Corneal ulcers in dogs can occur for a variety of reasons. The most common clinical signs associated with corneal ulcers are squinting, redness, and ocular discharge. A common reason for corneal ulcers are inrolling eyelids that cause eyelashes to rub on their cornea. Eyelashes can also grow in an abnormal direction and rub directly on the cornea. Both of these issues cause constant irritation to the corneal surface which can lead to chronic ulcers and corneal pigmentation. Corneal ulcers can also occur from more obvious issues such as a scratch from a nail or a foreign body such as a plant awn that may get lodged in the corner of their eye.
Uninfected superficial corneal ulcers will usually heal on their own within 3 days. During that time period however your dog will experience discomfort due to the many nerve endings that are present on the corneal surface. It is therefore recommended to see your veterinarian so they can prescribe eye medication such as atropine to help relieve the eye spasms and antibiotics to prevent any bacterial infection. Superficial corneal ulcers that do not heal by themselves within the 3 day timeframe are termed indolent ulcers and will need veterinary care to properly heal.
Deep corneal ulcers and melting corneal ulcers can lead to perforation of the eye and consequent blindness. These conditions will also present with the same clinical signs as superficial corneal ulcers. Deep corneal ulcers are too great in depth for the corneal layers to heal properly on their own while melting corneal ulcers present with infection that eat away the corneal layers.
Your veterinarian will use a special eye stain to determine if a corneal ulcer is present as well as to determine if it is superficial or deep. Infected corneal ulcers may need a culture and sensitivity to determine the appropriate antibiotic choice if empiric antibiotic therapy does not work.