Today, I'm going to talk about corneal ulcers, especially in dogs. Not that cats do not get corneal ulcers, but, 80% of the cases I've seen so far happened in dogs. The causes of corneal ulcers? Well, the most common one is due to scratching either during fights, or the dog's been scratching the eye due to irritations. This happens mostly in those small breed dogs with flat face and big, bulging and protruding eye balls, e.g. shih tzu, pekingese and pugs. And, we do get lots of corneal ulcer cases, at least, I mean at least 2 to 3 cases a month. Some of them involved only the corneal surface. And, some of them got worst and the corneal sometimes ruptured, releasing the membrane underneath it (what we called the descemet's membrane which was named after the French physician Jean Descemet). When this happened, you could actually see the membrane bulging out from the cornea. This is what we terms as descematocoel.

In this photo, the ulcer is right in the middle of the eye. Sometimes, we could estimate the age of the ulcer by knowing the process of ulcer formation although it is not very accurate.
This is another Shih Tzu with a corneal ulcer in the middle of the left eye. The ulcer was not too bad compared to the one above. Sometimes, we just give the owner eye ointment and send the dog home. But, in severe cases, we have to conduct a surgery to pull the third eyelid of the dog to cover the unhealing ulcer so that the ulcer will be protected and have time to recover.

This is what we call a third eyelid flap whereby the third eyelid is pulled to cover the eye and temporarily suturd to the upper eyelid. The flap may have to be in place like that for up to 2 weeks. After 2 weeks, we'll have to release the flap and check the ulcer again. If everything turns out to be fine, then, the flap is removed.
Below is the ulcer after the removal of the 3rd eyeli flap. The ulcer is healing nicely and it clearity of the cornea it becomes normal once the ulcer has completely healed in another 1 to 2 weeks' time.

The most serious problem with unhealing corneal ulcers is uninviting bacterial infections. Some bacteria can produce a type of enzyme that prevents or melt the corneal. This would leads to unhealing ulcer. A much more major surgery have to be done to correct this condition.