Several conditions can lead to your cat having eye drainage. The cat will secrete anything from thin and watery, to thick and postulant, and from clear in color to yellowish or greenish. These conditions are caused by inflammation, infections, such as the flu and evasion of viruses. Sometimes it is caused by an inherited gene or a malfunction of the tear glands that cause eye drainage.
The most common condition for the drainage of the eye is called runny eye. Certain breeds of cats are more prone to leaky eyes than others.
Runny eyes can be caused by the over production of tears. Tears are produced normally to keep the lining of the eye moist. The tears then flow into the tear ducts making their way into the nose. But if there is a problem, the tears will spill onto the face and that is how we determine a cat has runny eyes.
Though it is normal for the tears to flush out material to keep the eye lining clean, sometimes foreign bodies can irritate the eyes and cause excessive tearing or drainage. For example a cat may have a piece of hair that assaults the eyeball or tiny hairs manage to manage to find their way and lodge inside of the eyelid. These hairs, dust particles or whatever the assailant is are immediately flushed out by the drainage system. The tears flow and wash the foreign bodies out and onto the face. Occasionally even the cat's own immune system cannot correct the problem and the cat would have the hairs surgically removed by a veterinarian who must put the animal under an anesthetic.
On the other hand, if there is a blockage of the ducts caused by a structural anomaly, or their was damage of some sort to the eye tear ducts, tears are still produced as a normal body function but they cannot flush out the tear duct canal in the usual manner and fall over onto the face.
Persian cats have runny eyes where a brown substance, which is especially noticeable, falls onto the face. The eye drainage is due to the shape of the eyeball, which prevents proper drainage.
Conjunctivitis is a condition where the inside of the eyelids are assaulted by a foreign substance like dust or hair and irritates the eyes. They will redden and then tears will drain onto the face. Dust and wind from traveling in a car will also cause the conjuctiva to become inflamed and redden.
Damage to the cornea in the eyes due to scratches will cause eye drainage to spill out onto the face.
Glaucoma is a condition where too much fluid builds up and spills over.
If both eyes are tearing up at the same time and drainage occurs, it is possible that your cat is suffering from allergies.
Influenza will also cause watery eyes and if left untreated can cause serious damage to the cornea and render a cat blind.
Viral infections can cause watery eyes. The secretion would have a clear consistency but can change to a thick yellowish pus as the infection worsens.
Damage to the Iris - caused by various viruses such as Feline Infectious Peritonitis (FIP) virus, Feline Leukemia Virus (FeLV), and Feline Immunodeficiency Virus (FIV)
Clear to yellowish green fluid secretion
Brown stains below the eyes
Change of eye colour and shape of eyes
Pus in the eyes
Dark patches in the eye
Pawing the eye
Lesions or debris
Diagnosis depending upon the cause for concern:
Fluorescein staining - a dye to determine if there is damage to the cornea
Treatment for various eye drainage conditions
Saline solution to wash out the eye
Drug therapy, medications, anti-inflammatories
Though eye drainage is normal in certain cats, like the Persian, it still should be discussed with your veterinarian. Sometimes the animal might have a more serious underlying condition that needs immediate attention. To the untrained eye what might appear as a harmless over production of tears may end in your cat losing its eyesight