Did you know your dog has a third eyelid? It’s not always obvious, but this little flap of tissue plays a big role in keeping your dog’s eyes healthy and protected.
If your dog’s third eyelid is suddenly visible, especially if it’s sticking out all the time, that can be a sign of an underlying health problem. Many people are familiar with “cherry eye,” where the gland in the third eyelid prolapses, but that’s not the only reason the third eyelid in dogs might become noticeable.
This article will cover everything you need to know about your dog’s third eyelid, what problems can arise, and what you should do if you notice something’s not quite right.
Understanding the Third Eyelid: Anatomy and Function
All dogs have a third eyelid, also known as a nictitating membrane. It’s a fold of protective tissue in the inner corner of the eye.
In most cases, you won’t see much of your dog’s third eyelid unless they’re sleeping or need extra protection for their eye. Humans actually have a vestigial third eyelid too, though it’s been reduced to a tiny fold in the corner of our eyes.
So what does this extra eyelid do?
The third eyelid protects the cornea from injury by sweeping across the eye to remove debris and spread the tear film. It’s kind of like a windshield wiper for the eye.
The gland of the third eyelid is also responsible for producing a significant portion of the tear film, responsible for up to 60% of it! This tear film is critical for preventing dry eye and keeping your dog’s eyes healthy and comfortable.
Cherry eye: Third eyelid gland prolapse
What is cherry eye?
Cherry eye is the term for prolapse, or displacement, of the third eyelid gland. If your dog has cherry eye, the gland in their third eyelid will pop out of its normal position and become visible as a red, swollen mass in the corner of their eye.
Cherry eye is believed to be caused by a weakness in the tissues that hold the gland in place. The weakness may be due to a genetic predisposition.
Why is cherry eye a problem?
When the gland prolapses, it interrupts normal tear production, which can lead to dry eye. Decreased tear production can be uncomfortable for your dog and may even damage their cornea.
Also, an exposed gland is more vulnerable to bacteria and other irritants, which means it’s more likely to become inflamed or infected.
Which breeds are prone to cherry eye?
Some breeds are more prone to cherry eye than others. These include Bulldogs, Shih Tzus, Lhasa Apsos, Cocker Spaniels, Great Danes, and Mastiffs. Brachycephalic breeds (short-nosed dogs) are more likely to develop cherry eye than other dogs; one study found that short-nosed dogs are 6.9 times more likely to develop cherry eye.
Other Reasons You Might See That Third Eyelid
Cherry eye isn’t the only reason your dog’s third eyelid might be more visible than usual. Here are some other potential causes:
Horner’s syndrome
Horner’s syndrome is caused by nerve damage that affects the muscles in your dog’s eye and face. One of the signs of Horner’s syndrome is elevation of the third eyelid.
Dehydration
Dehydration can sometimes cause the third eyelid to become more visible.
Make sure your dog always has plenty of fresh water, particularly in hot weather.
Other eye conditions
Irritation, infection, or inflammation (conjunctivitis) can cause the third eyelid to become more prominent. Corneal ulcers or a foreign body in the eye can also cause the third eyelid to rise up.
If you’re concerned about your dog’s eye health, it’s always a good idea to consult with your veterinarian.
Symptoms and diagnosis
The main thing you’ll notice if your dog has a cherry eye is a red or pink bulge in the corner of their eye. You might also see them tearing up more than usual, have some discharge from their eye, or squint a lot.
To figure out what’s going on, your veterinarian will do a physical exam. They’ll look at your dog’s eye and the stuff around it to see what’s making the third eyelid so obvious. They might also run some other tests, like checking how much tear production there is, to make sure it’s not something else going on.
Treatment Options for Cherry Eye
If your dog has cherry eye, the best course of action is generally surgical correction. It’s important to note that vets don’t recommend removing the gland, since that can lead to dry eye later in life.
Surgical Correction
The “pocket technique,” also known as the Morgan pocket technique, is a popular and successful surgical approach. In this procedure, the surgeon creates a pocket in the conjunctiva and tucks the prolapsed gland back into its proper position.
Post-Operative Care
After surgery, your vet will likely prescribe antibiotics, pain medication, and eye drops or ointments to help with healing. It’s important to restrict your dog’s activity during the recovery period to allow the surgical site to heal properly. Be sure to follow your veterinarian’s instructions carefully, and don’t be surprised if your dog needs to wear a cone to prevent them from rubbing or scratching at the eye.
Potential Complications
It’s possible for the gland to prolapse again, especially in certain breeds or if a previous surgery has failed. But with an experienced surgeon, the pocket technique has a success rate of around 90%.
Preventing Cherry Eye
There’s no foolproof way to keep cherry eye from happening, especially in dogs that are genetically predisposed. But there are a few things you can do.
- Regular vet visits are key, particularly if you have a breed that’s prone to this condition. Spotting it early makes a big difference.
- If your dog is prone to cherry eye, switch from a collar to a harness. This can help keep pressure off their neck and face.
Key Takeaways
The third eyelid plays a vital role in keeping your dog’s eyes healthy. If you notice that third eyelid is visible more than usual, schedule an appointment with your veterinarian to find out the cause and start treatment.
Prompt intervention is especially important in the case of cherry eye. Early treatment can help preserve tear production and prevent other complications.