Dogs' eyes are susceptible to several conditions, one of which is corneal ulcers. With a corneal ulcer in dogs, it's important to get them treated as soon as possible. In this blog post, we'll discuss what a corneal ulcer in dogs is, the symptoms to look out for, and how they're treated. We'll also provide some tips on how you can help prevent your dog from getting a corneal ulcer in the first place. So if you're concerned about your pup's eyes health, keep reading!

What is the cornea?

The cornea is the clear, outermost layer of the eye. It helps to focus light as it enters the eye and also protects the inner structures of the eye. The cornea is made up of five different layers of cells, with the outermost layer being the corneal epithelium.

The precorneal tear film, which covers the front of the eye, helps to protect the corneal epithelium. This tear film serves as a protective layer, provides lubrication and nutrition for the cornea, removes debris, has limited bactericidal effects, and aids in maintaining optical clarity.

What is a corneal ulcer in dogs?

When the corneal epithelium is damaged, it can lead to a corneal ulcer in dogs. Essentially, a corneal ulcer is a break or defect in the cornea. Corneal ulcers can generally be divided into two categories: simple or complicated. Simple ulcers are typically acute, superficial, and uninfected, while complicated ulcers may take longer to heal.

Corneal ulcers may develop in any dog, regardless of age, breed or sex. However, brachycephalic dogs (pushed in faces) are especially prone to developing complicated ulcers due to several predisposing factors such as lagophthalmos (inability to close the eyelids completely) and abnormalities with blinking and tear film.

What are the causes of a corneal ulcer in dogs?

A corneal ulcer in dogs can develop when any part of normal corneal physiology, structure, or function is disrupted. Most corneal ulcers occur secondary to inadequate corneal protection or excessive epithelial loss. The most common causes of a corneal ulcer in dogs include:

  • Trauma
  • Cornea irritants such as soaps and alcohol
  • Eyelid abnormalities such as entropion or ectopic cilia. Entropion is a condition in which the eyelid is inverted or folded inward, causing the hair on the edge of the eyelid to rub against the cornea. Ectopic cilia refer to eyelashes that grow in an abnormal direction and often irritate or damage corneal tissue.
  • Dry eye (keratoconjunctivitis sicca)
  • Bacterial and viral infections
  • Glaucoma
  • Eyelid masses or tumours
  • Breed predispositions, especially in brachycephalic, boxers and corgis.

What are the key symptoms you would notice if your dog has a cornea ulcer?

Typical ocular symptoms of a corneal ulcer in dogs include:

  • Excessive tearing
  • Squinting or blinking excessively
  • Ocular redness (congestion)
  • Pawing at the eye
  • Cloudy cornea
  • Sensitivity to light (photophobia)

As a corneal ulcer is very painful for dogs, you may also notice symptoms of lethargy, lack of appetite and general malaise in addition to some of the symptoms listed above.

How does your veterinarian diagnose a corneal ulcer in dogs?

A corneal ulcer is diagnosed by performing a complete ocular examination. This will include a thorough evaluation of the cornea, conjunctiva, and eyelids. Your veterinarian may also perform a fluorescein stain test to better visualize the corneal ulcer. In this test, a fluorescent dye is applied to the cornea and then examined under a special light to highlight any breaks or defects in the corneal epithelium.

In attempts to obtain the cause of the corneal ulcer your veterinarian will also perform other ocular tests such as tonometry to measure the intraocular pressures which are helpful to assess the possibility of glaucoma, a Schirmer tear test to measure tear production that will rule out dry-eye or KCS (keratoconjunctivitis) as well as corneal cytology or cornea culture if a bacterial infection is suspected.

In addition, your veterinarian should also perform a detailed neurological examination as defects in the 5th cranial nerve (Trigeminal nerve, CN V) or corneal sensation can predispose a dog to corneal ulceration. Also, since the 7th cranial nerve (Facial nerve, CN VII) innervates the movement of the eyelids, any lesions involving this nerve can result in corneal exposure and subsequent ulceration.

What are the treatment options for a corneal ulcer in dogs?

The treatment for a corneal ulcer depends on the severity of the condition and the underlying cause. In general, uncomplicated, superficial corneal ulcers may be managed with topical antibiotic therapy, lubricant eye drops and/or ointment.

However, complicated and deep corneal ulcers may require surgical debridement of the necrotic cornea as well as bactericidal and fungal antibacterial antibiotics for treatment. Additionally, conditions such as dry-eye (keratoconjunctivitis sicca), corneal dystrophies, and corneal neoplasia may require long-term medical or surgical management.

It is very important that to be successful in the management of a corneal ulcer in dogs, the underlying cause is addressed. Failure to do so will create frustration for both you and your veterinarian. For example, if an ectopic cilia or ingrown eyelash is causing the corneal ulcer, this needs to be corrected to prevent any future recurrences of the corneal ulcer.

corneal ulcer in dogs treatment drops

What is the prognosis for a corneal ulcer in dogs?

The severity of the ulcer and any other possible eye conditions will determine how successful the healing process will be.

For simple, uncomplicated ulcers, the prognosis is excellent with the appropriate therapy which usually includes topical antibiotics.

Complicated corneal ulcers need to be monitored closely. The prognosis is difficult to predict, depending on the severity of the condition, the dog's response to therapy, the disease's underlying cause, and any secondary changes in ocular structure.

For dogs prone to indolent ulcers such as boxer dogs, when diamond burr debridement or keratotomy is performed, the majority of these ulcers heal with a single procedure in two weeks. These types of procedures are typically performed by a veterinary ophthalmologist.

What is a melting ulcer and how is it treated in dogs?

A melting ulcer is a corneal ulcer that is poorly responsive to standard therapy and often rapidly deteriorates. Melting ulcers are caused by aggressive bacteria, certain types of fungi, or certain types of viruses. The cornea becomes very thin and weak, which can cause the cornea to rupture.

Treatment for a melting ulcer requires aggressive medical and sometimes surgical therapy. The goal of treatment is to stop the ulcer from progressing and to prevent corneal rupture. Treatment typically includes topical antibiotics, antifungals, or antivirals. In some cases, oral antibiotics, antifungals, or antivirals may be necessary. Surgery may also be necessary to repair a corneal rupture.

Can a corneal ulcer cause blindness in dogs?

Corneal ulcers can cause blindness if left untreated. Corneal ulcers can cause the cornea to rupture which can lead to severe pain, infection, and ultimately blindness. Early diagnosis and treatment are essential to prevent further damage and restore your dog's vision.

What are the risk factors for corneal ulcers in dogs?

There are several risk factors for corneal ulcers in dogs. These include:
-Dry eye
-Trauma
-Glaucoma
-Infections
-Eyelid deformities and dysfunction
-Breed (brachycephalics, boxer dogs, and corgis are susceptible)

The best way to prevent corneal ulcers is to have any underlying eye conditions diagnosed and treated early. Prompt treatment of corneal ulcers is also essential to prevent further damage and restore vision.

How is a corneal ulcer in boxer dogs different?

Indolent corneal ulcers is a chronic epithelial ulcer that does not heal through the normal wound healing process. These are specific to dogs and typically seen in middle-aged-older dogs with studies reporting an average age of 8-9 years.

Corneal debridement and grid keratotomy are required in the treatment of superficial corneal erosions seen in boxers.

Can a corneal ulcer cause blindness in dogs?

Corneal ulcers can cause blindness if left untreated. Corneal ulcers can cause the cornea to rupture which can lead to severe pain, infection, and ultimately blindness. Early diagnosis and treatment are essential to prevent further damage and restore your dog's vision.

What are the complications of a corneal ulcer in dogs?

Corneal ulcers can lead to several complications in dogs including:
-Corneal rupture
-Severe pain
-Infection
-Blindness

Early diagnosis and treatment are essential to prevent further damage and restore your dog's vision.

What are the signs the dog ulcer is healing?

For rapid healing to occur, there needs to be a blood supply. As the cornea does not contain any blood vessels, neovascularization will occur to facilitate healing. This is when new blood vessels grow from the limbus (the edge of the cornea where it meets the white part of the eye) into the cornea.

The neovascularization process is normally complete within 3-4 days, at which time you will see a significant reduction in corneal opacity and staining. However, it can take several weeks to months for the cornea to heal completely. Other signs that the ulcer is healing include a decrease in pain, decreased tearing or squinting, and an overall improvement in your dog's symptoms.


In summary, a corneal ulcer is a painful and potentially sight-threatening condition that can affect dogs of any age, breed or gender. The most common symptoms of a corneal ulcer include squinting, excessive tearing, prolapsed third eyelid, pawing at the eye and ocular redness. There are many causes of a corneal ulcer in dogs and can include dry eye, trauma, glaucoma, infections, eyelid deformities and dysfunction. Specific therapy depends upon the type and severity of the ulcer. corneal ulcers can be treated with topical antibiotics, lubricant eye drops and/or ointment however; more severe corneal ulcers may require surgical debridement or keratotomy. To be successful in the management of corneal ulcers, the underlying cause must be addressed. Failure to do so will create frustration for both you and your dog. Prompt diagnosis and treatment are key to preventing further damage and restoring your dog's vision. With the appropriate diagnosis and care, corneal ulcers in dogs typically have a good prognosis for healing.