Corneal Ulceration in Dogs

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

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:

Treatment of Dogs with Corneal Ulcerations

Treatments for corneal ulceration may include any of the following:

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.

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:

Diagnosis In-depth

Your veterinarian will do a complete medical history and perform a thorough ophthalmic examination. Thorough examination provides essential information regarding the cause, duration, and severity of the corneal ulcer. It may also highlight other related symptoms or diseases such as those listed above. Parts of the examination are often conducted in a darkened room using a bright light source and some form of magnification.
As part of the examination, fluorescein stain is applied to the cornea and any excess is rinsed off. Fluorescein stain adheres to any areas where the surface layer of the cornea is missing. It outlines the ulcer and permits accurate assessment of the size and depth of the ulcer.If low tear production is suspected as the cause, a Schirmer tear test is performed. A small strip of calibrated filter paper is placed inside the lower eyelid and left in place for one minute. The distance to which tears flow along this filter paper is a measure of the volume of tears produced. .Your veterinarian may assess your dog’s blink reflex. This involves a gentle tap with the finger at the corners of the eye and observation of the completeness and speed of eyelid closure. Be sure to tell your veterinarian if you have seen your dog sleeping with his eyelids partly open, thus potentially exposing the middle of the cornea to drying.In cases where the ulcer appears infected, special samples may be collected from the cornea for examination under a microscope, for bacterial culture, and for antibiotic sensitivity testing. This is particularly important if an ulcer has progressed rapidly or has failed to respond to appropriate antibiotics.If special techniques, equipment, and/or training are required, your veterinarian may refer your dog to a veterinary ophthalmologist for further evaluation.

Treatment In-depth for Dogs with Corneal Ulcerations

The principal goals in the treatment of corneal ulceration are to identify and treat its cause, to prevent secondary infection, and to encourage healing. Following removal of the inciting cause and appropriate treatment, repair of minor corneal ulcers is often complete within seven days. Patients with slow-healing or rapidly progressive ulcers require more protracted therapy.

The typical therapeutic approach to ulcers may include any of the following:

Follow-up Care for Dogs with Corneal Ulcerations

Follow-up care of corneal ulcers is critical. Administer any prescribed medication(s) as directed and be certain to alert your veterinarian if you are experiencing problems treating your dog. Optimal follow-up veterinary care often involves the following: