Our eyes, just like dogs and cats, are one of the most complex anatomical features of the body.

Of all five senses, sight is the one most people would choose not to lose if given a choice.

It is a little different for dogs and cats because they have such keen senses. They have extremely good eyesight, but have even better ability to hear and smell. Losing their sight is not so devastating as long as they belong to a family, though it is still important.

The cornea is the transparent outer surface of the eyes, which is made up of three basic layers. The severity of injury or disease is determined by how many layers of the cornea are damaged. The deepest layer will actually allow fluid to leak out of the eye if it is damaged to the point of penetration.

The cornea is like a clear window which allows light in but is impenetrable to all other substances.

Milder corneal abrasions are only damage to the very superficial layer of the cornea.

A corneal ulcer is damage to deeper layers through the first layer, into the second layer, but not yet through the third and deepest layer.

There are several different causes of corneal ulcers. Trauma to the eye is the most common cause. Corneal abrasions and ulcers are fairly common.

It would seem dogs and cats would injure their eyes more than they do since they always lead with their noses. Their faces are normally very close to the ground, and they stick their nose out to examine everything, including each other. Fortunately, their eyelid reflexes are extremely fast and will close their eyes before most things have time to damage their corneas.

Other causes of corneal ulcers include bacterial infections, viruses and other infections. Some infections may originate in the eye. Corneal infections are secondary to some other systemic illness. Diabetes, Cushing’s disease and fungal infections can affect the eyes in a very negative manor. Weaker than normal corneas may be inherited, as in boxers.

The most common symptom of a corneal ulcer is simply when your pet seems to be holding the eye closed. There is usually some clear watery discharge at first.

If it goes untreated, they may develop a thicker discharge that contains pus. Dogs and cats will often rub their face with their paw or rub it on the floor.

Corneal ulcers are usually very painful. Everyone knows how uncomfortable just an eyelash in the eye is. I can only imagine how painful a scratch or ulceration of the cornea would feel.

Corneal ulcers are not always visible to the naked eye unless it has developed into a large lesion. Ulcers are diagnosed by applying a special stain in the eye which sticks to any abnormal corneal surface.

If an ulcer is present, the stain will show a bright green area on the surface of the cornea outlining the actual ulcer.

Treatment of corneal ulcers depends on the severity of the injury or infection. If there is an underlying cause, the systemic disease must be addressed first in order to treat the ulcer. Eye drops or ointment applied directly into the eye is the most common and effective medication to treat corneal ulcers. Antibiotic eye medication is used to treat and/or prevent infection in the cornea.

Another eye medication called atropine is used to reduce pain and scar tissue while the cornea is healing. Atropine also dilates the pupil in that eye so that the pet will keep the eye closed because direct light is too bright. This may cause a pet owner to think the corneal ulcer is not getting any better.

Any kind of eye lesion or injury should be followed closely to prevent it from making a change for the worse.

After just a few days, if the ulcer is not responding to the present treatment, some other medication or surgery may be necessary.

Grid keratotomy is a type of surgery used to scrape the edges of the ulcer in order to stimulate healing. The pet must be under general anesthesia for this type of surgery.

Once the corneal ulcer has healed, it may be beneficial to use an eye medication that contains steroids to help remove any scar tissue on the cornea if present.

It is extremely important to make sure the ulcer is completely healed because the ointment with steroids will likely make the ulcer much worse otherwise. That is why it is so important not to use eye medication prescribed for one pet on one of your other pets.

Everyone’s eyes, including our pets, are very sensitive and fragile. If your pet develops any kind of eye problem, see your veterinarian as soon as possible to ensure your pet lives a long, healthy and happy life.