A few common causes of eye problems are cataracts, conjunctivitis, corneal scratches, entropion, glaucoma, nuclear sclerosis, and a prolapsed eyeball. Learn more about these common conditions now.
Something different is going on if your pet's eyes develop a gray, bluish, or whitish cast or form little silver specks. These changes, known as cataracts, occur when the lens (the part of the eye that focuses light rays) gets slightly hard and loses its transparency. The change of eye color is caused by the light rays bouncing off the lens rather than passing through.
Almost all dogs and cats will have cataracts to some degree by their eighth birthdays. The condition is especially common in pets that have diabetes or have had eye injuries in the past. But the way that cataracts affect your pet are not at all comparable to the way they affect humans. Most dogs and cats will adapt nicely. For one thing, cataracts are rarely severe enough to cause blindness. In addition, dogs and cats can compensate for the loss of vision by depending more on their other senses -- especially their senses of smell and hearing. It is only when cataracts are severe or pets are having trouble coping that vets recommend surgery to remove them.
The surface of the eye is exceedingly delicate, which is why it has a tough, but nearly invisible layer of protection called the conjunctiva. The conjunctiva's job is to protect the eye from wind, grit, and other foreign objects.
If something gets lodged inside the conjunctiva, the eye will get sore, red, and watery. This condition, called conjunctivitis, can be very painful. "If the inflammation doesn't heal within a few days, an infection may crop up," says Nick A. Faber, D.V.M., a veterinary ophthalmology resident at the University of California School of Veterinary Medicine, Davis. You will know there is an infection because the discharge from the eye, rather than being clear and runny, may turn a nasty yellow or green color, and there may be a thick, crusty material on the eyelids.
You can often treat conjunctivitis at home by flooding the eye with saline solution or artificial tears. Just be sure to avoid artificial tears that also contain ingredients for relieving red eyes since they may be harmful for pets. If something is stuck inside an eyelid, you can swab out the speck with the tip of a handkerchief or tissue. If an infection has already taken hold, however, your vet will need to treat it -- usually with an antibiotic ointment made especially for the eyes or with oral medications.
The transparent tissue that forms the front of the eye is called the cornea. When the cornea gets scratched -- by a bit of dust or a low-hanging branch, for example -- the eye can get red, watery, and very sore.
Corneal scratches are common in dogs and cats simply because they tend to run first and look where they are going afterward. "It doesn't take much for an injury to scratch the cornea," says Nancy Willerton, D.V.M., a veterinarian in private practice in Denver.
Corneal scratches usually aren't serious and will heal on their own. If the eye is still sore after 48 hours or if your pet is blinking repeatedly or squinting to block out the light, you should call your vet right away.
Some pets are born with a slight deformity in which the eyelid rolls inward, causing the eyelashes to constantly brush against the surface of the eye. This condition, called entropion, can affect both eyelids in dogs with big heads and loose facial skin such as Saint Bernards, shar-peis, and Chow Chows. In cats and some breeds of dogs like golden and Labrador retrievers, entropion often affects the lower lids only. "This is a very irritating condition, causing eyelid swelling, tearing, and even corneal scratches," says Dr. Willerton.
Your vet may suggest that you keep your pet's eyes lubricated by putting in drops of saline solution. For older pets who have finished growing, veterinarians sometimes recommend surgery, which will prevent the lids from rolling under.
The eyes are naturally filled with fluids, which create just enough internal pressure for the eyeball to hold its shape. But in pets with glaucoma, pressure inside the eyes rises to dangerous levels, causing pain and possibly blindness, says Christopher J. Murphy, D.V.M., associate professor of ophthalmology at the University of Wisconsin School of Veterinary Medicine in Madison.
Glaucoma occurs more often in dogs than in cats, and in some breeds of dogs more than others. Cocker spaniels and basset hounds have an especially high risk of glaucoma. In both cats and dogs, it is much more common as they get older, says Dr. Murphy.
You can't diagnose glaucoma at home, but warning signs include red or cloudy eyes, teariness, a dilated pupil, a blue layer across the surface of the eyes, and possibly bulging eyes. Since glaucoma is painful, your pet may be squinting or pawing his eyes as well.
You need to see your vet immediately if you suspect that your pet has glaucoma. Once it is diagnosed, it can easily be treated with medications that help bring the pressure down.
The eyes normally shed and replace cells at a roughly the same rate. As the eyes get older, however, they become less efficient at discarding old cells. Instead of being washed away, discarded cells accumulate, thickening the eyes and causing them turn slightly blue. Vets refer to this condition as nuclear sclerosis.
Nuclear sclerosis usually isn't serious. Some pets will lose a little vision, but in most cases it doesn't cause any problems at all, says Dr. Faber.
It is scary to think about, but an accident or a hit on the head can cause the eyeball to literally pop out of its socket, a condition called prolapsed eyeball, or proptosis. "While this can occur in any breed of dog or cat, pets with bulgier eyes, like pugs, Pekingese, and Persians, are at greater risk simply because their eyes stick out farther to begin with," says L. R. Danny Daniel, D.V.M., a veterinarian in private practice in Covington, Louisiana.
This prolapsed eyeball is obviously quite serious. Once the eyeball pops out, the eyelid clamps down behind it, trapping the eyeball outside the socket and possibly cutting off the supply of blood. It is essential to get the eye back into its socket within about 10 minutes in order to preserve your pet's sight, says Dr. Daniel. If you can't get to your vet's office immediately, it is possible to replace the eye yourself, but it is best to get to a veterinarian immediately, he adds. (For more information on how to perform this procedure, see Bulging eyes)
Back to the Symptom Solver Main Page
Copyright 1999 Rodale Press, Inc. All rights reserved.