Feline conjunctivitis is an irritation, inflammation or infection that affects the soft tissue around one or both eyes. Although there are several causes, it is the most common ocular ailment of cats and usually easy to treat. This article describes the feline conjunctivitis and describes several treatment options.
Feline conjunctivitis usually presents as redness and/or swelling around the conjunctiva, that is, the tissue around the eye. The tissue may discharge pus as well. In some cases the eye will appear to squint or swell shut. In other cases conjunctivitis causes red discolouring of the sclera, the white portion of the eye, akin to pink eye. While cats have far fewer eye problems than dogs, bouts of conjunctivitis tend to reoccur over a cat's lifetime.
The causes of conjunctivitis include allergies induced by pollen or plants or from infections related to viruses, bacteria and fungi. The colour of pussy discharge indicates its cause. Conditions caused by infections tend to secrete thick yellow or green discharge around the eye, while allergy related discharge is more watery and generally clear. Squinting becomes more pronounced if the cornea has become ulcerated or eroded. There are three main bacteria responsible for infection: feline herpesvirus-1 (FHV-1), feline chlamydia and feline mycoplasma.
Usually the cat's medical history and symptoms are enough to diagnose the condition, although sometimes cultures and other tests are preformed. Eye drops and ointments are the two primary methods of treating feline conjunctivitis. Eye drops are applied one or two drops at a time, every few hours, while ointments last longer and need only be applied two to three times per day. Anti-inflammatory medication is effective at treating allergy induced conjunctivitis. Most of these medications include hydrocortisone as the active ingredient. If treating an infection induced case of conjunctivitis, then bactericidal or fungicidal ointments or solutions may be applied. In severe cases, oral antibiotics are used in tandem with topical treatments. In cases requiring frequent application of preparations, a local administration is performed under the conjunctiva. Most cases of conjunctivitis clear up within a week or two, although treatment should be continued for several days after the afflicted eye or eyes appear to return to normal.
Although hydrocortisone is great at minimising eye inflammation, it may hinder the healing or worsen an ulcerated cornea. As such, don't treat conjunctivitis if an ulcerated cornea is suspected. FHV-1 conjunctivitis cannot be cured, only controlled. While most of the cats on the planet carry this bacteria, some go their entire life without contracting conjunctivitis, or have years between flare-ups. Long-hair cats are more susceptible to many forms of conjunctivitis because their eyes are more prominent and less protected by the eye socket.
The majority of conjunctivitis is not fatal, however an advanced case can spread to other structures of the eye, causing impaired vision and corneal ulcers. Conjunctivitis can also signify a feline immunodeficiency virus infection, a much more serious disease.