Corneal Ulceration in Dogs

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Overview of Canine Corneal Ulcerations

Corneal ulceration is a common condition in dogs and is loss of the corneal epithelium (the outermost cells of the cornea) with exposure and possible loss of the underlying corneal collagen. Corneal epithelium is constantly being lost and replaced, and its health and thickness depend on a delicate balance between a dog’s cell loss and regeneration.

Causes of excessive cell loss include injury from ingrown or misplaced eyelashes, exposure to foreign material, chemicals, heat or smoke, infections with certain viruses and bacteria, and from trauma such as cat scratches. Decreased tear production (“dry eye” or keratoconjunctivitis sicca) and inadequate blink responses may cause corneal ulceration. The potential causes of corneal ulcers are almost too numerous to list.

Corneal ulceration can affect any animal; however, those breeds of dogs with more protuberant (prominent) eyes and larger eyelid openings are at increased risk. Some older animals may heal more slowly and, therefore, have ulcers that may be more difficult to treat.

Corneal ulceration is a painful and potentially vision-threatening condition. Early diagnosis and appropriate treatment is usually rapidly curative. Complicated cases can progress to full thickness or perforating ulcers with serious effects on vital structures within the eye.

What to Watch For

  • Squinting
  • Increased tearing
  • Mucus or pus draining from the eye
  • Cloudiness of the cornea
  • Inflamed, red conjunctiva (the normally pink tissue surrounding the cornea and lining the eyelids)
  • Inability to see the eye because the third eyelid is covering it
  • Rubbing at the eye
  • Occasional lethargy
  • Veterinary Care

    Veterinary care includes diagnostic tests and subsequent treatment recommendations.

    Diagnosis of Corneal Ulceration in Dogs

    Diagnostic tests are needed to recognize corneal ulceration, any underlying cause and to exclude other diseases. Tests may include:

  • Thorough ocular examination with special attention to the eyelashes, eyelids and blink reflex, status of the cornea and the interior of the eye
  • Fluorescein staining of the cornea to assess ulcer size, depth and character. Fluorescein is a dye that adheres to the central layer of the cornea and makes the ulcerated area become bright green.
  • Schirmer tear test to measure tear production
  • Cytology, culture and antibiotic sensitivity testing of ocular samples for the presence of infectious agents such as bacteria
  • Treatment of Dogs with Corneal Ulcerations

    Treatments for corneal ulceration may include any of the following:

  • Removal or treatment of the underlying cause
  • An antibiotic eye drop or ointment to treat or prevent infection of the cornea
  • Atropine to dilate the pupil and relieve pain from uveitis (inflammation of the inner layers of the eye) or spasm of the iris
  • An Elizabethan collar to prevent the patient from rubbing the eye and making the ulcer worse
  • Surgery to correct a rapidly progressive or deep corneal ulcer. Surgery may involve applying a soft contact lens or suturing the eyelids partially closed to bandage the eye, or the placement of conjunctival grafts over deep lesions.
  • Oral antibiotics for serious infections of the cornea, and oral anti-inflammatory drugs (such as aspirin) if inflammation is present within the eye
  • Home Care

    At home, administer all veterinary prescribed medications and follow-up with your veterinarian within several days of the original diagnosis. Take care that your dog doesn’t rub at the eye or cause any extra trauma to the healing ulcer. Leave the Elizabethan collar on at all times until your veterinarian approves its removal.

    Observe the eye for signs of worsening, especially cloudiness of the cornea, increased or altered ocular discharge, continued squinting, or more obvious redness of the conjunctiva, which is the white tissue lining in the eyelids and covering the eye).

    Preventive Care

    Examine your dog’s eyes regularly and call your veterinarian if you note any pain or color change. Pay particular attention to your dog’s eyes after he has been running through long grass or brush. If your dog is a hunting or field-trial dog, then examine his eyes after he returns from the field.

    Try not to get anything other than saline or clean water in your dog’s eyes. For example, avoid shampoos, soaps and any other household cleaners. Do not attempt to remove foreign material from your dog’s eye. Instead, seek urgent veterinary care.        

    Related Symptoms or Diseases to Corneal Ulceration in Dogs

    Your veterinarian is usually able to diagnose corneal ulceration with a thorough examination and application of a fluorescein dye to your dog’s cornea. However, discovering the cause of the ulceration and checking for related ocular abnormalities can be challenging. The following conditions may be causes or effects of the corneal ulcer:

  • Eyelash abnormalities. Extra eyelashes (distichia) and/or misdirected eyelashes (ectopic cilia) may cause corneal ulcers, especially in younger purebred dogs. These eyelashes may rub directly on the cornea.
  • Eyelid abnormalities. Rolling in of the eyelid/s (entropion) and/or inability to completely close the eyelids when blinking (lagophthalmos) may cause or exacerbate corneal ulceration. Entropion may be inherited or acquired following injury or inflammation. Entropion causes eyelashes and or hair from the lids to rub across the cornea. Lagophthalmos may develop following injury to the nerves responsible for blinking and is occasionally inherited in dogs with flat faces and protuberant eyes.
  • Keratoconjunctivitis sicca (“dry-eye”). Inadequate production of the watery tears or a deficiency in any of the tear film components can cause the surface of the cornea to become more susceptible to infections and environmental irritation. The tear film is a very important protective mechanism for the eye..
  • Uveitis is seen frequently with more serious ulcers. The pain associated with corneal ulcers causes inflammation within the eye. This inflammation is accompanied by the release of substances within the eye and subsequent uveitis. The uveitis usually resolves once treatment for the ulcer is instituted, but your veterinarian may also recommend specific treatment for the uveitis.
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