Last week, at a herd test, I was asked by the farmer to have a look at a couple of calves which were weeping from their eyes, first noticed the previous day.

On close inspection, five calves from the group of 40 had profuse tearing in one or both eyes, with varying degrees of ulceration on the centre of the cornea. I treated the five calves, told the farmer to isolate them and went about my day.

Three days later, I returned to read the test, to hear that a further 10 of the group were affected, while the first five were fully recovered. In the end, there were 20 calves affected of the 40.

Infectious bovine keratoconjunctivitis, pink-eye, is the most common clinical disease of the eye in ruminants. It is caused by the bacteria moraxella bovis. It is mostly seen in younger animals, but can also affect older animals and is commonly seen in late summer or during housing.

Early signs include tear staining, conjunctivitis, swelling and closure of the affected eye, and can lead to ulceration of the cornea and potential blindness or rupture of the eye.

It is passed on through nasal and ocular secretions from carrier animals and can also be transmitted by flies. As seen in the above case, it is highly contagious and can spread rapidly through a group. Irritation and damage to the eye allows the bacteria to establish and progress to clinical disease.

As with all diseases, prevention is better than cure. Good management practices are of paramount importance to reduce or prevent spread of infection in cattle, sheep, and goats.

It is extremely important to isolate all infected animals from the main herd. Quarantine of newly purchased animals can also help avoid introduction of possible carriers. Proper fly control through regular insecticide treatments or impregnated ear tags can help prevent transmission and can reduce irritation from flies.

Reducing any potential ocular trauma is also very important. Avoid overcrowding and ensure plenty of room at feed and water troughs to reduce damage due to ear tags or hair.

Cutting overgrown pastures and hedges will reduce damage from grass awns and thorns. Reducing dust particles and irritants can also reduce ocular trauma.

Catching pink-eye early is key to treatment success. Any affected animals may need systemic antibiotics and possibly topical antibiotic treatment. It is important to intervene early and remove any affected animals to prevent spread. Contact your vet immediately if you are having any problems with pink-eye in your herd.

Michael Mc Donnell works at Riverview Veterinary Group, Bandon, Co Cork. Riverview Veterinary Group is part of XLVets. XLVets is a group of progressive practices who are working together to achieve a better future for agriculture and veterinary in Ireland. See www.xlvets.ie.