Corneal ulcers develop when bacteria and/or fungi gain access to the interior of the cornea, generally as the result of trauma. This ‚Äútrauma‚Äù is generally a non-event and goes undetected. When we think of trauma we think of a catastrophic event. In many cases the traumatic event is simply a piece of hay that scratched the cornea.
Horses eating large round bales are at an increased risk because they prefer the better hay in the center and will bury their heads trying to reach the better hay. This creates an increased risk of scratching the cornea. Other possibilities include foreign bodies lodged in the eye, or blunt force trauma such as a stick, fence post, or even another horse. The cornea doesn‚Äôt have blood vessels, consequently these injuries don‚Äôt bleed and this often delays owners from noticing subtle signs of impending problems.