Corneal ulcer is the correct medical term for any type of painful irritation to the corneal or outer protective layer of they eye. Corneal ulcers can happen from a variety of normal circumstances but they can also occur from specific medical conditions and diseases. In dogs the most common forms of corneal ulcers include scrapes and scratches of the eye or eyes from grass, debris or even the dog's own claws, entropion or eyelashes rolled inward to the eyeball, dry eye conditions resulting in abrasion or rubbing of the surface of the eye without lubrication and infections in the eye.
Corneal ulcers are typically noted by increased watering or tearing as the eye tries to soothe the irritated and painful area, refusal to open the eye or squinting, thick discharge from the eye or a red irritated appearance to the eye in mild cases. The dog may try to scratch at his or her eye continually or may rub the side of the head along the ground, on furniture or even against your hand or leg.
As the dog continues to scratch and rub, he or she will further irritate the outer protective layer of the eye and will cause the area to become rough as some cells are detached by the rubbing and scratching. This then provides the ideal circumstances for bacteria to get into the cells around the break, leading to more infections and irritation. The moist and relatively dark area of the eye is perfect for bacterial growth, especially if the dog is keeping his or her eyes closed.
Treatment of corneal ulcers first requires the determination of the initial source of the irritation. There may be a small grass seed, piece of debris or even an eyelash trapped in the eye that is causing the abrasion. Removal of this object is very important in allowing the cornea to heal. In cases where entropion or inward rolling of the eyelashes has occurred they need to be correctly positioned and fixed either with surgery or simple tacking to keep the eyelid right way out.
After the source of the irritation is removed the dog's own eye will immediately begin the healing process, however most vets will require application of antibiotic creams or drops to remove any bacteria that may be present. Typically there is no need to restrict the movement of the eye or the eyelashes and exposure to oxygen and light can help in the healing. In cases where the corneal ulcer is severe the third eyelid may be temporary pulled across the eyeball and tacked to the upper eyelid, forming a natural protective barrier to allow the eye to heal. Usually the dog will also have to wear an Elizabethan collar for a few days to prevent them from rubbing or scratching at the eye while it heals.
Moderate to severe cases of corneal ulcer that are not treated can cause vision loss for the dog or puppy so early treatment is very important. Usually after the initial treatment the vet will want to check the eye in 5 to 7 days to ensure there are no further complications or treatments required.