What is cherry eye in dogs?
Your dog has a third eyelid (nictating membrane) that keeps the eye moist and protects it from dust. Cherry eye happens when the gland of the third eyelid thickens and prolapses, which means it becomes dislodged from its normal location. Consequently, it protrudes into the inner corner of the eye.
Instead of the typically flat, triangular structure we see in a normal eye, a small, bulbous, pink structure appears in the lower eyelid, which is where the term "cherry eye" comes from.
Cherry eye is distinct from a swollen third eyelid, which can occur due to trauma or conjunctivitis. The cherry eye is typically pink (the color of a dog's mucous membranes) and is distinguished by its bulbous appearance.
This eye condition typically occurs in young, growing dogs under one year old and seldom in adults.
What are other symptoms of cherry eye in dogs?
In addition to the pink, bulbous structure that appears in the lower eyelid, other symptoms of cherry eye include:
- Dry eye
- Pus leaking from the eye
- Swollen eyelid
- A mass that disappears and comes back
What causes cherry eye in dogs?
The answer to this question isn't a simple one, and several factors can contribute to this condition. While we're not sure exactly what causes cherry eye in dogs, we do know that it is a hereditary trait. It's assumed that a variety of genes determine eye and eyelid conformation.
Why are some dog breeds more prone to cherry eye?
Fibrous attachments and connective tissue hold the third eyelid in place. It's also suspected that these fibrous attachments are weaker in some breeds, which makes it easier for the third eyelid gland to prolapse.
Though this eye condition can develop in a dog of any breed, bulldogs, beagles, bloodhounds, Boston terriers, Cane corsos, cocker spaniels, English bulldogs, French bulldogs, Great Danes, Lhasa Apsos, pugs, Shar Peis, shih tzus, and other brachycephalic breeds (short-headed, flat-nosed dogs) are predisposed.
In these breeds, the conformation of the eye, in which the eye's orbit is shallow and the eye protrudes in a "bug-eyed" manner, also seems to factor into the development of this condition.
What environmental factors contribute to cherry eye?
Some dogs may develop cherry eye due to environmental allergies, which cause the third eyelid gland to swell and then prolapse.
What happens if you leave cherry eye left untreated?
While this eye condition may not be painful at first, the eye will become more irritated the longer the condition is left untreated. When the third eyelid gland is moved out of place, blood doesn't properly circulate, which leads to swelling in the gland itself, and potentially infection.
The third eyelid gland produces up to 50% of the watery portion of the tear film. Decreased lubrication due to the exposure of mucous membranes can lead to dry eye, pain, impaired vision, and discomfort. Dry eye requires lifelong medication and is usually irreversible.
Subsequent pawing or rubbing at the eye can lead to further inflammation, bleeding, conjunctivitis, and corneal injury, which can ultimately result in eye damage and vision loss.
A large cherry eye can prevent your dog from being able to completely close their eye, which will lead to prolonged exposure of the cornea and further damage to the eye.
How is cherry eye treated?
Cherry eye in dogs is considered a highly treatable condition. A veterinary ophthalmologist can assess your dog's eye, diagnose the issue, and will typically recommend surgery to carefully place the gland back in its normal position.
The vet may also prescribe an artificial tears ointment to help keep the eye lubricated until surgery can be performed. An anti-inflammatory medication to relieve discomfort and swelling may also be prescribed.
Removal of the gland is only recommended for severe or chronic cases (or extremely rare cases of a tumor), when there may be no other treatment option, especially if function is severely diminished or absent.
What can I expect before, during and after surgery?
Your vet can refer you to our board-certified ophthalmologists at Northwest Animal Eye Specialists. Here is what you can expect before, during, and after the procedure.
Before the Procedure
The veterinary ophthalmologist will provide pre-op instructions. Follow these carefully. A pre-surgical assessment will be conducted and blood tests completed to ensure your dog is in good health, is not displaying any signs of illness such as sneezing, coughing, or diarrhea, and they can undergo anesthesia.
During the Procedure
The veterinary ophthalmologist will make a careful incision into the eyelid margin over the gland, replacing the gland deeper into the orbit, and then suturing the incision closed.
Specific surgical techniques include:
- Tacking - The gland is repositioned and stitched to the connective tissue around the eye to hold it in place.
- Imbrication - Also referred to as an envelope or pocket technique, the veterinary ophthalmologist will remove the tissue above the gland. The gland is then covered with the mucous membrane and stitched closed like a pocket to push the gland back into place.
Depending on the severity of the cherry eye, your veterinary ophthalmologist may combine both of these techniques for the best results.
After the Procedure
Your dog will need to wear an Elizabethan collar to prevent your dog from rubbing or scratching their eye after the procedure. Dogs who still manage to rub their eyes in spite of the collar may need to be crated or hospitalized and sedated so they can heal properly.
You'll also need to administer medication as prescribed by the veterinary ophthalmologist.
While complications of cherry eye surgery are uncommon, there are always potential risks. These include:
- Eye injury and damage
- Swelling
- Inflammation
- Loose stitches that come undone
Some inflammation, swelling, and pain is normal after surgery and should clear up within a week. Contact your veterinary ophthalmologist with any questions or concerns you may have about post-surgical care or your pet's recovery.
What is the prognosis for cherry eye?
In most cases, the gland returns to normal within a few weeks of surgery. Some dogs may experience a re-prolapse of the third eyelid gland and require additional surgery. Many dogs with a prolapse in one eye will eventually experience a prolapse in the opposite eye.
Can cherry eye in dogs be prevented?
You'll likely be able to find a lot of information about cherry eye in dogs online and how to prevent the condition in breeds that are predisposed to it.
While some vets suggest that regularly using artificial tears can keep the gland from growing irritated and therefore prevent it from becoming dislodged, there is no research to suggest this tactic is successful.
The most effective method of prevention requires breeders to consistently spay and neuter all dogs who develop cherry eye, which limits the possibility of this genetic trait appearing in any future offspring.
Note: Northwest Animal Eye Specialists specializes in treating eye conditions and illnesses. The advice provided in this post is intended for informational purposes and does not constitute medical or behavioral advice regarding pets. Please make an appointment with your vet for an accurate diagnosis of your pet's condition.