Dogs have six eyelids — three on each eye. This simple fact of canine anatomy is something most dog owners know nothing about, until a condition known as cherry eye causes something to go wrong with one of their pet's third eyelids.
Cherry eye occurs when there is a pink or red mass protruding from under a dog's third eyelid. More formally known as eyelid protrusion or a prolapse of the gland of the nictitating membrane, cherry eye usually isn't a cause for major concern. However, quick treatment is necessary to ensure that your furry friend doesn't suffer any long-term ill effects.
Signs and Symptoms of Cherry Eye
Under normal circumstances, your dog's third eyelids are hidden from view. It's a case of out of sight, out of mind for most dog owners, but that all changes pretty quickly when one of those eyelids is no longer concealed.
Of course, it's usually pretty easy to determine when your dog is suffering from Cherry Eye which, handily for panicked dog owners, looks very much like its name suggests.
The most obvious sign to look for is a protruding red or pink mass in the corner of your dog's eye. This oval-shaped mass can appear in one or both eyes, and if your dog gets it in one eye then they're more prone to suffer from it in the other eye at a later date.
Aside from the telltale fleshy protrusion, you may also notice accompanying swelling and irritation. Dogs may squint due to the resulting pain, and the affected eye may also be dry and red. Some dogs will paw at their face in an effort to relieve their discomfort or rub their face along the grass or floor to overcome the irritation.
Serious cases can also lead to eye infections and vision loss if left untreated, not to mention a number of other long-term side effects, so make sure you get cases of cherry eye seen to by your vet as soon as possible.
The Science of Cherry Eye
To better understand cherry eye, we first need to take a closer look at the anatomy of a dog's eye. While you're probably well aware that dogs have upper and lower eyelids that function much the same way as our own eyelids do, you may not know where the third eyelids fit into the picture.
Also known as nictating membranes, third eyelids are based underneath the lower eyelid and basically provide an extra layer of protection for the eyes. Think of the third eyelid as being like a windscreen wiper for doggy eyes — it sweeps dirt and other debris off the surface of the eyes.
It also has its own dedicated tear gland and has the crucial role of keeping the eyes moist. In fact, the third eyelid produces anywhere between 35 and 50 percent of the moisture in the eye, making it an essential contributor to general eye health.
Cherry eye occurs when the connective tissue holding the tear gland in position is too weak, faulty or sustains damage in some other way. If the attachment breaks down, the gland can slip free from its usual place and appear from behind the third eyelid. This is when you'll notice that distinctive fleshy mass making an appearance in your dog's previously pristine eye.
Dogs of all shapes and sizes can potentially develop cherry eye, but the condition is most common in breeds like Beagles, Cocker Spaniels, Boxers, Basset Hounds, Bulldogs (English and French), Pekingese and Boston Terriers. It's thought that cherry eye is most likely caused due to a combination of facial anatomy that includes prominent eyes, and a genetic weakness of the connective tissue that normally holds everything in place.
While it looks quite alarming and can often be painful, cherry eye can usually be successfully treated if caught early.
Diagnosis and Treatment of Cherry Eye
Cherry eye is not a life-threatening emergency, but it is important to get it seen to as soon as possible as it can cause chronic discomfort and long-term complications. It's also relatively simple to diagnose, as that distinctive red mass protruding from the corner of a dog's eye is typically a dead giveaway.
While there's no known way to prevent or at least reduce the risk of cherry eye developing in dogs at risk of the condition, the good news is that it's usually fairly easy to treat. The main goal of treatment is to return the function and appearance of the third eyelid to as normal a state as possible, to preserve tear production from the third eyelid's tear gland, and to reduce the dog's discomfort.
If caught early enough, it's sometimes possible for cherry eye to be corrected by gently massaging the gland back into place. Speak to your vet to find out whether this could be an option.
Topical therapy using antibiotics and anti-inflammatories can also help reduce inflammation and prevent secondary infections, but surgery is the most commonly recommended course of action. This involves the surgical repositioning of the third eyelid's tear gland to ensure that it stays in place. There are several techniques available and your veterinarian will be able to determine the best option for your pet.
When all other options fail, removal of the affected tear gland may be recommended. However, the resulting reduction in tear production can lead to other problems, so this method is only used as a last resort.
By a Labrador Retriever lover Tim Falk
Published: 05/11/2018, edited: 04/06/2020