As previously mentioned, puppy and dog eye discharge can be caused by a number of illnesses. Below we have gone into more detail regarding each health condition.

Conjunctivitis - This is when the conjunctiva which is the skin tissue that lines the eyelids and is attached very close to the cornea has become infected and inflamed either due to irritations caused by allergies to pollen or grass. Conjunctivitis can also be caused by viral, bacterial or fungal infections.

This condition is also called 'pink eye' due to the symptoms leaving the Sclera (the white part of the eye) pink and in inflamed. The discharge that comes from the eye can either be a thick yellowish or greenish color - the color will also determine what has caused the infection i.e whether it is a fungal, viral, bacterial infection or something else. If an allergy has caused the infection then the eye discharge will normally be watery and transparent.

Conjunctivitis symptoms will include itching, swelling, discharge, excessive blinking, squinting and pink redness.

Canine Glaucoma - This is a serious condition caused by pressure inside the eye. If treatment is not sought quickly then your dog will gradually lose more and more sight. The buphthalmous (the globe of the eye) may be come enlarged or the enophthalmic may become sunken which will cause your dog's third eyelid to protrude slightly - glaucoma will cause pain and even changes in your dog's behavior.

Entropion - This condition is caused when your dog's eyelid has become inverted and then turned inwards so that the eyelid border has started to rub against the eyeball.

The symptoms of this illness will include the eyelid being half shut - you will also notice that your dog's eye becomes sore and very sensitive to light. Your dog will also start squinting and even trying to paw and rub at his eye.

Corneal Ulcers - Puppy and dog eye discharge may be caused by ulcers. There are two types of corneal ulcers in dogs - one that is deep and the other type that is superficial.

Dogs are quite susceptible to corneal ulcers due to their active lifestyle. Ulcers can be caused by a blade of grass scratching the eye, a fight with another dog, an ingrowing eyelash, smoke, heat and even shampoo. Puppy and dog eye discharge from corneal ulcers is more common in dog breeds that have eyes that protrude more.

Lens Luxation - This is when the lens in your dog's eye has become either completely or partially detached. This condition starts when the lens becomes subluxated (when the ligaments also known as zonules attached to the eye have become weakened). When the ligaments (zonules) have broken this is now and lens luxation. Symptoms of lens luxation will include redness and swelling.

Cherry Eye - This is another condition that can cause puppy and dog eye discharge. The scientific name for this condition is nictitans and is caused when tissued attached to the gland (which is also attached to the overall structure of the eye) in the third eyelid has become prolapsed. The third eyelid is something that humans don't have and it is present in dogs and it also contains a tear duct in the corner of the eye.

Symptoms of cherry eye in dogs can include redness swelling, a discharge and if your dog continues to scratch and irritate the eye then it may also cause an ulcer.

Ocular discharge is caused by a number of conditions including the eye problems that we have covered on this page.

Ocular dog eye discharge will very often mean that your dog has an eye disease. This discharge can vary in color, appearance and consistency. It may appear yellowy green, watery, gray (mucoid) and even bloody. Below are some of the conditions that can cause ocular discharge.

• Dry eye syndrome (Keratoconjunctivitis).
• Injury or trauma to the eye due to an injury or accident.
• Corneal ulcers
• Canine glaucoma
• Inflamed eyelids (Blepharitis)
• Abnormal eyelids
• Conjunctivitis
• Inflamed cornea (Keratitis)
• Lens luxation
• Inflammation affecting the blood vessels and iris in your dog's eye - Uveitis.
• The eyelash (Cilia) may also start rubbing against the cornea causing eye discharge in your dog - this is known as distichiasis.
• Entropion.

For any discharge that is coming from your dog's eye you will need to take your dog to the vet so that the condition can be properly diagnosed, because you can see on this page there are many conditions that may have caused the problem.

Your vet may prescribe oral or topical antibiotics if he or she thinks that it is necessary. Your vet will also probably use luke warm water to clear any crusty or moist discharge. If you are after more information on treating eye problems then take a look at our section on eye problems in dogs as we have gone into far more detail.