by Jennifer Coates, DVM
There’s something special about a cat’s eyes. Maybe it’s those vertical pupils, or the incredible colors they come in (sometimes more than one at the same time, a condition called heterochromia). While pet parents might argue over the relative beauty of a Siamese’s baby blues or a Bombay’s coppery gaze, we can all agree that maintaining the health and function of our cat’s eyes is priority #1.
In this slideshow, we’ll cover seven common cat eye problems and what can be done about them.
Eye infections are quite common in cats and can be caused by viruses, bacteria, fungi, and even parasites. In some but not all cases, the symptoms of an eye infection — redness, swelling, discharge, rubbing, and/or squinting — are also accompanied by sneezing and nasal discharge. Treatment depends on the underlying cause. Mild viral infections will often resolve with symptomatic care — rest, keeping the eyes and nose clear, and encouraging good hydration and nutrition. In more severe cases, veterinarians will prescribe topical eye ointments and/or systemic medications that help the body rid itself of the specific microbe that is to blame for the infection.
Most eye infections in cats resolve with appropriate treatment, but in some cases they can be a chronic or recurrent problem or lead to the development of serious secondary conditions like corneal ulcers. Many of the causative microbes are highly contagious to other cats, and a few, like Bartonella bacteria and Toxoplasma parasites, can even be transmitted to people.
The cornea is the clear tissue on the surface of the eye through which light passes. Corneal ulcers are open sores characterized by a loss of tissue from the surface of the eye that can be caused by infections, injuries, inadequate tear production, or anatomical eye abnormalities. When a cat has an ulcer, the affected part of the cornea may appear cloudy. Other symptoms include eye pain, squinting, redness, and sometimes discharge.
Mild, superficial corneal ulcers will usually heal with proper treatment, which may include dealing with any underlying causes, antibiotic drops or ointment, and pain relief. Deep corneal ulcers may also require surgery or other procedures to promote healing. Without appropriate treatment, cats may develop an area of dead tissue over the ulcer (called a corneal sequestrum) or, worst of all, the eye may rupture leading to permanent blindness and disfigurement.
Trauma is another relatively common cause of eye problems in cats. Cats who go outside or live in less-than-harmonious multi-cat households often fight with other cats, which can lead to scratches, punctures, or lacerations to the surface of the eye. Other causes of eye trauma in cats include foreign material that gets lodged under an eyelid, predator attacks, falls, and being hit by a car. Mild trauma typically causes a cat’s eye to become red, swollen, and painful. Drainage from the eye may also be evident. With severe traumatic injuries, a cat’s eye or surrounding structures may be visibly damaged and the eye can even come out of its socket, a condition that is called “proptosis.”
Treatment for eye trauma can range from topical antibiotic drops/ointments and pain relief, to surgery to help repair or remove severely damaged eyes.
Itchy, watery eyes are a common symptom of allergies in people, but this is less common in cats. On the other hand, if something irritating — dust, strong fragrances, tobacco smoke, etc. — does get into a cat’s eyes, it’s not unusual for redness, drainage, and discomfort to develop. In these cases, rinsing out a cat’s eyes with an eye-wash solution can help, as long as your cat is cooperative. Keep in mind, however, that the symptoms of eye irritation are really indistinguishable from other, more serious eye problems, so if your cat’s condition worsens or fails to improve, you need to make an appointment with a veterinarian.
The iris is the colored rim of tissue that surrounds the dark pupil at the center of a cat’s eye. Normally, a cat’s eye color doesn’t change in adulthood (it is normal for a kitten’s blue eyes to change to a different color as he or she matures). However, a condition called iris melanosis can result in the development of brown “freckles” or patches of pigment on the iris, usually in middle-aged to older cats. Iris melanosis typically does not cause any problems, but severe cases may result in dysfunction of the iris and sometimes glaucoma (increased eye pressure).
While iris melanosis is usually not a serious condition, it can be confused with iris melanoma, a potentially serious type of cancer. If you see a new patch of dark pigment on your cat’s iris, bring it to your veterinarian’s attention. He or she should be able to tell you whether it is anything to worry about after performing an eye exam.
Fluid is constantly being produced inside and draining from within the eyeball. When fluid drainage is blocked, eye pressure increases, resulting in glaucoma.
Glaucoma can be caused by anatomic abnormalities within the eye, infection, inflammatory disorders, trauma, tumors, an abnormal shift in the eye’s lens, and more. Cats with glaucoma generally are in a significant amount of pain. Their eyes may be red, cloudy, weepy, and in severe cases, visibly enlarged.
Glaucoma is an emergency. Cats can lose their vision and possibly even their eyes if they do not receive timely treatment with medications to lower eye pressure. If an underlying cause to the glaucoma can be identified and successfully treated, the glaucoma should resolve as well. When this is not the case, long term medical management for glaucoma becomes necessary. If a cat’s glaucoma cannot be adequately controlled, surgery (oftentimes to remove the affected eye) to keep the cat comfortable may be necessary. When a cat’s glaucoma has a genetic underpinning, it is common for both eyes to eventually be affected.
The lens is located in the middle of the eye and is normally clear, but sometimes all or part of the lens develops a cloudy cataract. Cataracts block light from reaching the back of the eye, resulting in poor vision or blindness, depending on their severity. Cataracts are often confused with a normal aging change that affects cat lenses called lenticular sclerosis. Both conditions give the pupils (the normally black center to the eye) a white, grey, or milky appearance, but a veterinarian can tell the difference with a standard eye exam.
Cataract surgery is available for cats when their vision is severely compromised. If this is not an option, it is important to recognize that most cats adapt very well to having poor vision as long as they live indoors.
Of course, cats can develop eye problems other than those discussed here. Many eye problems in cats have similar symptoms and can therefore be difficult to differentiate, and some can be true medical emergencies. If you have any concerns about your cat’s eye health, talk to your veterinarian as quickly as possible.