Entropion

OVERVIEW: 

 

Entropion is one of the most common genetically inherited visual problems found in domestic dogs.  Entropion is defined as the inversion, or turning inwards, of the eyelids of the dog.  This causes the eyelid to rub up against the cornea, or surface of the eye.  Over time, this rubbing can cause irritation, pain, corneal damage, vision impediment, and even blindness.  The impacts of Entropion are more severe when the eyelid is so inverted that the eyelashes or coat rubs against the cornea, which happens in the majority of Entropion cases.  Entropion varies significantly from case to case.  Entropion can be present in either one or both eyes.  On an individual eye, only the top eyelid may be inverted, only the bottom, or both.  It is, however, considerably more common for the lower eyelid to be inverted than the top.  In many Entropion cases, the entire eyelid is inverted, but in many others only part or parts of it are.  The level of inversion is also quite variable, with some affected eyelids inverting so slightly as to be imperceptible and others being very severely inverted.

 

Entropion can be either hereditary or acquired, although the effects and treatments of the condition are identical regardless of the type.  Hereditary Entropion, also known as developmental, congenital, and primary Entropion, is by far the more common of the two types.  Hereditary Entropion is essentially entirely genetic in nature, and is usually the result of abnormalities in facial structure, especially around the eyes, and/or eyelid support.  Hereditary Entropion usually appears before the dog is one year old, and is often present in puppies as young as a few weeks old.  The exact inheritance mechanism is not yet fully understood, and many researchers have come to the conclusion that it is a polygenic condition, meaning that is caused by abnormalities in a number of different, and often unrelated, genes.  There does seem to be a genetic relationship to Entropion and facial skin folds/wrinkles, flat faces, and shortened muzzles.

 

Acquired Entropion is much less common than hereditary Entropion.  Also known as secondary Entropion, acquired Entropion develops over the course of a dog’s life as a result of various factors which are not necessarily genetic in nature.  Several other medical conditions may result in Entropion, including blepharospasms (eyelid spasms), loss of tone of the orbicularis oculi muscle, chronic inflammation, and a number of facial and eye infections.  Acquired Entropion may also be caused by trauma or injury, obesity, and marked weight loss.  Acquired Entropion may also result from the natural aging process, often as a secondary complication of muscle and skin laxity.  Acquired Entropion can appear in dogs of any age, especially if it is caused by disease or injury, but it significantly more common in older dogs.

 

RISK FACTORS: 

 

The following factors have either been shown to or are widely believed to increase a dog’s chances of developing Entropion:

 

Genetics – Genetics is the single factor that is most responsible for determining whether or not a dog acquires Entropion.  Because Entropion is usually a hereditary condition, a dog whose direct ancestors suffered from Entropion is considerably more likely to develop it.

 

Breed – Certain breeds are at much greater risk of developing Entropion than others, and Entropion is one of the leading health concerns for a number of breeds.  Among those breeds most likely to suffer from Entropion are the Chow Chow, Chinese Shar Pei, Bloodhound, English Bulldog, Akita, Great Dane, English Mastiff, Neapolitan Mastiff, American Staffordshire Terrier, Vizla, Weimaraner, Rottweiler, most Spaniel breeds, and a significant number of others.

 

Wrinkled Skin – Dogs with heavily wrinkled skin, especially if it forms folds on the face, are significantly more likely to develop Entropion than other breeds.  Not only are heavily wrinkled dogs significantly more likely to develop Entropion, but they are also more likely to develop more severe cases and to develop them at a younger age.

 

Facial Structure – Dogs with certain facial features are considerably more likely to develop Entropion than other breeds.  The most commonly associated features are flat faces and shortened muzzles.

 

Size – Although Entropion is common in dogs of all sizes, giant breeds (those weighing over 100 pounds) are considerably more likely to develop the condition than smaller dogs.  Many giant breeds actually suffer from Entropion and ectropion on the same eyelid at the same time.  In such cases the central part of the eyelid is ectropic and the corners are entropic.

 

Age – Hereditary Entropion almost always first appears in dogs less than 1 year old, even in puppies as young as two weeks.  Acquired Entropion can impact dogs of any age, especially if it is caused by infection or injury, but is significantly more common in older dogs.

 

SIGNS & SYMPTOMS: 

 

Entropion is one of the few conditions whose primary symptoms are almost all external.  On a basic level, the eyelids of most dogs suffering from this condition are clearly visibly inverted. 

Canine Entropion

As the eyelids rub up against the cornea, they produce a number of other symptoms.  Probably the most common is redness in and around the dog’s eyes.  Dogs suffering from Entropion often have watery or constantly teary eyes.  The eyes often release ocular discharge which may be thick or gummy and often contains blood and/or pus.  Other eye related symptoms include squinting, frequent blinking, eyelid twitching/blepharospasms, thick, thick heavy skin around the eyes, and difficulty or reluctance to open the eyes, especially in direct sunlight.  Because Entropion can be quite painful, affected dogs often begin to exhibit behavioral changes.  One of the most common and first to develop of these is eye rubbing.  Dogs with Entropion often rub their eyes with increasing frequency as the condition progresses, sometimes becoming so severe that it rises to the level of self-mutilation.  As the dog experiences more pain, it may become lethargic, depressed, or aggressive.  As the condition worsens, it often causes increasingly severe damage to the cornea, leading to corneal scratches, corneal ulceration, corneal erosion, and even potentially corneal rupture.  As time progresses, the dog may experience increasing difficulty seeing and potentially even total blindness.

 

DIAGNOSIS & TESTS: 

 

Entropion is among the easiest canine eye conditions to diagnose.  In most cases, a veterinarian only needs to conduct a visual examination of the eye to look for eyelid inversion.  Veterinarians will, however, conduct a full ophthalmic evaluation to conclusively show that Entropion is the problem and also to determine whether Entropion is the sole problem or whether other conditions are working in tandem with it.  A full ophthalmic examination usually includes a Shirmer tear test, application of fluorescein dye, evaluation of intraocular pressures, and a very thorough checking of all external parts of the dog’s eyes.  Most Veterinarians will also use anesthetic eye drops to ensure that Entropion is the problem rather than blepharospasms.  Anesthetic drops relieve a dog’s eye pain.  If the dog’s eyelids return to a normal state after their application, the dog is probably suffering from blepharospasms.  If the eyelids do not return to a non-inverted state, the dog has Entropion.  Most veterinarians will also conduct additional tests to determine whether any corneal damage has occurred and if so to what extent.  While most veterinarians will be able to easily diagnose Entropion, many will recommend patients to a veterinary eye specialist for additional tests.

 

CONVENTIONAL TREATMENT & MANAGEMENT: 

 

The treatment of Entropion is largely determined by the type of Entropion and the age of the dog, but surgery is usually the end result.  While there are many treatments that can relieve entropion’s symptoms or temporarily relieve it, the vast majority of Entropion cases require surgery to resolve them.  In cases of hereditary Entropion, it is usually recommended that any surgery be delayed until the dog is an adult because the dog’s facial structure changes so much as it grows.  Until the surgery can be performed, eye drops, antibiotics, ointments, and a number of topical treatments are often prescribed.  These treatments are designed to reduce the dog’s pain and discomfort and to prevent further damage due to eye rubbing and self mutilation.  In severe cases, veterinarians often perform an eyelid tacking procedure.  The procedure involves using stitches to tack the eyelids back into an uninverted position.  As the dog grows, this tacking procedure may have to be repeated multiple times, especially in the case of heavily wrinkled breeds such as Chow Chows and Shar Peis.  In some dogs with mild cases of Entropion, this tacking may be enough, and the animal will not have to undergo surgery when it reaches adulthood.  However, the sizable majority of cases will still require surgery.  In this surgery, the eyelids are physically reshaped so that they are no longer inverted.  While in most cases a single surgery is sufficient, many dogs require multiple surgeries to correct this problem.  Veterinarians greatly prefer to be cautious and conservative with Entropion surgeries because if they overcorrect, the dog may develop ectropion, which is where the eyelids grow outwards and do no protect the eyes sufficiently.

 

In cases of acquired Entropion, the treatment is often slightly different.  When the Entropion is caused by a different medical condition such as an injury or infection, the Entropion will often be resolved when the other medical condition is cured or fixed.  A similar regimen of topical treatments is often prescribed until the dog makes a full recovery, and the same tacking procedure will be used for severe cases.  If the Entropion does not clear up after the underlying medical condition disappears or if it developed as a result of other problems, surgery is still necessary.  Cases of acquired Entropion are less likely to require multiple surgeries than hereditary Entropion, but may still do so.  When Entropion appears in very old dogs as a result of the aging process, it may be decided that the potential risk of surgery outweighs any potential benefits to the dog.  In such cases, the topical treatment regimen and sometimes the tacking procedure will be used instead.

 

The success rate from Entropion surgeries is very high, and owners who complete all of the necessary surgeries will likely find that their dogs are perfectly fine afterwards.  As is the case with all veterinary surgical procedures, owners will have to provide post-operative care.  This care usually involves the provision of medicine, changing of bandages, and the careful cleaning of wounds.  Oftentimes, the dog must wear a protective medical cone as well to prevent it from further damaging itself.

 

POTENTIAL COMPLICATIONS: 

 

There are a number of potential complications from Entropion.  Because Entropion causes the eyelids and hair of the dog to rub up against the eye, it can cause substantial damage to the cornea.  Among the most common complications are corneal scratches, corneal ulceration, and corneal rupture.  Entropion may also make the eye more vulnerable to various infections, leading to a number of conditions and diseases.  As the corneal damage worsens, and also due to infections, the dog’s vision is often impacted.  While some vision loss may only be temporary, untreated Entropion can lead to permanent damage.  In severe cases, dogs have even gone completely blind as a result of Entropion.

 

Unfortunately, the treatments necessary to treat Entropion may also have side effects.  Dog’s may potentially have allergic reactions to any of the topical treatments used to relieve entropion’s symptoms until surgery can be conducted, reactions which may cause further damage to the eyes.  As is the case with all veterinary surgeries, those necessary to cure ectropion may have any number of side effects.  Some dogs are allergic to anesthesia, and may experience difficulty breathing, cardiac failure, anabolic shock, or even death when put under.  In any surgery, there is the potential to do serious damage to other organs accidentally, although this risk is much reduced in Entropion surgery which is relatively non-invasive.  There is also the potential risk of severe bleeding, even potentially to death, whenever a dog is operated on, especially if the dog has an undiagnosed bleeding disorder such as Von Willebrand’s disease.  One special risk associated with Entropion surgery is that it will cause ectropion.  Ectropion is essentially the opposite of ectropion, and occurs when a dog’s eyelids hang outwards from the eye.  Ectropion can result in eye damage due to a lack of proper eye protection.  Entropion surgery can result if ectropion is the vet reshapes the eyelid too severely, and often requires its own surgery to correct.

 

HOLISTIC REMEDIES: 

 

Holistic Remedies may have a substantial impact on treating the symptoms of Entropion such as pain and eye irritation, but they generally cannot cure the underlying condition itself.  This is because Entropion is caused by a physical deformity that cannot be corrected without a surgical procedure and surgical procedures are not possible using holistic remedies.  It is possible that some cases of acquired Entropion could be resolved with holistic treatments if they cured the underlying condition causing the Ectropion, but this is a very small minority of cases.  Holistic remedies are best used to treat Entropion if they are used in conjunction with surgical procedures, especially if they are used to treat the symptoms prior to or after the surgery has been conducted.

 

There are a number of holistic remedies that may be useful in treating the symptoms of Entropion.  Most herbs used in pain reduction and as anti-inflammatories, such as German Chamomile (Matricaria recutita), Skullcap (Scutellaria sp.), and St. John’s Wort (Hypericum perforatum), can help reduce a dog’s suffering as a result of eye pain.  For puppies affected by Entropion, sometimes Silicea (derived from flint or quartz) and Goldenseal (Hydrastis Canadensis) are specifically recommended.  Owners should always remember to consult with their veterinarian before using any holistic treatment, particularly if modern anti-biotic treatments are being provided as well.

 

PREVENTION & HELPFUL TIPS: 

 

In cases of hereditary Entropion, there is essentially no possible prevention.  The condition will appear in the dog as a result of its genes, regardless of any preventative measures.  However, early diagnosis and treatment are still absolutely necessary to avoid severe complications later in life such as corneal damage and vision loss.

 

Some cases of acquired Entropion may be preventable.  One of the best ways to do so is to ensure that the dog is properly fed and exercised to prevent obesity, one of the major causes of acquired Entropion.  Rapid diagnosis and treatment of infections and injuries can also help prevent Entropion from developing, or at least reducing its severity.

 

Because Entropion is largely a hereditary condition, the best way to prevent its spread is through proper breeding.  It is almost universally recommended that any dog suffering from Entropion not be bred, and most recommend not breeding that dog’s parents, siblings, and/or offspring either.  Entropion is highly associated with breeding to certain types of conformation such as the heavily wrinkled faces of Chow Chows, Shar Peis, and Bloodhounds.  Many veterinarians are recommending that breeders work towards breeding dogs with less exaggerated features, some going so far as to recommend that official breed standards be changed.  The Canine Eye Registration Foundation (CERF) keeps records of dogs which have been diagnosed with Entropion along with providing a number of other resources for owners, breeders, and fanciers.

 

Owners should be advised that dog’s which have undergone corrective surgeries to repair Entropion are ineligible to compete in a number of official kennel club events (especially conformation events) including those of the AKC and UKC.  Many breed clubs have also placed special rules and restrictions on such dogs.  Owners of dogs which have had the necessary surgery should carefully research which events their dogs are and are not eligible to compete in.