Entrophin is a condition which causes one or both lower eyelids of lambs to turn inwards.

The in-turned hairs of the lower eyelid rub and scratch on the cornea of the lamb’s eye, causing irritation and damage to the cornea.

This in turn leads to the lamb's eyes weeping continuously in large amounts, with the hair under the eyelid becoming noticeably wet.

The lamb’s eye will also appear to be half or fully closed as the condition gets worse.

Entrophin can, in some cases, recover of its own accord, but, in general, without treatment, the cornea becomes cloudy and ulcerated, leading to permanent blindness.

Treatment

Slightly infected cases can sometimes recover by gently pulling the eyelid back manually into its correct position.

A slight pinch of the skin under the eyelid will often help it from reverting inwards and may need to be repeated on a number of occasions.

In more severe cases, lambs can be treated by injecting approximately 1ml of a long-acting antibiotic under the eyelid or, alternatively, by placing a surgery clip or specially designed staple below the eyelid to draw out the skin of the lower eyelid.

Lambs should be monitored closely, especially where the eyelid is drawn back

In very serious persistent cases, a strip of skin may need to be surgically removed by a vet from under the eyelid.

Lambs should be monitored closely, especially where the eyelid is drawn back manually to ensure the eyelid does not revert inwards again.

The condition puts lambs off their normal behaviour, with some lambs not following their ewe or suckling insufficiently to become hardy in their first few days of life.

Replacements

Previous studies into entrophin suggest it is a heritable disease, although the exact cause is unknown.

For this reason, the advice generally given in most circumstances is not to retain lambs that contract the condition for replacements to minimise the risk of the disease occurring again in future generations.

In severe cases, it may require a change of ram where this is the known link.