impact due to weight loss and lowered milk production can be considerable.

Pinkeye outbreaks are most frequently seen in summer and autumn when flies are more prevalent and ultraviolet radiation is high. This also coincide with the time when mature dry thistles and dusty conditions are more likely.

Signs of pinkeye will be familiar to most cattle producers. The first sign usually noticed is profuse tear secretions running down the face. The animal blinks frequently or holds the eye partly closed due to increased light sensitivity. There is also reddening of the membranes of the eye and in the margins of the eye itself. A white spot which identifies the site where an ulcer is forming then develops in the centre of the eye. Depending on the severity of the infection and whether or not treatment is started, this ulcer may expand and affect the whole eye or remain localised and start to heal. In severe cases, infection may spread to the inner chamber of the eye, which can fill with pus and cause the eye to appear yellow. If the ulcer involves the full thickness of the cornea, the fluid from the eyeball may be lost, resulting in a shrunken, sightless eye. Extreme care must be used when treating severe ulcers, as pressure on the eye may burst the eyeball. The cornea has very few blood vessels. When it is damaged, blood vessels must grow in from the edge of the eye to heal the damage. These blood vessels growing into the centre of the eye give the characteristic pink appearance of pinkeye. As recovery progresses, these vessels recede and the eye becomes a cloudy blue. After about 4 weeks the only evidence of infection may be a small white scar in the centre of the cornea. If the infection has been severe, the scar will be larger and there may be some permanent impairment of vision.

Non Veterinary treatments available at Parkside Produce  include Piliguard Pinkeye Vaccine - Pinkeye patches - Terramycin Powder or Aerosol

Extract from NSW DPI Primefact 336 (January 2007)