Corneal ulceration or ulcerative keratitis is the most common ocular problem we see in horses. This is due to the fact that equine eye especially the cornea are so prominent and therefore prone to traumatic injury. Injuries to the cornea of the horse usually results from trauma. The traumatic incident may be anything from running into a fence post to getting sand, straw, or insect repellents in the eye. Other causes of corneal injuries in horses include eyelid problems, viral diseases, or low tear production. A horse with a corneal ulcer may present with any combination of the following clinical signs: tearing or ocular discharge, squinting, cloudy cornea and/or a red eye.
Any corneal ulcer can become infected with bacteria, fungus, or both. A shallow ulcer, when treated by a veterinarian, usually heals quickly, within 5-7 days, with minimal scarring. Corneal ulcers that become infected may be more difficult to treat and in some cases may require surgical intervention. In these cases, the ulcer or infection may become very deep or the cornea may start a process called “melting”.
A “melting” ulcer can progress in a matter of hours which can cause rupture of the eye if treatment is delayed. “Melting” ulcers and deep ulcers are considered emergencies. The ulcers may require intensive treatments for several days until healing begins. Often, inflammation of structures inside the eye accompanies deep or melting corneal ulcers which can be as vision-threatening as the corneal disease itself. With healing, melting ulcers and deep ulcers can result in noticeable scarring corneal scarring. If these scars are large, visual impairment may result. Performance may or may not be affected by the corneal scarring.
Deep ulcers or melting ulcers may sometimes require surgical intervention in addition to medical therapy to hasten healing and prevent rupture of the eye and to preserve the eye and vision. Procedures such as corneal grafting, conjunctival grafting, and amniotic membrane grafting can be utilized to provide structural support and in some cases a blood supply to aid in the healing process. These procedures will allow for healing of the cornea and they will form a dense scar in a matter of weeks.
While the horse is being treated for a corneal ulcer, it helps to keep the patient in a darkened stall and limit exercise. Hospitalization may even be necessary due to the frequency of treatments. Hay should be removed from overhead racks and fed on the ground. An eye saver mask, can be used to protect the eye from self trauma and flies. Exposure to dust can be minimized by sprinkling the stall with water several times a day and keeping the patient out of conditions of blowing dust.
If you have any questions about Equine Corneal Ulcers, please do not hesitate to call us at Eye Care for Animals.
