What is a corneal ulcer in dogs?
The cornea is the clear covering of the front of a dog’s eyeball. A corneal ulcer, or eye ulcer, is an erosion through the corneal surface.
Corneal ulcers for dogs can be superficial, affecting just the surface layer, or deeper, involving the entire thickness of a dog’s cornea.
Deep corneal ulcers can be particularly serious for dogs, as they can lead to leakage of the fluid from inside the eye and irreparable damage if the internal lining of the cornea (Descemet’s membrane) ruptures or is exposed.
What causes corneal ulcers in dogs?
The most common cause of a corneal ulcer is trauma. It could be from a cat scratch, laceration, chemical burns (such as shampoo) or simply from the dog rubbing its face on a surface such as a carpet.
Disorders affecting the eyelids can lead to drying or trauma to the cornea, making it more vulnerable to ulcers. Breeds with excessive skin folds such as Shar Peis are prone to entropion, a condition where the eyelids turn in, and the hair rubs on the eye, causing corneal trauma. Some dogs develop corneal abrasions or ulcers due to abnormal eyelashes or warts on their eyelids.
Short-nosed (brachycephalic) breeds of dogs such as French Bulldogs and Pugs are at increased risk of trauma to their eyes due to their size and prominence on the face.
Less commonly, bacterial or viral infections and some other diseases can make dogs more susceptible to corneal ulcers. These include epithelial dystrophy (an inherited weakness of the cornea) in Boxers, Keratoconjunctivitis Sicca (dry eye) in which the cornea becomes dry due to a lack of tear production and hormonal diseases such as Cushing’s disease, diabetes and hypothyroidism.
Symptoms of corneal ulcers in dogs
Corneal ulcers are very painful for dogs and can cause some noticeable signs. Some of the most common corneal ulcer symptoms for dogs include:
- Squinting or a closed eye
- More tears or fluid than usual
- Rubbing or scratching around the eye
- Cloudy appearance in the eye (due to fluid buildup)
Diagnosis of corneal ulcers in dogs
Minor ulcers or other wounds to a dog’s eye aren’t always visible without using specialist vet equipment.
Your vet will look for corneal ulcers in your dog using something called fluorescein stain. This is a specialist medical dye, which turns green and highlights any ulcers. This stain is particularly useful for spotting larger ulcers; smaller ones may be more easily detected using ophthalmic lights and filters.
Chronic or non-healing ulcers may require swabbing to check for resistant bacterial infections.
Healing of a dog’s corneal ulcer
The healing process for a corneal ulcer depends on the cause, size, location and depth.
A straightforward corneal abrasion or superficial ulcer will generally heal in 3-5 days.
However, despite the application of topical antibiotics, some ulcers will continue to worsen. This may be due to abnormal healing processes, underlying health conditions or repeated trauma. Your dog should therefore be regularly re-examined to ensure that healing is progressing normally.
An infected or deep ulcer will take longer to heal and may progress to loss of vision or leakage of fluid from the eye.
The cornea does not usually contain blood vessels, but the body will help promote healing by forming new blood vessels across the surface of the eye. This process is called neovascularisation and will speed the healing of the ulcer. If this is excessive, further drops (corticosteroids) may be required to help clear the cornea following healing of the ulcer.
Often, after large or deep corneal ulcers, a small scar will remain on the cornea. This is generally of minimal consequence to the dog and will not affect their vision significantly.
Corneal Ulcer Treatment for Dogs
Medication is required to prevent bacterial infections from developing whilst the ulcer heals. Antibiotic eye drops are usually given 4 times a day. Lubricating eye drops may also be used to soothe the eye and keep it moist until the ulcer is completely healed.
Sometimes, atropine drops will be prescribed to dilate the pupil. This helps to relieve the pain but can make your dog sensitive to light.
Anti-inflammatory pain medication may also be prescribed, depending on your dog’s discomfort and any other illness or medications that may affect their use.
Additional medications may be required for deep or infected ulcers, such as systemic antibiotics and topical plasma drops.
In some cases, deep ulcers may require surgery to prevent the eye from leaking fluid.
Refractory superficial ulcers may require a procedure to remove abnormal healing tissue and promote successful healing. Most of our clinics offer grid keratotomy/debridement to help this.
You can view a list of our prices for Eye Surgery here.
If your dog is displaying any of the above symptoms and you suspect they are suffering from an eye ulcer, you should seek advice from a veterinary surgeon as soon as possible. Book a free consultation here.