Eye Tumors and Eyelid Growths in Dogs

Eyelid Growths

Eyelid lumps are common in older dogs, usually over 8 years old.^13,14 At least three out of four eyelid tumors in dogs are benign.^2,13,15

Chalazion or tumor? A chalazion is a blocked oil gland that forms a firm, beige swelling, often under the inner surface of the lid. It can look like a tumor, and sometimes it's caused by one.^15,17,9 A stye is a small infected gland on the lid edge.¹⁸

Even benign lumps tend to grow. As they do, they rub the cornea and cause redness, discharge, ulcers and pain.^4,2 Removing them early can mean smaller, less invasive surgery.²

Limbal Melanoma (Dark Lump at the Edge of the Eye)

A limbal melanoma is a raised dark lump where the white of the eye meets the clear cornea.^3,1 These tumors are usually benign, and spread to the body hasn't been reported. They're more common in Labrador Retrievers, Golden Retrievers and German Shepherds.^3,10,19 Most appear at 7 to 10 years, but some show up in dogs as young as 2 to 4, and they can grow faster in young dogs.^3,20

Before treatment, an eye specialist checks with an ultrasound and a special lens how deep the tumor goes. It's usually removed with a graft to patch the eye, plus freezing or laser to kill any remaining cells. This is usually successful.^1,20 If the tumor has grown deep into the eye, the eye may need to be removed.^1,3

Dark Spots and Melanoma Inside the Eye

Not every dark spot in the colored part of the eye (the iris) is a tumor:^6,3,5

• Iris freckles: flat pigment that doesn't change the shape of the pupil. They don't grow.
• Uveal cysts: dark, round, fluid-filled balls that let light through. They're common in Labradors and usually harmless, but in Golden Retrievers and Great Danes they can be linked to glaucoma.
• Uveal melanoma (melanocytoma): a raised brown or black lump that grows over time. It's the most common tumor inside a dog's eye.

About 80% of these tumors are benign, and only about 1 in 20 spread outside the eye (up to 1 in 10 in some reports).^1,3,20 Even benign ones can grow and cause glaucoma, inflammation, bleeding inside the eye and blindness.^5,6

Because a freckle and an early tumor can look alike, your vet or an eye specialist may photograph the spot and recheck it. Small spots are typically rechecked every 4 to 6 months, along with eye pressure.⁵ Worrying changes include growth, a raised lump, a change in pupil shape, or spread into the white of the eye.^6,3

Golden Retrievers can inherit pigmentary uveitis, which causes pigment and cysts in the eye and can lead to glaucoma. Yearly exams by a veterinary ophthalmologist are recommended from about 2 to 3 years of age.^21,22

Other Eye Tumors

• Tumors on the white of the eye or third eyelid, including blood vessel tumors, are more often malignant than eyelid tumors. Sun exposure is suspected in some.^1,16
• Tumors behind the eye push the eye forward or to the side and raise the third eyelid. Most are malignant. Unlike an abscess behind the eye, they usually aren't painful when your dog opens their mouth. A CT scan or MRI is often needed.^1,23,7
• Ciliary body tumors are pale masses behind the iris.^1,24
• Lymphoma is the most common cancer to spread to the eye, often both eyes.^1,24 See lymphoma in dogs.

A tumor that starts in the eye usually affects only one eye, so tumors in both eyes suggest cancer elsewhere in the body.²⁴

Treatment

• Debulking and freezing (cryotherapy): for eyelid lumps sticking out from the lid. It can often be done under light sedation, or for some lumps without sedation, and needs no stitches.^2,15,12 About 1 in 7 lumps regrow, usually within about a year.^11,2
• Wedge removal: cutting out the lump and stitching the lid edge back together under general anesthesia. Up to about a quarter to a third of the lid's length can usually be removed this way.^15,2 Eyelids heal quickly because of their rich blood supply.¹⁴
• Laser: to shrink dark tumors limited to the iris, and for some small eyelid lumps.^5,15,1
• Eye removal (enucleation): when a tumor inside the eye causes glaucoma, inflammation, blindness or pain. It's usually curative if done before any spread.^5,20 See eye surgery.

A removed lump should be sent to a lab to confirm what it is.^4,17 There's no evidence that chemotherapy helps melanoma of the eye itself.³

Outlook

The outlook for most eye tumors in dogs is good.^3,24 Most eyelid lumps are cured by removal, although some regrow.^11,15 Benign iris and limbal tumors rarely threaten a dog's life, and dogs adjust well if an eye has to be removed.^3,20 Malignant melanomas inside the eye are less common, but they do shorten survival.¹⁹

Frequently Asked Questions

What does a tumor on a dog's eyelid look like?

Usually a pink, lumpy growth on the edge of the lid, sometimes dark. Large ones can bleed.

Are eyelid tumors in dogs cancerous?

Most aren't. At least three out of four are benign.

Is a dark spot in my dog's eye cancer?

Usually not. It may be a freckle or cyst. Have it checked and photographed so changes can be spotted.

How long can dogs live with eye melanoma?

Most melanomas inside the eye are benign and rarely spread, so most dogs live a normal life, sometimes after the eye is removed. The less common malignant type can shorten survival.

Should my dog's eyelid lump be removed?

Usually yes, while it's small, because lumps tend to grow and irritate the eye.