9 Common Eye Diseases in Dogs - Symptoms and Causes

A dog's eyes are very delicate organs. Exposed to the environment, they can be affected by various diseases and conditions. The mildest ones will cause nothing more than irritation to the eyeball, but the more serious ones can even cause blindness.

Either way, all of them will need veterinary care, since it's very dangerous for us to administer eye medication on our own. Below, we go over the most common eye diseases in dogs, their symptoms, and the care they require.

Symptoms of eye diseases

Although a wide variety of conditions can affect one or both of our dog's eyes, the signs they cause tend to be similar. If we notice any of these, we should see the vet so they can determine exactly which disease is involved. Here are some of the common symptoms:

• Pain. Can even show up as whimpering.
• Tearing.
• Eye discharge.
• Redness.
• Cloudiness over the eye.
• Crossed eyes, meaning loss of parallel eye alignment.
• Photophobia, or sensitivity to light.
• Protrusion of the nictitating membrane, or third eyelid, covering the eye to some degree.
• Hardness or softness of the eyeball.
• Irritation, eyelid swelling, or hair loss around them.
• Bulging or sunken eyes.
• Sometimes, an eye problem also reduces the dog's appetite and keeps them lethargic.

Entropion

With this issue, the edges of the eyelids fold inward onto the eye, mainly affecting the lower eyelid. It's a congenital defect, which is why we see it more often in breeds such as the Shar Pei, Chow Chow, Great Dane, Saint Bernard, or Bulldog.

The constant rubbing of the inverted eyelid against the eyeball causes tearing and crossed eyes. The cornea can also become damaged. The treatment of choice is surgical.

• Full information on entropion

Eyelid tumors

On the eyelids, the most common tumor is an adenoma of the meibomian glands. We'll see these as cauliflower-like lumps. Sebaceous adenomas can also be identified, more common in older dogs, or papillomas. These are usually removed to keep them from rubbing against the cornea and damaging it.

Prolapse of the third eyelid's tear gland

Visually, this problem is very easy to identify, since a cherry-like lump appears at the inner corner of the eye. This makes contact with the eye's surface and can cause recurring irritation and conjunctivitis that never quite clears up.

It's a congenital defect, more common in breeds such as the Cocker Spaniel, Beagle, or Bulldog, and in small dogs. Surgery is used to fix it, putting the gland back in place.

Conjunctivitis

Conjunctivitis is inflammation of the conjunctiva. It's perhaps the most common issue. We'll notice eye discharge that can be watery, mucous, or pus-filled, since there are different types of conjunctivitis. It can be caused by irritation from, for example, cold air, an allergy, or bacteria.

Because of this, although many owners treat conjunctivitis with chamomile, the truth is it's essential to see a vet to pinpoint the exact cause. Treatment usually includes antibiotics, corticosteroids in some cases, along with keeping the eye clean.

• Everything about conjunctivitis in dogs

Corneal ulcer

This is a wound affecting the cornea to varying depths. It's usually caused by trauma, but can be linked to various diseases. This tends to be a very painful problem. There's also tearing, crossed eyes, itching, or photophobia.

Sometimes the ulcer is visible as a dull area. It's very important to see the vet, since to prevent serious damage, treatment needs to start early. Medications may be prescribed for a prolonged period. If there's no improvement, surgery is used, with several techniques to choose from.

Keratitis

We'll identify this as cloudiness in the eye. It's caused by inflammation of the cornea. Intense tearing, crossed eyes, photophobia, and third eyelid protrusion appear. There are different types, but all of them share the potential to cause blindness. Interstitial keratitis, or blue eye, stands out, appearing in cases of infectious hepatitis.

There's also pannus, a pigmentary keratitis that mainly affects the German Shepherd. Some types of keratitis are progressive and incurable, so treatment can only control its progression. Other types are treated with lifelong corticosteroids under strict veterinary supervision.

Cataracts

A cataract is loss of the lens's transparency. We'll see it as a grayish film. There are congenital or juvenile cataracts affecting breeds such as the Cocker Spaniel, Boston Terrier, West Highland White Terrier, Golden Retriever, Husky, Old English Sheepdog, Poodle, or Miniature Schnauzer.

• Symptoms and treatment of cataracts in dogs

Others are acquired and are due to old age or various diseases. There are surgical techniques for removing cataracts, but not all of them are operable. Juvenile ones sometimes reabsorb on their own.

Uveitis

This is inflammation of two parts of the eye called the iris and the ciliary body. It's associated with various systemic or local diseases, though in other cases the cause is never found.

It's a painful condition, causing tearing, crossed eyes, photophobia, third eyelid protrusion, a smaller pupil, cloudiness in the eye, and softness. The vet will need to identify the underlying cause, since treatment depends on it.

• How is uveitis diagnosed and what is its treatment?

Glaucoma

Glaucoma is a dangerous disease, since it can cause blindness. It occurs when more aqueous humor is produced than is drained. This raises pressure inside the eye, which can damage the optic nerve and retina.

It can be primary, affecting breeds such as the Beagle, Cocker Spaniel, Samoyed, or Basset Hound more. Secondary glaucoma is a complication of other diseases. Glaucoma causes pain, tearing, crossed eyes, a hard eye, haziness, and an enlarged pupil. It's an emergency, since blindness can occur within hours.

Treatment focuses on lowering intraocular pressure as soon as possible. If that doesn't work, surgery is used. Chronic glaucoma enlarges the eyeball. Blindness occurs, and removal is recommended, since it will be prone to injury and pain.

• Detailed information on glaucoma in dogs

Bibliography Carlson and Giffin. 2002. Manual práctico de veterinaria canina. Madrid. Editorial el Drac.