What is Eye Ulcer in Dogs?
Eye ulcers in dogs, also known as corneal ulcers or ulcerative keratitis, occur when the outer layer of the eye, called the cornea, erodes, resulting in a dent or divot. These ulcers can be either superficial, affecting only the surface of the cornea, or they can penetrate deeper layers of the eye. Symptoms of eye ulcers in dogs include pain, redness, discharge from the eye, frequent blinking or keeping the eye closed, and sometimes swelling. While this condition is commonly diagnosed in brachycephalic (flat-nosed) dog breeds, it can affect dogs of any breed.
Symptoms
Symptoms of eye ulcers in dogs vary in intensity, depending on the cause and the extent of the erosion. These symptoms can include:
- Increased blinking
- Excessive tearing
- Redness in the eye
- Swelling of the eyelid or the surrounding skin
- Scratching or rubbing the eye against surfaces
- Elevated third eyelid (located in the inner corner of the eye)
- Keeping the eye tightly shut
- Discharge from the eye, which may be yellow, green, or bloody in severe cases
- Perforation or rupture of the outer layer of the eye in severe instances
- Blindness in the affected eye in severe cases
- Decreased appetite
- Lethargy or withdrawal behavior
Causes
Eye ulcers in dogs can arise from any disruption to the normal structure, function, or physiology of the outer layer of the eye, known as the cornea. Common causes of eye ulcers in dogs include trauma, foreign body injury, or chemical burns.
Various factors can contribute to ulcerative keratitis in dogs, including:
- Trauma: such as scratches from other animals, collisions with tree branches or vegetation, or self-inflicted injury from excessive rubbing of the face.
- Foreign bodies: particles like sand, dirt, or other foreign materials can enter the eye and become trapped behind the eyelids, causing repeated damage to the cornea.
- Chemical irritation or burns: exposure to substances like shampoos, topical medications, or household cleaning products that enter the eye.
- Bacterial infections.
- Viral infections.
- Secondary issues related to eye structure or congenital abnormalities: such as abnormal eyelash growth (distichia), eyelid masses or tumors, or entropion (inward rolling of the lower eyelid).
- Secondary complications from chronic dry eye, also known as keratoconjunctivitis sicca.
- Neurological conditions that impair normal blinking.
- Certain endocrine disorders like diabetes mellitus, Cushing’s disease, and hypothyroidism.
- Inherited conditions, such as epithelial dystrophy, which is more common in breeds like Boxers, King Charles Cavaliers, Beagles, Cocker Spaniels, Afghan Hounds, and Alaskan Malamutes.
Diagnosis
To diagnose eye ulcers in dogs, veterinarians conduct various eye tests to determine the cause and appropriate treatment plan. The diagnosis aims to distinguish between simple and complicated ulcers.
A simple ulcer involves only the superficial layer of the cornea and typically heals within 7-10 days without penetrating deeper layers. Complicated ulcers extend into deeper corneal layers, risking infection and severe inflammation.
Complicated ulcers come in three types:
- Persistent corneal ulcers: These involve superficial ulcers with an elevated outer rim, requiring longer therapy or surgery if they worsen.
- Corneal foreign bodies: Objects can penetrate superficially or deeply, causing intense inflammation. Removal by a veterinarian and aggressive therapy are often necessary, with surgery sometimes required.
- Stromal ulcers: Affecting the deepest corneal layer, these ulcers are often infected, inflamed, and painful, requiring aggressive medical and surgical management.
Veterinarians examine the eye for foreign objects, lacerations, abnormal eyelashes, or masses before diagnostic testing. Tests may include:
- Fluorescein stain: A dye highlights the ulcerated tissue, aiding diagnosis.
- Schirmer tear testing: Measures tear production to diagnose chronic dry eye.
- Intraocular pressures (tonometry): Assesses pressure behind the eye, crucial for deep or extensive ulcers.
- Bacterial culture: Samples from the cornea incubate to identify bacterial growth, guiding antibiotic therapy.
- Cytology: Assesses corneal cells under a microscope, aiding therapy for chronic or deep ulcers.
Treatment
Treating eye ulcers in dogs varies based on the type and severity of the corneal ulcer. Treatment approaches encompass both medical and surgical interventions.
Medical Therapy for Eye Ulcer in Dogs
Treatment for eye ulcers in dogs typically involves a combination of therapies tailored to the severity and complexity of the condition. Simple ulcers are commonly treated with broad-spectrum topical antibiotics along with topical pain relief medication. In some cases, systemic pain medication may also be administered to ensure the dog’s comfort. Additionally, contact lenses are occasionally used to shield the eye’s outer layer during the healing process, which typically spans 3-7 days with proper therapy.
More complicated ulcers demand intensified treatment protocols, often requiring stronger topical antibiotics administered every 2-4 hours, depending on the diagnosis. Oral antibiotics and pain medications are frequently prescribed for systemic relief and management. Veterinary monitoring is crucial during the treatment period to prevent ulcers from worsening or becoming infected. Deep ulcers, if they develop, may necessitate surgical intervention.
When foreign objects are the cause, superficial ones can be gently irrigated out with a sterile solution, while deeper ones may require removal under general anesthesia by a veterinarian. Following foreign object removal, any remaining lacerations or ulcers are treated with aggressive medical therapy.
Indolent ulcers, which resist healing, often necessitate keratotomy or burr debridement procedures. These techniques involve using specialized instruments to remove dead cells from the ulcer and promote blood vessel growth for healing. Typically, healing occurs within 2-3 weeks following these procedures. Regular follow-up appointments with the veterinarian are essential to monitor the ulcer’s progress and ensure the dog’s eye health.
Surgical Therapy for Eye Ulcer in Dogs
When an eye ulcer in dogs becomes deep, complicated, melting, or chronically unresponsive to medical treatment, surgical intervention becomes necessary. The most common surgical procedure performed in such cases involves conjunctival grafts, where conjunctival tissue is transposed over the affected ulcer to offer support and facilitate healing. In certain instances, for ulcers stemming from congenital or neurologic issues, a third eyelid flap and temporary surgical closure of the eyelids (tarsorrhaphy) may be employed to act as a protective bandage during the healing process.
Chronic or deeper ulcers can lead to secondary inflammation in the eye, known as uveitis, which necessitates more aggressive anti-inflammatory therapy involving systemic non-steroidal anti-inflammatory drugs and additional systemic analgesics.
During the healing phase of all types of eye ulcers, it’s imperative to use Elizabethan collars or pet cones to prevent self-trauma caused by rubbing or pawing and to safeguard the dog during recovery. These collars must remain on until your veterinarian deems it safe for removal. Premature removal can result in trauma and complicate existing corneal ulcerations.
Living and Management
After diagnosis, most simple eye ulcers in dogs are rechecked by a veterinarian within 5-7 days to evaluate healing progress. With appropriate therapy, the majority of these ulcers typically heal within this timeframe, and the prognosis for complete recovery is usually excellent.
Deeper or more complex ulcers require more frequent monitoring, often within 1-2 days of diagnosis, to ensure they are improving and not worsening. In some cases, hospitalization may be necessary for intensive treatments every 2-4 hours. Medications may be adjusted or prolonged based on results from bacterial culture and cytology tests.
For melting, deep stromal, or complicated eye ulcers, referral to a veterinary ophthalmologist is often recommended for specialized treatment and potential surgical intervention. Conjunctival grafts are typically left in place for 2-3 months, and complicated ulcers are closely monitored by a veterinarian for several weeks post-surgery or therapy to assess tear production, which may require temporary or permanent medical management in some instances.
It’s crucial to diagnose and treat any underlying medical conditions or congenital abnormalities to prevent the recurrence of chronic eye ulcers or frequent development of corneal ulcers in the future. Regular veterinary care and follow-up appointments are essential for monitoring and managing the dog’s eye health effectively.
Eye Ulcer in Dogs FAQs
What is the cornea?
The cornea is the transparent outer layer of the eye composed of three cell layers. These layers include the epithelium, the stroma (the thick middle layer), and the endothelium, also known as Descemet’s membrane.
Can a corneal abrasion progress to become a corneal ulcer?
Yes, a corneal abrasion occurs when the outer layer of the eye, the corneal epithelium, is eroded. If the erosion extends deeper, affecting the middle or inner layers of the eye, it becomes a corneal ulcer. This progression often results from self-trauma, bacterial infection, or chronic inflammation.
What is an indolent corneal ulcer?
Indolent corneal ulcers are superficial ulcers that fail to heal within 7 days. Despite initial improvement with therapy, these ulcers deteriorate without an obvious cause. Treatment often involves keratectomy, a type of laser eye surgery, to remove unhealthy layers and facilitate healing.