Corneal Ulcers in Dogs and Cats

Eyes can reveal a lot of information about our pets – whether they are happy, angry, scared, or even sick. Eyes are very complex and even have their own immune system separate from the rest of the body. Because of this, many treatments for eyes must be topical and cannot always rely on oral or systemic medications. As with any body system, they can have their own set of problems.

A very common problem that can occur is that the cornea can be scratched. The cornea is the transparent outer layer of the front of the eye. It refracts and transmits light and protects the inner structures of the eye. The cornea can become scratched easily – for example, your pet can run into some brush/branches, they can get scratched by another animal or housemate, and they can have underlying health conditions that can damage the cells of the cornea. Damage to the cornea can cause several of the cornea’s layers to be scratched away, leaving a divot, often referred to as an ulcer or erosion.

The typical signs of having a corneal ulcer are squinting, redness, tearing, and rubbing the face. If these signs are observed whether you are sure of any previous trauma, it is best to schedule an appointment in a timely manner. Your veterinarian can evaluate the structures of the eyes with an ophthalmoscope and may even check ocular pressures and tear production. Often, a fluorescein dye is used to further visualize the cornea. Because the cornea is transparent, damage to the layers of the cornea cannot always be seen with the “naked eye.” This dye will stick to an ulcer and help confirm the presence of an ulcer, as well as the width and depth.

Many uncomplicated corneal ulcers heal quickly with the aid of ophthalmic drops/ointment given several times daily in addition to pain medication. If your pet is scratching or rubbing at their face, an Elizabethan collar, or cone, can be considered to prevent additional damage to the eye. For more complicated ulcers that have been present for a long time, are very deep, or have surrounding inflammation of the cornea itself, there are additional therapies and procedures that can help these to heal appropriately. It is not recommended to try to self-treat your pet’s eye without the guidance of a veterinarian, as several types of eye medications can do a corneal ulcer more harm than good.

During the treatment process, it is critical to monitor the eye closely. Depending on the type and chronicity of the ulcer, a recheck will be recommended two to seven days after the initial evaluation, and regularly thereafter until the eye is completely healed.

There are serious complications that can develop if the ulcer does not heal appropriately. One such possibility is known as a melting ulcer, which occurs when an infection causes the cornea to soften and deteriorate. Another severe form of a corneal ulcer is a descemetocele. This is an ulcer that is so deep that all that is left of the cornea in this location is one cell layer between the outside of the eye and the inside of the eye. As you may imagine, this causes the eye to be extremely fragile and makes it very vulnerable to rupturing: this is considered to be an ocular emergency.

In addition to making sure that the ulcer heals appropriately, your veterinarian will also consider the underlying cause. Traumatic injuries are most commonly to blame, but there are also certain abnormalities such as dry-eye, hair growing in the wrong place along the eyelid, viruses, and even congenital breed conditions that can predispose to damage to the cornea.

If you are worried that your pet may have a corneal ulcer, the safest approach is always to reach out to your veterinarian so that the eye can be evaluated. Your vet will develop and discuss with you a plan for treating and monitoring that will give your pet’s eye the best chance of healing comfortably and completely.