Dry Eye in Dogs 

Dry eye in dogs, medically known as Keratoconjunctivitis Sicca (KCS), is a common condition where the eyes do not produce enough tears to keep them properly lubricated. Tears are essential for maintaining eye health, as they help protect the eyes by washing away debris, providing nutrients, and preventing infections. When tear production is insufficient, it can lead to discomfort, irritation, and more serious eye problems.

 

What Is Dry Eye Syndrome in Dogs?

Dry Eye Syndrome is a condition in dogs characterized by insufficient tear production. Tears are essential for maintaining the lubrication, comfort, and overall health of a dog’s eyes. They contain antibacterial proteins, mucus, white blood cells, and enzymes that help keep the eyes clear, free of debris, and protected from infections.

A dog's tears are composed of three layers: the lipid (fat) layer, the aqueous (water) layer, and the mucin layer. The lacrimal gland and the gland of the third eyelid are responsible for producing the watery component of tears. In dogs with dry eye syndrome, these glands produce little to no aqueous layer, while the glands responsible for the lipid and mucin layers continue to function. This imbalance typically results in dry, irritated eyes that are often accompanied by thick, mucous-filled discharge.

Without adequate tear production, the eyes become vulnerable to irritation, infections, and potential damage to the cornea, making early diagnosis and treatment crucial to maintaining eye health in affected dogs.

 

What Causes Dry Eye?

Dry eye syndrome in dogs, can result from a variety of underlying conditions. Determining the cause is essential for effective treatment, and your veterinarian will base their diagnosis on your dog’s medical history and a thorough examination. Here are some of the common causes:

Immune System Dysfunction

The majority of dry eye cases in dogs are due to an autoimmune response where the immune system mistakenly attacks and destroys the lacrimal and third eyelid glands responsible for tear production. Unfortunately, the exact reason why this happens is still unknown.

Medications

Certain medications can cause dry eye syndrome as a side effect, often appearing shortly after the dog begins the treatment. In some cases, the condition may be temporary and resolve once the medication is discontinued, but permanent damage is also possible. It’s important to discuss potential side effects with your vet before starting any new medications.

Genetic Factors

Congenital alacrimia, a genetic form of dry eye, is seen in certain breeds like Yorkshire Terriers. This condition typically affects only one eye and is present from birth, highlighting the role of genetics in some cases of KCS.

Endocrine Disorders

Systemic diseases such as hypothyroidism, diabetes, and Cushing’s disease can reduce tear production, leading to dry eye syndrome. These endocrine disorders interfere with the body’s ability to regulate various functions, including those necessary for adequate tear production.

Infectious Diseases

Certain infectious diseases, including canine distemper virus, leishmaniasis, and chronic blepharoconjunctivitis, can lead to dry eye by damaging the tear-producing glands or affecting the eyes directly.

Medical Procedures

Surgical removal of the third eyelid gland, often done to correct a condition known as "cherry eye," can result in permanent dry eye if the gland is entirely removed. Similarly, local radiation treatments for tumors near the eyes can damage the lacrimal and third eyelid glands, leading to decreased tear production.

Neurological Problems

Loss of nerve function to the tear glands, often secondary to conditions like inner ear infections, can lead to reduced or halted tear production. This type of dry eye is often associated with other neurological symptoms.

Traumatic Injury

Severe inflammation or injury, such as wounds or trauma from car accidents, can damage the tear glands and result in dry eye syndrome. The damage can be direct or due to secondary complications from the injury.

Transient Causes

Temporary causes of dry eye include anesthesia and certain medications like atropine, which reduce tear production. Typically, normal tear production resumes once these factors are removed.

 

Symptoms of Dry Eye in Dogs 

Dry Eye in dogs presents with several noticeable symptoms that indicate discomfort and potential eye health issues:

• Redness and Inflammation: The eyes may appear red and inflamed, particularly in the conjunctiva (the tissues surrounding the eye).
• Frequent Squinting and Blinking: Dogs with dry eye often squint or blink frequently due to irritation and discomfort.
• Dryness on the Cornea: The cornea, which is the clear, dome-shaped surface of the eye, may appear dry or dull.
• Thick, Mucous-like Discharge: A sticky discharge, often yellow or green if a secondary infection is present, can accumulate on the surface of the eye.
• Eye Irritation and Pain: Dogs may show signs of discomfort, such as pawing at the eyes or rubbing their face on surfaces.
• Corneal Changes: Over time, the cornea may develop irregularities, including increased blood vessel growth (vascularization) and pigmentation as the eye attempts to heal and protect itself.
• Vision Impairment: In severe cases, the lack of tear production can lead to damage to the cornea, resulting in vision impairment or even blindness.

 

When to contact your vet

If you notice any signs of eye discomfort in your dog, such as persistent redness, inflammation, or frequent squinting and blinking, it’s important to contact your veterinarian promptly. These symptoms can indicate serious issues like dry eye or infections that require professional treatment. Additionally, if you observe thick, mucous-like discharge, especially if it’s yellow or green, or if the cornea appears dry, dull, or irregular, these could be signs of underlying eye conditions that need attention.

Signs of eye pain, such as your dog avoiding light, keeping their eyes closed, or reacting sensitively when their eyes are touched, also warrant immediate veterinary care. Any indication of vision impairment, such as your dog bumping into objects or hesitating to move in unfamiliar areas, should be evaluated by a vet as soon as possible.

 

How Veterinarians Diagnose Dry Eye in Dogs 

Veterinarians diagnose dry eye syndrome, or keratoconjunctivitis sicca (KCS), in dogs using the Schirmer Tear Test (STT). This straightforward and painless test involves placing a small strip of special paper under the lower eyelid to measure tear production. The paper absorbs the moisture and tears from the eye for 60 seconds. Afterward, the amount of tear production is measured. Normal tear production is typically more than 15 millimeters per minute, while less than 10 millimeters indicates dry eye syndrome. To ensure accuracy, the vet may repeat the test.

In addition to the STT, veterinarians often perform a fluorescein stain test to check for corneal ulcers. This test involves applying a special dye to the eye, which causes any ulcers to glow bright green under a black light. Additionally, vets may measure intraocular pressure to detect inflammation or glaucoma, conditions that commonly occur alongside dry eye and require simultaneous treatment. These combined diagnostic tools help veterinarians accurately identify and manage dry eye syndrome in dogs.

 

Treatment of Dry  Eye in Dogs 

The specific treatment plan depends on the severity of the condition and the dog’s medical history. Common treatment options include:

Lacrimostimulants

Veterinarians often prescribe medications like cyclosporine or tacrolimus to stimulate tear production. Cyclosporine helps by suppressing the immune system’s attack on the tear-producing glands, allowing them to function normally and produce tears. If cyclosporine is not effective, tacrolimus may be used as an alternative.

Lacrimomimetics (Artificial Tears)

Artificial tears are essential in managing dry eye, especially during the early stages of treatment when natural tear production is still inadequate. These eye lubricants help keep the eye surface moist, improve comfort, and flush out debris and allergens. They are typically used alongside lacrimostimulant medications.

Antibiotics

If the dog has developed a bacterial infection or corneal ulcers due to dry eye, topical antibiotics may be prescribed to treat these issues. In cases where dry eye is related to nerve damage, medications like pilocarpine can be used to stimulate tear production by increasing glandular secretion.

Surgery

For dogs that do not respond to medical treatments, surgery may be an option. A procedure called parotid duct transposition involves redirecting a saliva gland to the eye, allowing saliva to serve as a substitute for tears. This surgery is considered when other treatments fail to provide sufficient relief.

 

Home Remedies for Dogs with Dry Eye

Home remedies can complement veterinary care in managing dry eye in dogs by providing additional comfort and support. Applying warm compresses to your dog’s eyes a few times daily can help soothe irritation and clean away any discharge that accumulates. This simple practice can alleviate some discomfort and promote a healthier eye environment. Using vet-recommended artificial tear drops or gels between prescribed treatments is another effective way to keep your dog’s eyes moist. These products act as lubricants, providing temporary relief from dryness and helping to protect the eyes until natural tear production improves.

Adding omega-3 fatty acids to your dog’s diet can reduce inflammation and support overall eye health. Additionally, maintaining good eye hygiene by gently cleaning your dog’s eyes daily with a warm, wet cloth can prevent debris buildup and reduce the risk of infections. Using a humidifier in your home can also help maintain moisture in the air, which is especially beneficial in dry climates or during winter. While these remedies can offer relief, they should be used alongside the treatments prescribed by your veterinarian. Regular check-ups are essential to ensure that your dog’s dry eye is being managed effectively and to adjust the treatment plan as needed.

 

Preventing Dry Eye in Dogs 

Preventing eye issues in dogs involves regular care and attention to maintain their eye health and reduce the risk of developing conditions like dry eye, infections, or injuries. Here are some key steps you can take:

• Regular Eye Cleaning: Gently clean your dog’s eyes with a vet-approved eye cleaner to remove debris, dust, and discharge. This helps prevent irritation and reduces the risk of infections.

• Routine Check-ups: Regular veterinary check-ups are essential for early detection of potential eye problems. Your vet can spot issues before they become serious and recommend appropriate care.

• Monitor for Symptoms: Be vigilant for signs of eye discomfort, such as redness, squinting, or discharge. Early intervention can prevent minor issues from escalating into more serious conditions.

• Protect the Eyes: If your dog is prone to eye injuries, consider using protective eyewear during activities that might expose them to debris, dust, or potential trauma.

• Keep Hair Trimmed: If your dog has long hair around the eyes, keep it trimmed to prevent it from irritating the eyes or trapping dirt and debris.

• Manage Allergies: If your dog has allergies, work with your veterinarian to manage them effectively. Allergies can lead to chronic eye irritation and increase the risk of infections.

• Provide a Balanced Diet: A healthy diet rich in essential nutrients supports overall health, including eye health. Consider supplements like Omega-3 fatty acids if recommended by your vet.

 

Conclusion

Dry eye in dogs is a manageable condition when detected early and treated appropriately. By understanding the causes, recognizing the symptoms, and following your veterinarian’s recommended treatment plan, you can help your dog maintain healthy, comfortable eyes and prevent potential vision problems. Regular eye care and monitoring are key to ensuring your dog’s long-term eye health.