By infection is meant that the eye has been attacked by an infectious agent such as a bacterium or a virus. Fungi and parasites can also infect the eye, but this is unusual in Europe.
It is important to distinguish eye infection from eye inflammation. Inflammation is characterized by one or more of the following symptoms: redness, swelling, heat or pain. In an infection, an inflammation usually also occurs. These two concepts are often confused with everyday life.
Cats, unlike dogs, are most often infected by viruses, which can also be the primary cause of eye infections. Many cats carry the herpes virus that lies dormant in the body and can cause problems if activated. This can happen, for example, in some form of stress. Young cats with herpes infections can have symptoms of watery eyes, runny nose and fever, while older cats usually get painful sores of varying degrees in the cornea and / or conjunctiva, ie the membrane that surrounds the eye.
Cats can also get infections for other underlying reasons. Examples of these are deteriorating tear quality which can cause a dry eye (keratoconjunctivitis sicca), irritation in the eye of eyelids that do not close tightly around the eye (entropion / ectropion) or wound damage.
It is very important to find the underlying cause of the infection so that the eye is not treated with antibiotics unnecessarily. Antibiotics should only be used to treat bacterial infections. As the bacterial infection is rarely the primary cause of the eye symptoms, the eye will only temporarily get better, usually due to the cleansing and lubricating effect of the medicine, during the treatment period.
General infections in the body can also cause symptoms from the eyes in the form of eye infections.