What is Conjunctivitis (Pink Eye)?

Conjunctivitis is inflammation of the conjunctiva, the pink membrane that lines the white of the eye and the inner surface of the eyelids. It can have many causes: bacterial or viral infections, allergies, irritation from dust, smoke, or chemicals, foreign bodies (such as misdirected eyelashes or small debris), and, in cats, it is frequently associated with feline herpesvirus infection, very common especially in kittens and cats living in groups.

Signs include redness of the conjunctiva, discharge (which can be clear, whitish, or yellow-green depending on the cause), swelling around the eyes, frequent blinking or keeping the eye partially closed due to discomfort, and, in some cases, itching, leading the animal to rub its face on the ground or with its paws.

Although many cases of conjunctivitis are mild and respond well to treatment, it is important not to confuse it with more serious conditions that also cause a red eye, such as uveitis or glaucoma, which require different and more urgent treatment. Treatment for conjunctivitis depends on the identified cause and usually includes specific eye drops. See a veterinarian if a pet has eye redness, discharge, or discomfort, especially if the eye is held mostly closed, appears painful, or the cornea looks cloudy or bluish — signs that need urgent evaluation.