Conjunctivitis in Cats
Feline conjunctivitis is a common eye ailment, but unfortunately the exact cause of the conjunctivitis is often not defined. In cats, there are a variety of diseases that can result in conjunctivitis. Upper respiratory infection. These infections usually involve viruses (especially feline herpesvirus and feline calicivirus), bacteria and chlamydial agents. Signs of conjunctivitis are often present in both eyes, and other signs such as sneezing, nasal congestion and discharge, lethargy, fever and decreased appetite may be noted.
Herpesvirus. Once a cat has been infected with herpesvirus the virus is rarely cleared from the body. Instead, the virus becomes latent (or quiet) and may cause repeated bouts of conjunctivitis throughout the cat's lifetime. These recurrent bouts of conjunctivitis may be triggered by stress, illness, certain medications or other infections.
Exposure to environmental irritants or foreign material. Such irritants can include cigarette smoke, household chemicals and cleaners, dust, pollen, plant material, and sand.
Infection and inflammation of the eyelids and cornea. Because the conjunctiva is physically adjacent to both the eyelids and the cornea, any infection or inflammation of these tissues may result in conjunctivitis. Examples include corneal ulcers, certain forms of keratitis, blepharitis (inflammation of the eyelids), and skin diseases that affect the eyelids.
Allergies. Allergy-related conjunctivitis is uncommon; it is much more common in the dog.
Primary bacterial infections. Without associated eye disease, these infections are a rare cause of conjunctivitis. It is much more common for bacteria to take advantage of inflamed conjunctiva, and then to invade this inflamed tissue to create a secondary infection.
Trauma to the conjunctiva, eyelids, cornea or eye itself.
Inflammation from within the eye. Occasionally outward extension of inflammation can reach the conjunctiva, resulting in conjunctivitis. In these instances the inflammation within the eye is the primary concern.