Red Eyes
Red eyes is common in both cats and dogs. Pets get red eye when blood vessels of the conjunctiva (the pink lining of the eyeball and eyelids), sclera (white covering of the eye), or cornea (clear surface of the eye) become enlarged or more numerous. It may also occur with inflammation of the structures inside the eye, with glaucoma (high pressure within the eye) or with certain diseases of the orbit (eye socket). The eyes can become irritated from allergies caused by pollens, grasses, etc., or from infections caused by viruses, bacteria, or fungi. Either one or both eyes can become red, depending upon the cause of the problem. It is recommended to keep your pets eyes clean, eliminating the cause of the conjunctivitis with appropriate medication.

Cherry Eyes
The medical term for 'cherry eye' is nictitans gland prolapse, or prolapse of the gland of the third eyelid. Unlike people, dogs and cats have a 'third eyelid' that contains a tear gland and is located in the corner of each eye. Under normal circumstances, this gland is not visible and aids in the production of tears. This gland can prolapse or come out of its normal position and get swollen creating the condition. Cherry eye is an uncommon occurrence with cats.

Dry Eyes ( Keratoconjunctivitis Sicca or KCS)
Keratoconjunctivitis sicca (KCS) is a Latin medical term used to describe a condition of decreased tear production. The term technically means "inflammation of the cornea and conjunctiva from drying." When the watery part of the tears is not produced in adequate amounts, the eye becomes inflamed, leading scarring and pigmentation of the cornea. This may result decreased vision. Another commonly used term to describe this disease is "dry eye."

Ocular (Eye) Discharge
Ocular discharge is a common symptom of eye disease. Discharge may suddenly or gradually develop. The discharge may appear to be watery, mucus-like, or bloody. The amount of discharge is a good indication of how serious the disease is.