Bulging Eyes on Dog

This is an emergency. Dislocation of one or both eyeballs is a common problem in dogs with large, bulging eyes such as Boston Terriers, Pugs, Pekingese, Maltese, and some spaniels. It is generally caused by dog bites and other types of trauma. Struggling with these dogs while attempting to hold and restrain them for any reason can cause the eye to bulge out so far that the eyelids snap shut behind the eyeball. This prevents the eyeball from returning to its socket and may pull on and damage the optic nerve

Treatment: A dislocated eyeball is an extremely serious condition that may cause loss of vision. Shortly after the eye dislocates, swelling behind the eye makes it extremely difficult to return the eyeball to its normal position. Proceed at once to the nearest veterinary hospital. Carry the dog, if possible. Cover the eye with a wet cloth. Prevent the dog from pawing at the eye.

If it appears that veterinary help will not be available within 30 minutes, consider attempting to reposition the eyeball yourself. This requires at least two people: one to restrain and hold the dog and the other to reposition the eye. Lubricate the surface of the eye with K-Y or petroleum jelly and lift the eyelids out and over the eyeball, while maintaining gentle inward pressure on the globe with a wad of moist cotton. If you're not successful, make no further attempt. Seek professional assistance. Even if you can replace the eyeball, you should visit your veterinarian for follow-up care, because the delicate tissues may be damaged.

After the eye has been replaced, your veterinarian may suggest a surgical procedure to prevent a recurrence.

Other Causes of a Bulging Eye

Abscesses, hematomas, and tumors in the retrobulbar space behind the eye can push the globe forward and cause bulging.

A retrobulbar abscess (an abscess behind the eyeball) is an extremely painful condition that comes on rapidly. The face around the eye is swollen and the globe is extremely tender to finger pressure. Dogs experience great difficulty opening and closing their mouths. A retrobulbar abscess must be surgically drained.

Retrobulbar hematomas (blood clots behind the eyeball) also develop suddenly. They occur with head injuries and can appear spontaneously in conjunction with some bleeding disorders.

Tumors in the retrobulbar space produce a gradual bulging. Unlike the two conditions just described, they are relatively painless.

Chronic glaucoma can lead to increased eye size and protrusion.

Enophthalmos (Sunken Eye)

When an eye recedes, the third eyelid usually slides out over the surface of the eyeball and becomes visible. The treatment of a sunken eye is directed toward the underlying cause.

Both eyeballs may recede when there is loss of substance in the fat pads behind the eyes. This occurs with severe dehydration or rapid weight loss.

There is a retractor muscle, which, when it goes into spasm, pulls the eyeball back into its socket. Tetanus produces spasms of the retractor muscles of both eyeballs, along with the characteristic appearance of the third eyelids.

When only one eye is involved, the most likely cause is a painful eye. Nonpainful causes include nerve damage following a neck injury or a middle ear infection. With this condition, called Horner's syndrome, the pupil is small on the affected side. Finally, after a severe eye injury, the eye can become smaller and sink into its socket.

This article is excerpted from “Dog Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.