Your dog's tarsal glands, located within his eyelids, are a type of sebaceous gland. They secrete meibum, which helps keep eyes lubricated. These glands might develop growths, known as adenomas, that you can see sprouting out of your dog's eyelid. Fortunately, the overwhelming majority of these tumors are benign.
Also known as meibomian gland tumors, tarsal gland adenomas are the most common eyelid growth in canines. These slow-growing benign tumors can be unsightly. Rarely, a meibomian epithelioma, a low-grade but malignant tumor, develops. Even more rare is a meibomian carcinoma or high-grade malignancy. If your vet surgically removes the growths, they'll be tested to see if cancer exists.
An adenoma growth might share the same pigment as the dog's skin or have a different coloration. The adenoma usually appears at the eyelid's margin, where the duct secreting meibum is located. It generally grows outward from the eyelid rather than toward the eye. Some tumors do grow under the eyelid. Dogs often have multiple adenomas on both the lower and upper lids. If a dog starts scratching or rubbing the growth, they can bleed.
While any dog might develop a tarsal gland adenoma, they generally occur in dogs over the age of 10. Males and females are equally affected, although the growths occur in spayed females more often than in neutered males or intact males and females. Certain breeds are more prone to these growths than others. These include the American Eskimo, the beagle, the Siberian husky, the Samoyed, the Labrador retriever, the West Highland white terrier, the keeshond, the German short-haired pointer and the poodle.
If the adenoma isn't bothering your older dog and is basically a cosmetic problem, you and your vet might decide not to treat it. You must keep tabs on the growth in case it does interfere with your dog's sight or make him uncomfortable. If your dog frequently rubs his eye because of the adenoma, he could end up with conjunctivitis. If the growth is large enough, he might have trouble blinking. Your vet can surgically remove the adenoma, either conventionally or with a laser, taking care to excise the entire growth. If it's not entirely removed, it will grow back. Even if one particular adenoma is completely eradicated, that doesn't mean a different one won't spring up.
- Animal Eye Care: Eyelid Tumors
- Veterinary Specialty Center of Tucson: Ophthalmology: Canine Eyelid Tumors - Meibomian Gland Tumors and Eyelid Melanomas
- The Canadian Veterinary Journal: Diagnostic Ophthalmology
- Merck Veterinary Manual: Ocular Neoplasia in Dogs
- University of Calfornia Davis School of Veterinary Medicine: Eyelids
- Oncolink: Meibomian Tumors
- Jupiterimages/Photos.com/Getty Images