Dog Eye Ulcer: Symptoms, Treatment, and Prevention

Is your dog squinting and having drainage from one of their eyes?  

If so, they may be suffering from a corneal ulcer. A corneal ulcer occurs when a dog’s eye gets scratched or poked and can be very painful.  

Let’s explore dog eye ulcers in depth—from symptoms to watch out for to when to bring your pet to the vet. 

What Is an Eye Ulcer (Corneal Ulcer) in Dogs?

A dog eye ulcer—also called a corneal ulcer or ulcerative keratitis in dogs—is a condition where the outer layer of the eye (the cornea) erodes or is damaged, causing a divot or dent.   

This divot can be superficial (on the surface), or it can affect the deeper layers of the eye. 

Eye ulcers lead to pain, redness of the eye, eye discharge, blinking frequently or holding the eye closed, and sometimes swelling. 

Dog eye ulcers are a common condition and are diagnosed most often in brachycephalic (flat-nosed) dog breeds but can easily affect any breed of dog.   

Symptoms of a Dog Eye Ulcer

Symptoms of dog eye ulcers range from mild to severe depending on the cause and severity of the erosion.   

Symptoms in order of severity include:  

• Blinking the eye 

• Excessive tearing  

• Redness of the eye   

• Swelling of the eyelid or skin around the affected eye  

• Pawing at the eye or rubbing their face on the ground  

• Elevated third eyelid (third eyelid is in the inside corner of the eye)  

• Holding the eye completely shut  

• Yellow/green/bloody eye discharge 

• Hole (perforation) in the outer layer of the eye/rupture of the eye 

• Blindness in affected eye 

• Decreased appetite 

• Lethargy or hiding behavior 

What Causes Eye Ulcers in Dogs?

Anything that disrupts any part of the normal outer layer of the eye (cornea) can cause a dog eye ulcer, including if it affects the normal corneal structure, function, or physiology. 

Causes of dog eye ulcers are most commonly trauma, foreign body injury, or chemical burns.    

Let’s look at some of the multiple causes of dog eye ulcers:  

• Trauma. This includes scratches from another animal; running into tree branches, plants or bushes; self-inflicted trauma from rubbing their own face  

• Foreign body. This includes sand, dirt, or other foreign material (like foxtails) that can enter the eye and get stuck behind the eyelids, causing repeated damage to the cornea. 

• Chemical irritation/burns. This can occur from shampoos, topical medications, or household cleaning products getting into the eye. 

• Bacterial infections, like pseudomonas 

• Viral infections, like adenovirus or distemper 

• Secondary to conformation/congenital issues of the eye. Such as abnormal eyelash growth (distichia), eyelid masses or tumors, or entropion 

• Secondary to chronic dry eye. This is called Keratoconjunctivitis Sicca. 

• Secondary to neurologic issues. Some neurologic issues do not allow the eyes to blink appropriately. 

• Secondary to certain endocrine diseases. This includes diabetes mellitus, Cushing’s disease, and hypothyroidism 

• Secondary to inherited conditions. This includes conditions such as epithelial dystrophy, most commonly seen in Boxers, Cavalier King Charles Spaniels, Beagles, Cocker Spaniels, Afghan Hounds, and Alaskan Malamutes 

How Veterinarians Diagnose Eye Ulcer in Dogs

To diagnose a dog eye ulcer, your vet will perform a thorough examination of your dog’s eye to assess for any foreign objects, obvious lacerations or abnormal eyelashes, and masses prior to any diagnostic testing.  

Your vet will then perform some eye tests to find the cause of the ulceration and to decide what the best treatment is for your pup. 

These tests may include: 

• Fluorescein stain. A bright, fluorescent green liquid stain is dropped into the eye and will settles in any ulcers. This makes the ulcer light up under blue light during the ophthalmic exam. 

• Schirmer tear test. This test involves using tiny strips of absorbent paper that wick up the tear film from the eye and test for dry eye. 

• Intraocular pressures (tonometry). For this test the doctor will numb the eye first with a topical anesthesia drop, then a tonopen is used to gently touch the surface of the eye to measure pressure inside the eye. This test screens for uveitis and glaucoma. 

• Bacterial culture. A sterile swab is used to sweep the conjunctival sac near the corner of the eye and sent off to swab a petri dish. If bacteria are present, colonies will grow on the petri dish allowing the vet to diagnosis a bacterial infection. 

• Cytology. Cytology is done by collecting cells from the surface of an eye and looking at them under a microscope. 

Simple vs. Uncomplicated Eye Ulcers 

The most important part of diagnosing and treating eye ulcers in dogs is to figure out if the erosion is simple or complicated: 

• A simple (uncomplicated) eye ulcer only involves the most superficial (surface) layer of the cornea and usually heals within seven to 10 days without progression into the deeper corneal layers.   

• A complicated eye ulcer extends into the deeper layers of the cornea and can become infected or even start “melting” the deeper layers because of severe swelling and microorganism invasion.   

Dog Eye Ulcer Treatment

Treatment of dog eye ulcers depends on the type of corneal ulcer and the severity of the ulcer itself. 

Therapy is divided into two types: medical and surgical therapies.  

Medical Therapy 

Medical therapy is primarily accomplished using topical eye medications. Ofloxacin and neopolybac are commonly prescribed eye antibiotics used to treat simple corneal ulcers. 

Serum therapy may also be recommended if your dog is suffering from an eye ulcer.  

To do this, your vet will collect blood from your dog, allow it to clot in the serum separator tube, spin it down and pull the serum out of the tube. This serum helps slow breakdown of the cornea to allow for speedier healing. It’s important to keep the serum in the refrigerator. 

Atropine eye drops may also be prescribed to help reduce ocular pain. 

Sometimes oral anti-inflammatory pain medication, like carprofen, will be prescribed to help your dog maintain comfort while their eye is healing. 

Surgery 

Complicated eye ulcers, or indolent ulcers, may require surgery to achieve healing. This type of ulcer often has a lip of tissue that needs to be removed for the cornea to heal. 

This surgery is done by removing the excess unhealthy tissue.  The surface is often scored in a grid and then debrided. This helps promote good blood flow and allows for appropriate healing.  

Sometimes a bandage contact lens is applied post-operatively to protect the site. 

Recovery and Management of Eye Ulcer in Dogs

Most simple dog eye ulcers are rechecked by a veterinarian in five to seven days to assess healing. Most of these ulcers heal during this time with the right therapy. 

Prognosis is usually excellent for full recovery.   

Deeper or more complicated ulcers are checked more often, usually one to two days after diagnosis, to make certain that they are showing signs of improvement and not worsening. 

Sometimes, a pet may be hospitalized to perform frequent treatments every two to four hours. Medications are changed or extended based on bacterial culture and cytology results.    

For melting, deep stromal, or complicated eye ulcers, referral to a veterinary ophthalmologist (eye doctor) is usually recommended for treatment and surgical intervention. 

Conjunctival grafts are usually left in place for two to three months. 

Complicated ulcers are monitored closely by a veterinarian for several weeks after surgery or therapy to assess for tear production, which may require medical management for short periods of time or, in some cases, permanently. 

Any underlying medical conditions or congenital abnormalities must be diagnosed and correctly treated to avoid chronic eye ulcers or frequent development of corneal ulcers in the future.  

How To Prevent Corneal Ulcers in Dogs

If your dog is itchy, rubbing, or pawing at the face, consider a recovery collar to keep them from accidentally scratching the eye. 

Avoid letting your dog rough house with cats or other dogs that are likely to bite or scratch their eyes. This is especially true if you have a brachycephalic breed, like a Pug or Boston Terrier, as their eyes are more readily injured. 

Prevent your dog from running through tall weeds where they are likely to sustain an injury to the eye.