Cancers and Tumors of the Eye in Dogs

The different tissues of the eye and associated structures can develop primary tumors or can be the site of spreading tumor cells. Eyelid tumors are the most frequent group of eye tumors in dogs. Adenoma (a benign tumor) and adenocarcinoma (a malignant tumor) of the meibomian glands in the eyelid are the most common lid tumors. Because these tumors tend to be disfiguring as well as irritating to the dog, they are usually surg

Eyeworms (Thelazia californiensis and T. callipaeda) are parasites found in dogs, cats, and other animals, including humans, in the western United States, Europe, and Asia. They are whitish, 0.5 to 0.75 inches (7 to 19 millimeters) long, and move in a rapid snake-like motion across the eye. Up to 100 eyeworms may be seen in the conjunctival sac, tear ducts, and on the conjunctiva under the nictitating

Eye disorders can occur because of diseases affecting other parts of the body. They can occur with inherited, infectious, degenerative, and cancerous disorders. Often, discovering a change in the eyes can help uncover the systemic disorder sooner than if eyes had not been examined. Diseases affecting the blood vessels or nervous system are likely to produce changes in the eyes. If your dog has a disease that affects both eyes, your veterinarian will often look for diseases in the

Severe prolapse (slipping out of place) and/or bulging of the eye can be caused by trauma. It is common in dogs. The chances of a good outcome depend on the severity of the injury, the breed of dog, depth of the eye socket, the condition of the eye and how long it was displaced, and other damage near the eye. The eyeball should be put back in place surgically as soon as possible if the animal is in good enough health to have general anesthesia. Treatment includes ant

The orbit is the bony cavity that contains the eyeball and all of its associated muscles, vessels, and nerves. Inflammation of the orbital area, called orbital cellulitis, is common in large and hunting breeds of dogs and much less common in other breeds. This condition may be caused by foreign objects in the eye (such as a porcupine quill, thorn, or grass awn) or by an infection that spreads from another part of the body. The most co

The optic nerve carries the electrical impulses from the eye to the area in the back of the brain where vision is sensed and interpreted. Injury to the optic nerve usually leads to partial or complete loss of sight.   Optic Neuritis The most frequent optic nerve disease is optic neuritis, which is inflammation of the optic nerve. When it affects both eyes, signs include dilated pupils that do not respond to

The ocular fundus is the back of the eye opposite the pupil and includes the retina, the membrane (the choroid) between the retina and the white of the eye, and the optic disk. Diseases of the ocular fundus may occur on their own or as a part of generalized diseases. Inherited abnormalities, trauma, metabolic disturbances, generalized infections, tumors, blood disorders, high blood pressure, and nutritional deficiencies are possible underlying cau

The lens is a soft, transparent tissue that sits behind the iris. It helps focus incoming light onto the retina. Common disorders of the lens include those that affect its transparency (such as cataracts), and those that affect the position of the lens.   Cataracts A cataract occurs when the lens becomes cloudy or opaque, which effectively blocks light from reaching the retina. This causes a lo

Dogs, like people, can develop glaucoma. Glaucoma occurs when an imbalance in production and drainage of fluid in the eye (aqueous humor) causes a buildup of fluid that increases eye pressure to unhealthy levels. The increased pressure can cause the destruction of the retina and optic disk (the spot where the optic nerve enters the eye). Open-angle glaucoma is a painless and gradual development of blind spots or loss of vision over a

The uvea (or the uveal tract) is the colored inside lining of the eye consisting of the iris, the ciliary body, and the choroid. The iris is the colored ring around the black pupil. The ciliary body is the set of muscles that contract and relax to allow the lens to focus on objects; it is also the major source of aqueous humor, the clear fluid within the eye. The choroid is the inner lining of the eyeball and extends from the ciliary muscles to the optic nerve at the