Cats produce tears, but unlike humans, this fluid serves a purely physical, non-emotional purpose. Feline tears are produced constantly to maintain eye health. Therefore, the presence of tears on a cat’s face is not a sign of emotional distress, but rather an indication that the eye’s protective mechanisms are working or that a medical issue is present.
The Purpose of Feline Tear Production
Tears form a complex, trilaminar fluid called the precorneal tear film, spread across the eye with every blink. This film has three layers: an outer lipid layer to slow evaporation, a thick aqueous layer (water, salts, proteins), and an inner mucin layer that adheres to the cornea.
The tear film maintains a smooth optical surface for clear vision. The aqueous layer delivers necessary oxygen and nutrients to the cornea, which lacks blood vessels. Tears also function as a defense system, flushing away dust, debris, and environmental irritants. The fluid contains natural antimicrobial agents, such as lysozyme, which help protect the eye from infection.
The Feline Lacrimal System
Tear production involves multiple glands, primarily the lacrimal gland located above the eye and accessory glands within the third eyelid (nictitating membrane). These glands continuously secrete the tear film components onto the eye’s surface. Eyelid movement and the sweep of the third eyelid distribute the fluid evenly across the cornea.
To prevent overflow, the fluid must drain. Drainage begins at two small openings called puncta, located on the inner corner of the upper and lower eyelids near the nose. Tears travel through small canals into the lacrimal sac. From there, the fluid flows down the nasolacrimal duct, draining into the nasal cavity and throat.
Understanding Excessive Tearing and Discharge
Visible, excessive tearing that runs down a cat’s face is medically known as epiphora, a sign that the production and drainage system is unbalanced. Epiphora can occur either because the tear glands are overproducing fluid in response to irritation or inflammation, or because the nasolacrimal duct system is obstructed and cannot handle the normal volume. Common irritants that cause reflex overproduction include allergies, dust, smoke, or a condition like conjunctivitis, which is often triggered by viral infections such as Feline Herpesvirus.
Improper drainage is frequently caused by anatomical issues, particularly in brachycephalic breeds like Persians and Himalayans. These flat-faced cats often have shallow eye sockets and curved or kinked nasolacrimal ducts, preventing the tears from entering the puncta correctly and causing them to spill over the lower eyelid. Blockages can also occur within the duct itself due to inflammation, scarring from previous respiratory infections, or foreign material.
The appearance of the discharge is an important indicator of the underlying cause, differentiating simple overflow from a more serious issue. Clear, watery discharge is typically associated with epiphora or irritation, while thick, discolored, or sticky discharge suggests the presence of pus and a bacterial or secondary infection. The constant moisture caused by chronic tearing can also lead to reddish-brown staining of the fur and skin irritation beneath the eyes. Any change in the type or amount of discharge warrants an examination to identify and address the source of the problem.