Entropion

Ectropion is a termed used to describe a condition where the lower eyelid rolls outward. It is more often seen in breeds with excess loose skin that puckers outward, but nearly all breeds can potentially be affected. Ectropion may be categorized by the nature of the cause, congenital (the animal is born with the problem), a physiological problem that intermittently occurs when the animal is tired and cicatrical, where the problem occurs as a result of scarring in the area. The condition is usually bilateral (both eyes), but may just occur in one eyelid if the nerve control to that eyelid has been damaged.

The main problem arising from this condition is exposure keratitis, the eyelids fail to protect the cornea (clear surface of eye) as the tear film that normally covers the eye is disrupted. The tear film is responsible for supplying nutrients to the cells that comprise the cornea, as well as providing protection in the form of mechanical cleaning and immune system protection from infection. Thus a disruption will leave the cornea more open to infections and damage. This may present as corneal ulcers (break in surface), conjunctivitis (inflammation of lining) or keratoconjunctivitis sicca (not enough teat production).

Treatments is usually surgical. This procedure will usually involve cutting a V-shape wedge of tissue from the outer corner of the eyelid then closing the resultant wound to shorten the eyelid. Other surgical techniques may also be employed to remove excess conjunctiva (lining).