Very much appreciated again!

Visit Toby's blog http://www.snorable.org

and altho this is pretty rare, there are also concerns with certain ailments and genetics where one or more of the three layers of the cornea begin to dissintegrate. Unfortunately I'm one of those; my brother has had corneal replacement on both of his eyes (he's in his early 70's) and I've been told that one of my eyes is beginning to show the same middle-layer weakening...but not to worry YET. There are usually replacement corneas available from cadavers.

If its a slowly developing ulcer its usually caused by eyelashes rubbing on the corneal surface (outer surface of the eye) and that can be from entropion (where the eyelid actually turns inward and causes the lashes to rub, upper/lower or both) or from distichia (errant hairs growing inward rubbing on the cornea...could be a few, could be many, could also be concurrent to entropia). Ulcers can form from dry-eye, where there isn't enough tear production to keep the eye moist and allow 'gliding' of the lid over the eye as the animal blinks. We often see the results of dry-eye in the goop (greyish usually) that collects in the eye, often after sleeping.

Then there is sudden trauma which is usually a scratch and that can be from a bush or something outside, from a toenail of another pet, or from the dog himself scratching an itchy eye...and that itch can be from several possibilities including but not limited to allergies, dry-eye, entropion or distichia, dirt in the eye from a windy day outside, temporary dryness caused by medication, direct and prolonged stream of air from close-by fan, etc etc etc.

So we usually deal with the 'results' or what we see...but it takes some expertise and some detective work to figure out the cause or causes. HTH