Unfortunately, entropion is very common in dogs. In most cases, it’s due to the conformation of their facial tissues, and first appears as a puppy – almost always before they reach 6 months of age (at which point, in most breeds, their faces reach their adult conformation and shape).
What is entropion?
Entropion is the name given to “inward turned eyelids”. The inside of a dog’s eyelid is smooth and pink, so it slides smoothly over the eyeball. However, if it is turned inwards even slightly, the hair and eyelashes rub against the eye, causing irritation, pain and inflammation. In severe cases, entropion can even result in corneal ulcers (“scratches” on the eye’s surface), pigmentary keratitis (dark pigment-filled spots forming on the cornea) or even rupture of the eyeball itself. Even moderate cases, if not resolved, may affect the dog’s vision.
What causes it?
In most cases, it is genetic – essentially, their faces are too big for their skulls, meaning the eyelids “bulge” inwards. It is particularly common in Shar-Peis and Chow Chows, but may affect any dog. Sometimes, a different form of the condition develops, called Spastic Entropion. This occurs when irritation or damage to the eye triggers the dog to squeeze their eyes so tightly shut, that the eyelids turn inwards and rub. Of course, in some cases, a physical entropion may trigger a spastic one: cases have been described where first-time breeders of Chows and Shar-Peis have been concerned that the puppies haven’t opened their eyes by 5 weeks of age, only to find that the pup’s entropion was so severe that they’ve been keeping them clamped shut.
How is it diagnosed?
In most cases, the main presenting symptom is a sore or runny eye; occasionally, there can be a nasty-looking discharge (especially if there’s an ulcer and/or an infection), or a very painful eye that the dog holds clamped shut.
Generally speaking, the condition can easily be detected by simple examination of the eye – the turned in eyelids are usually really obvious. However, it is important to see whether there is some underlying condition (e.g. conjunctivitis, or a foreign body in the eye), and to assess how much damage has been done to the front of the eyeball. For this, we will usually use a special dye called fluorescein, which glows green when it contacts damaged corneal tissue.
How is it treated?
We’ll there are a lot of options – and which is right for your dog will depend on which part(s) of the eyelid are inverted, how severe they are, and how old the dog is. Obviously, of course, any possible causes of spastic entropion should be treated and resolved first!
The more common treatments we use for primary entropion include:
- Wait for them to grow out of it. This can work if it is a very mild entropion that isn’t damaging the surface of the eye. In this situation, we would prescribe lubricants to help everything slide easily over the eyeball, and hope that as the puppy grows up, they will “grow into” their face.
- Temporary tacks. If the entropion is more severe, but there is every expectation that the bones of their skull and face will grow sufficiently to resolve the issue, it is possible to insert a small suture just to hold the eyelid away from the eye while they grow. This usually needs to be repeated every 2-4 weeks until six months of age or thereabouts (possibly a little longer for giant breed dogs, who take longer to reach their full growth).
- Eyelid Surgery. If the dog is over six months of age and there is no sign that the symptoms have resolved on their own, it may be necessary to carry out surgery to turn the eyelid outward slightly. There are a range of different surgical techniques, but they all rely on removing a strip of skin to “tighten” the eyelid, preventing it from touching the eyeball. Obviously, this isn’t appropriate in a young puppy (doing so might result in an outward turned eyelid, or ectropion, in adulthood); but if they’ve reached an adult conformation without the problem sorting itself out, it is the best solution.