A variety of minor irritants can trigger a corneal abrasion in a dog: a run-in with the family cat, a scratch from a tree branch or bush while out on a hike, or even a bit of stray shampoo from a bath. Corneal abrasions are minor eye injuries, but seek treatment for them anyway -- they can develop into more serious eye injuries. Treatment usually focuses on pain relief and infection prevention.
Your Dog's Cornea
The cornea is the clear membrane covering the front of the eyeball. It's composed of three layers: the outermost epithelium; the middle layer, known as the stroma; and Descemet's membrane, which is the deepest layer. The cornea is transparent; the layers are visible only with the use of special stains that highlight specific cells for microscopic examination. When a few layers of the epithelium are damaged, a dog has a corneal abrasion or erosion. When the erosion extends beyond the epithelium and into the stroma, he has a corneal ulcer. If the erosion reaches into Descemet's membrane it becomes a descemetocele -- a serious condition.
Symptoms of Corneal Abrasions
An eye injury hurts, regardless of whether it's a light abrasion or a deep scratch. The first reaction you may notice is that your dog is keeping his injured eye tightly closed. Your dog may rub his eye with his paw or against the carpet to seek relief from the pain. A watery discharge may accumulate in the corner of the eye or may run down his face; if the injury becomes infected, the discharge may be colored.
Diagnosing Corneal Abrasions
The vet uses special dye strips to stain the dog's injured eye. After the vet washes the dye away, he'll use an ultraviolet light to look for dye that remains. Any that remains is adhering to the abrasion.
Treating Corneal Abrasions
Corneal abrasions are straightforward to treat. Antibiotic eye drops, administered every four to six hours, will minimize risk of infection. Pain medication will help relieve discomfort. If all goes well, your dog's abrasion should heal within three to five days.
Sometimes, despite treatment, a corneal abrasion will deteriorate to an ulcer or descemetocele. Administering medications as directed by your vet and making a followup visit within two or three days to check on his progress minimizes the chance that his injury will degrade. If your dog's corneal abrasion isn't healing properly, the vet may prescribe additional medication or recommend surgery.