The conjunctiva is the tissue that covers the inner part of the eyelids, the third eyelid, and the white part of the eye. Normal conjunctiva is clear-pink, moist and glistening. It serves as a protective barrier and contains cells which produce a film that traps foreign material and debris.

Conjunctivitis describes the condition of these membranes when they are reddened, congested and painful. Conjunctivitis is the most common cause of “red-eye” in animals. Causes of conjunctivitis are numerous; however, it is important to establish whether the disease is primary or secondary to another factor.

Feline conjunctivitis is generally caused by primary ocular infection. Canine conjunctivitis is often secondary to other disorders, such as foreign bodies, tear production deficiencies, or irritants.

Conjunctivitis may occur in only one eye or it may be present in both. Causes include viruses, bacteria, chemicals, foreign bodies, wounds, smoke, internal diseases, allergic reactions, and tear production problems.

When conjunctivitis is suspected, it is important to determine the underlying cause. Your veterinarian is equipped to perform a complete examination of your pet’s eyes. Blood tests along with conjunctival scrapings and cultures may be needed to help determine the cause of the problem.