What Causes Cherry Eye in Dogs?

If you've noticed a red, swollen mass appearing in the corner of your dog's eye, you may be looking at a condition called cherry eye. Despite its alarming appearance, this common canine eye problem is usually manageable with proper veterinary care. Understanding what causes cherry eye can help you recognise the condition early and seek appropriate treatment for your furry companion.

Understanding Cherry Eye: The Basics

Cherry eye, medically termed prolapse of the nictitans gland or third eyelid prolapse, occurs when the tear-producing gland associated with your dog's third eyelid becomes inflamed and protrudes. The condition gets its name from the distinctive cherry-red appearance of the swollen tissue that becomes visible at the inner corner of the eye. This gland, also known as the Harderian gland, normally sits tucked beneath the third eyelid where it remains invisible.

The Primary Cause: Anatomical Weakness

The main cause of cherry eye is a congenital weakness in the ligament that normally holds the tear gland in place. This weakness is present from birth, though the condition may not become apparent until later in your dog's life. Certain breeds have a genetic predisposition to developing this problem, suggesting that inheritance plays a significant role.

The following breeds are particularly prone to cherry eye:

• Cocker Spaniels
• English Springer Spaniels
• Bulldogs
• Beagles
• Shih Tzus
• Pekingese
• Pugs

Secondary Contributing Factors

Whilst genetic predisposition is the primary cause, several secondary factors can trigger or worsen the condition:

1. Eye trauma or injury: Any damage to the area around the eye can disrupt the supporting ligaments and cause prolapse.
2. Excessive eye rubbing: Dogs that frequently rub their eyes due to allergies, irritation, or other conditions may inadvertently trigger cherry eye.
3. Inflammation or infection: Conjunctivitis or other inflammatory eye conditions can increase pressure within the eye socket.
4. Rapid growth: Young dogs experiencing rapid growth may experience increased tension on the supporting tissues.

Age and Development

Whilst cherry eye can appear in dogs of any age, it most commonly develops in puppies and young dogs under two years old. The condition typically manifests suddenly, though the underlying weakness has been present since birth. Once it occurs in one eye, there's approximately a 50% chance that the condition will develop in the other eye at some point.

When to Seek Veterinary Attention

If you notice any of the following signs, contact your veterinarian promptly:

• A red or pink bulge at the inner corner of the eye
• Excessive tearing or eye discharge
• Your dog repeatedly scratching or pawing at their eye
• Swelling around the affected eye
• Squinting or apparent discomfort

Key Takeaways

Cherry eye in dogs results primarily from a congenital weakness in the ligament supporting the tear-producing gland, with certain breeds being genetically predisposed to the condition. Whilst the underlying cause cannot be prevented, early recognition and prompt veterinary treatment are essential to prevent complications such as dry eye syndrome. If your dog shows signs of cherry eye, consult your veterinarian who can assess the severity and recommend appropriate treatment options, which may range from conservative management to surgical correction. Understanding this condition empowers you to protect your dog's eye health and maintain their quality of life.