What Are Corneal Ulcers in Dogs?

Introduction

For as long as she could remember, Sarah and her faithful Border Collie, Rex, had been inseparable. Recently, though, she noticed that Rex was constantly rubbing his eye and seemed more sensitive to light than usual. Concerned about her beloved pet’s well-being, Sarah took Rex to the veterinarian for a thorough assessment. After a careful examination, the vet revealed that Rex was suffering from a corneal ulcer, a painful and potentially serious eye condition in dogs.

Corneal ulcer in dogs is a condition that damages the eye’s surface due to trauma or infection. The cornea is the transparent front part of the eye that covers the iris and pupil. It helps us see objects at different distances. This thin layer of tissue is susceptible to any injury. Any injury to this area can lead to loss of vision. A dog’s eyes are vulnerable to infections because they do not have eyelids. Hence, if your pet gets injured, you should immediately take them to the vet.

Corneal ulcers are painful sores on the cornea’s surface (the front layer of the eyeball). They’re usually found at the edge of the eyelid or near the nose. A typical corneal ulcer is an injury to the surface of the cornea. A corneal ulcer usually occurs when the surface of the corneal scarring the tissue due to trauma, infection, chemical burns, or surgery.

What Causes Corneal Ulcers in Canine?

Corneal ulcers can cause a great deal of discomfort in pet patients, accounting for up to 0.80% of conditions diagnosed in primary care practice in the UK. This painful condition occurs when the cornea inflamed, causing irritation and swelling.

Trauma, foreign body injury, or chemical burns are dogs’ most common causes of eye ulcers. Bacterial and viral infections, conformation/congenital issues of the eye, chronic dry eye, and neurologic issues can also lead to ulcerative keratitis.

Physical trauma occurs when a foreign object enters the eye and scrapes or cuts the tissue. This type of wound is often quite painful for a dog and requires immediate medical attention to prevent further injury. In addition, viruses such as Herpesvirus (HV), canine adenovirus-2 (CAV-2), and canine distemper virus (CDV) can also cause corneal ulcers in dogs by attacking tissues directly within the eye or by causing inflammation of neighboring tissues around the eyes that eventually leads to an ulcer formation.

Allergens like pollen or medication side effects can negatively affect how tears are produced or secreted, leading to dryness in the corner and increasing vulnerability to an infection that spawns an ulcer. Finally, foreign objects left on contact lenses overnight can scratch or poke at the cornea, which sometimes results in an inflammation that becomes serious enough to form an ulcer.

Symptoms of Canine Corneal Ulceration

Corneal ulcers in dogs are an eye disease caused by an injury to the cornea, which results in inflammation and pain. Symptoms of corneal ulcer in dogs may include red or cloudy eyes, excessive tear production, discharge from the eye, pawing at the eyes, squinting, blinking rapidly due to pain or discomfort, and avoidance of bright light. In more severe cases, symptoms may include swelling of the third eyelid and a cloudy ulcer on the cornea.

Eye ulcers are most common in brachycephalic (flat-nosed) dog breeds but can affect any breed. If your pet is showing any signs of eye trouble, such as excessive tearing or squinting, it is essential to schedule an appointment with your veterinarian as soon as possible. Corneal ulcers can cause permanent damage if not addressed immediately.

Diagnosis of Corneal Ulcers in Dogs

A veterinarian should scrutinize your dog’s eyes to determine whether there is any sign of infection or injury. Your vet might use one or more of these tests to help him make this diagnosis:

1. Slit lamp examination involves shining a bright light onto your dog’s eye and examining it under magnification. A veterinarian will look at the surface of the eye, the inside of the eyelid, and the tear duct area. He may also take a fluid sample from the tear duct to test for bacteria.
2. Culture – If an infection is suspected, your vet will swab the affected area and send it to a laboratory for testing. Bacteria that grow on culture plates indicate the presence of an infection.
3. Gram stain – This test looks for certain bacteria in the sample taken from the eye.
4. Cytology – This test examines cells from your dog’s eyes in the sample. It helps identify the kind of cells involved in the inflammation process and its severity.
5. Corneal scraping – In this procedure, a thin piece of cotton gauze is used to scrape away some of the cornea’s outer layers (the epithelium). The scrapings are then examined under a microscope. If bacteria are present, they will be seen on the slide.

What is topical ophthalmic?

Topical ophthalmic is a term used to describe the medical specialty of eye care. It includes diagnosing and treating diseases affecting the eyes, such as glaucoma, cataracts, retinal disorders, corneal cell conditions, dry eye disease, etc. In addition, the practice of ophthalmology involves diagnosing and managing eye problems, including refractive surgery, strabismus (eye misalignment), amblyopia (lazy eye), and other vision impairments. Effects of topical ophthalmic application of 0.5% proparacaine hydrochloride on aerobic bacterial culture results for naturally occurring infected corneal ulcers in dogs.

The practice of ophthalmology requires extensive training and education, typically at least seven years after completing undergraduate studies. First, ophthalmologists must pass examinations administered by the American Board of Medical Specialties before becoming board certified. They then undergo additional residency programs to obtain advanced clinical skills. After passing these exams, ophthalmologists can take the National Boards Examination, which consists of multiple-choice tests covering basic science, clinical medicine, surgical procedures, and pathology. Once passed, ophthalmologists can apply for Fellowship in their subspecialty field. This process usually takes another two to three years.

Ophthalmologists treat animal patients who suffer from eye problems, whether due to injury, illness, congenital disability, or aging. Some common eye problems treated by ophthalmologists include:

• Glaucoma – A condition where fluid builds up inside the eyeball, causing damage to the optic nerve.
• Cataract – An opacity of the eye’s lens that causes blurred vision.
• Retina – The light-sensitive tissue lining the back of the eye.
• Strabismus – Misaligned eyes.
• Amblyopia – Lazy Eye – Causes loss of vision when one eye is covered during development.
• Dry Eye Disease – Causes irritation and inflammation of the eye’s surface.

Treatment of Corneal Ulcers in Dogs

If your dog has corneal ulcers, your vet will prescribe medications to treat the problem. There are several treatments available for canine corneal ulcers. Treatment depends on how long the ulcer has been present, its severity, and other factors. This treatment has a 60-70% success rate per procedure and can be repeated every 2-3 weeks until healed.

• Antibiotics

Antibiotic treatment may be necessary if an animal has a bacterial corneal ulcer. Bacterial infections tend to recur unless appropriately treated. A topical antibiotic ointment is applied directly to the affected area. This medication must be changed frequently because it can irritate the eye.

• Steroid Drops

Cortisone drops are often prescribed to reduce inflammation and swelling around the eye. They work best when administered topically every two hours.

• Pain Medication

Pain medications are sometimes needed to control pain associated with corneal ulcers that have not responded to antibiotics. Topical analgesics such as lidocaine gel or cream are commonly used.

• Surgical Removal

Surgical removal of the damaged portion of the cornea is another option. This surgery is performed using a technique called amniotomy.

• Oral medication

This involves giving your dog tablets orally.

• Laser therapy

This involves burning away the diseased tissue using laser beams.

• Eye Patching

This method is used to protect the eye from further damage. In addition, an eye patch is placed over the eye to keep dirt out and prevent drying.

• Artificial Tears

Artificial tears are also used to relieve irritation caused by dry eye syndrome. These products contain special chemicals designed to lubricate the eye.

• Lubricating Ointments

Lubricating ointments soften the eye’s surface, so the eye does not stick together.

• Glaucoma Medications

Eye drops are prescribed to lower elevated intraocular pressure (IOP). Glaucoma medications are classified according to their mechanism of action. For example, beta-blockers reduce aqueous humor production, which lowers IOP.

Carbonic anhydrase inhibitors decrease the production of bicarbonate ions, reducing fluid secretion into the eye. Prostaglandin analogs increase uveoscleral outflow. Alpha agonists dilate blood vessels supplying the ciliary body, increasing the flow of aqueous humor through the trabecular meshwork. Combination therapy includes two or more classes of medication.

How to Treat Corneal Ulcers in Pets?

Treatment for an ulcerated cornea aims to remove the corneal epithelium’s loose surface and promote new epithelial growth to attach to the underlying stroma. These procedures have an 85-95 percent success rate. In addition, topical antibiotics may be used to treat any associated bacterial infection. Local anesthesia is applied to the affected area before surgery. Sedation may also be needed if the animal is anxious.

• Grid or Punctate Keratotomy (GK) is a surgical procedure to correct myopia. It involves making incisions into the cornea regularly to reshape its curvature. The process was first described in 1891 by Dr. Charles Lattes.

The main goal of GK is to flatten the central part of the cornea, which causes light rays to converge toward the retina. This results in less refractive error.

In some cases, the surgery is performed with lasers. In this case, the laser beam makes the incision directly through the corneal tissue.

There are two types of GK:

1. Topical GK – A small incision is made in the cornea’s outer layer. Then, a unique instrument called a microkeratome is inserted into the eye. Next, the surgeon cuts tiny slits along the cornea’s surface.
2. Intrastromal GK – An incision is made inside the cornea’s stroma. Afterward, a unique tool is inserted into the incision. The tool removes a circular piece of the cornea from the center of the incision.

• Diamond burr debridement is a surgical correction procedure that removes dead tissue from under the skin. It is performed to treat chronic ulcer wounds such as diabetic ulcers, pressure sores, venous stasis ulcers, arterial ulcers, decubitus ulcers, and burns. Approximately 75% of SCCEDs heal after the first diamond burr debridement with an appropriate aftercare treatment plan.20 This surgery aims to reduce pain and promote the healing of ulcers.

The procedure involves removing dead tissue from the wound bed and surrounding tissues. This is done by scraping off the damaged tissue and cleaning the area with a sterile gauze pad. A small piece of gauze is cut into a shape that fits the wound and is held firmly against the damage while the surgeon scrapes away the dead tissue. Afterward, the wound is cleaned again with another piece of gauze.

This process is repeated until the entire wound is clean and healthy. If there are any remaining pieces of dead tissue, they are removed during subsequent procedures.

• Superficial keratectomies (SK) remove corneal lesions such as nevus, scars, and vascularized areas. SKs are usually done under local anesthesia. Superficial keratectomy has a 95%+ success rate but requires a general anesthetic. The procedure involves making a small incision at the edge of the lesion and removing the tissue from the inside out. Afterward, the wound is closed with sutures.

The main goal of performing SK is to reduce the size of the lesion so that it no longer interferes with vision. In some cases, SK is used to treat corneal dystrophy.

In most cases, SK is performed when there is a risk of corneal Scarring through the reduction of the lesion if left untreated. It is often recommended before laser surgery because it allows the surgeon to evaluate the depth of the lesion and plan accordingly.

How Can I Prevent My Dog From Developing Corneal Ulcers?

You can do several things to prevent your dog from developing corneal ulcers.

1. Ensure that your dog receives regular veterinary care. Ensure he gets his annual exam, vaccinations, dental cleaning, and parasite control.
2. Avoid exposing him to trauma. Be careful when playing rough games with your dog, especially if he has sensitive eyes. Also, avoid letting him play in the water, snow, sand, mud, or dirt.
3. Cleanse his eyes regularly. Use a warm saline solution to wash away debris and bacteria. Rinse your dog’s eyes thoroughly every morning and night.
4. Provide plenty of fresh air and sunshine. Exposure to sunlight helps stimulate vitamin D production in your dog’s body. Vitamin D plays an essential role in maintaining proper immune system function.
5. Limit your dog’s exposure to smoke and fumes. Smoke irritates the eyes and can damage the cornea. Fumes from household cleaners and gasoline can also harm your dog’s vision.
6. Give your special dog attention. Please pay close attention to his diet and nutrition. Ensure he eats a balanced diet of protein, carbohydrates, vitamins, minerals, and fats.
7. Don’t overfeed your dog. Overfeeding can result in bloat, diarrhea, and vomiting. These problems can further aggravate your dog’s eye condition.
8. Treat your dog’s skin carefully. Dry, cracked skin can become infected and cause serious complications.
9. Consult your veterinarian if your dog develops symptoms of corneal ulcers, including excessive tearing, fever, swollen lymph nodes, or difficulty breathing.

Frequently Asked Questions