They say that eyes are the window to the soul. Certainly, our dogs use them to good effect when begging for a treat. However, they are also a vital and sensitive organ that needs prompt and effective treatment if it is injured or when problems develop.
As a dog parent, knowing the symptoms of common eye disorders will mean that you are in the best position to help your pet should they ever have an issue and seek prompt treatment that will prevent them from losing their sight.
Here are the most common canine eye diseases to watch out for:
Corneal Damage
The cornea is the clear surface of the eye and is made up of three parts, with a thick, firm jelly-like layer sandwiched between two very thin sheets of cells.
The most common injuries to the cornea are minor abrasions. However, because the eye surface is so delicate and sensitive, even these can be very painful. It is often just the top layer of cells that are disrupted, and in the majority of dogs, they will heal quickly with treatment.
Occasionally, superficial grazes progress to ulcers, which can extend into the jelly layer of the cornea and even down to the base cellular layer. If these are not treated promptly, it is possible for the eyeball to rupture. Although this condition is more common in dogs with protruding eyes like the Boston Terrier and Pug, it can signal an underlying disease that requires serious medical treatment.
Foreign Bodies
This is a technical term for anything that lodges in the eye that shouldn't be there. The most common are probably grass awns (sharp grass seeds) that can lodge behind the eyelids, especially in dogs with droopy eyes or those who enjoy running through the undergrowth. They cause a great deal of pain and swelling, but usually are removed easily under local anesthetic.
More serious are foreign bodies that actually penetrate through the surface of the eye and potentially cause the eyeball to rupture. Thorns are probably the most common culprit here. To have it removed safely and repair the damage, specialist intervention will be required.
Conjunctivitis
The conjunctiva is the pink tissue that surrounds the eye and lines the eyelids. Normally, it should be a delicate salmon pink color; but if a dog develops conjunctivitis, it becomes angry, red and inflamed.
Primary conjunctivitis can be triggered by both bacterial and viral infections, dust, grit, or allergic reactions. However, it can develop because of breed-specific genetic weakness as is the case in Collies, or any condition which irritates the eye.
Dry Eye Syndrome or Keratoconjunctivitis Sicca (KCS)
The tear ducts are responsible for keeping the eye properly lubricated and clean. The tears flush out any dust or grit, are naturally anti-bacterial and keep the lids gliding smoothly over the surface.
In some dogs, especially the Lhaso Apso and small Terrier breeds, the tear ducts stop working, often because of autoimmune destruction. The deterioration comes on gradually over a few months as the tear production falls, and can be difficult to spot in the early stages. Symptoms include a green sticky discharge in the eyes, sore, red eyes, and a dark film appearing over the surface of the eye.
Treatment is possible with eye cream that stops the destruction and allows the gland to recover. However, it is best to catch this condition early because if the body's attack completely obliterates the gland, it cannot regenerate. In those cases, treatment involves either daily tear replacement drops or surgery to redirect a salivary duct to the eye.
Cherry Eye
The tear duct sits underneath the eyelids at the inner corner of the eye. In some dogs, especially Bulldogs, Dachshunds, and breeds with droopy lower eyelids, it can pop out and appear as a small red lump (a bit like a cherry) in the eye.
It is important to correct a cherry eye promptly because the dog can easily damage the delicate duct by rubbing at it, making the eye vulnerable to infection. Treatment is via surgery to sew the duct back into position. Only in extreme cases should amputation of the gland be considered, as it will leave the dog extremely prone to developing dry eye.
Cataracts
The lens of the eye is a clear, pliable ball in the center of the eyeball that focuses the light and allows dogs to see clearly. Cataracts can form in the lens and prevent the light from passing through it. They can affect just part of it, so the dog can still see but their sight may be blurry, or it can affect the total lens and leave the pet blind.
Cataracts can be congenital, present when the dog is born, or develop early in life or as the dog matures. This eye condition can affect breeds such as the English Cocker Spaniel, Belgian Malinois, Chesapeake Bay Retriever, and Boston Terrier. Cataracts can also develop as a consequence of diabetes, even if the disease is well controlled.
The only treatment for removing cataracts is with surgery (phacoemulsification). However, this can be costly, and it is important to know that most dogs cope extremely well with becoming blind and can still lead a full and active life.
Glaucoma
The eyeball is full of fluid, and a complex drainage system ensures it is kept at the right pressure. Glaucoma occurs when this fails and the pressure starts to build. Signs include a red, painful eye, a cloudy cornea, dilated pupils, and in more extremes cases, the affected eye is obviously larger. Glaucoma is a heritable disease that affects breeds such as the Cocker Spaniel, Saint Bernard, Golden Retriever, Akita, Boston Terrier, Chihuahua, and Poodle.
It is diagnosed by measuring how firm the eyeball is and treated with daily, lifelong, eye drops. Surgery, although uncommon, can be performed by specialist ophthalmologists.
In-growing Eyelashes (Distichiasis or Ectopic Cilia)
This condition develops when eyelashes or hairs near the eye turn inwards or grow into the eye, and is especially common in the English Springer Spaniel. It is extremely painful, but as the offending hair is often very small, it can be difficult to spot with the naked eye; your vet may need to use magnification to find them. Treatment is removing the hair either by plucking (this usually needs to be repeated), or with more permanent techniques like electrolysis or surgery.
Entropion and Ectropion
Some breeds of dog like the Mastiff and Bullmastiff have extremely over-sized eyelids. This can lead to them rolling inwards or outwards next to the eye.
If they roll inwards (entropion), as is the case in the Chinese Shar Pei breed, the eyelashes and hair rub the delicate surface of the eye, which is very painful and causes nasty scratches. If they roll outwards (ectropion), the exposure of the conjunctiva means it is vulnerable to damage and infections.
Both problems are cured by surgery but this can only be performed once the dog is fully grown. If your dogs have issues before this, your vet can place temporary 'facelift' type stitches to give them some relief.
Photo ©iStockphoto.com/IvonneW
