Medically reviewed by Paula Simons, DVM
Seeing a new lump on your dog is worrisome. You hear so much about cancerous lumps that even harmless sebaceous adenomas in dogs can cause fear.
Try looking up information on any type of skin condition in dogs and you’ll likely end up more confused than when you started.
In this post, you’ll learn all about sebaceous adenomas in plain language.
You’ll discover exactly what they are, which dogs are more likely to get them, and what you can do to treat them at home.
It’s always a good idea to get a veterinarian to examine new or suspicious lumps on a dog. That’s just common sense.
The reality is that without a fine needle aspiration or biopsy, the veterinarian can’t accurately give a diagnosis.
The reality, however, is that sebaceous adenomas are so commonly seen by a trained eye that biopsy may not even be required.
What Causes Sebaceous Adenomas in Dogs?
Your dog’s skin is complicated.
The epidermis, which is the uppermost level, covers and protects your dog against heat, cold, and protects the organs from damage.
Hormonal and Chemical Changes
Any hormonal or chemical disruption to the skin can cause disturbances that result in infection, inflammation, clogged pores, and even infected hair follicles.
As we age (and as our dogs age), the skin changes. The natural oils and elasticity of youth disappear. Your dog’s skin may become drier or oilier.
The coat may thin and even the texture of the fur might change somewhat.
All of these hormonal shifts and changes in the body trigger the epithelial cells into action.
Sometimes, the result is a cancerous growth. Other times, the changes result in the common dog wart, or sebaceous adenoma.
Sebaceous adenomas are benign tumors of the oil gland (sebaceous) cells of the skin. The result is a cauliflower-like eruption that is unsightly, but not dangerous.
In some cases, dogs may develop sebaceous cysts or even seborrhea (dermatitis).
How to Identify Sebaceous Adenomas in Dogs
The term “sebaceous” refers to specific glands found under the skin of all mammals.
They are found all over the body in people with the exception of the palm of the hands and soles of the feet.
In dogs, sebaceous glands cover the entire body with the exception of the paw pads.
Some tell-tale signs of a sebaceous adenoma include:
- Sebaceous adenomas feel oily when gently squeezed.
- Look like a stalk of cauliflower.
- Sometimes secrete liquid that dries up and crusts.
These glands are located just beneath the surface of the skin and produce an oily substance known as sebum. Sebaceous glands are attached to hair (fur) follicles.
The glands release sebum which then travels up the follicle via the fur and is then transferred over the skin.
Any disruption of the normal pH balance of a dog’s skin (about 7.5 on the standard pH balance scale of 0 – 14) can cause too much sebum (oily skin) or not enough sebum (dry skin).
These benign growths are common in dogs, especially middle-aged and older dogs.
Sebaceous adenomas in dogs are simply benign (not cancerous) tumors.
Can Sebaceous Adenomas in Dogs Become Cancerous?
Sebaceous adenomas are rarely cancerous.
Occasionally, what seems like a simple “old dog wart” or sebaceous adenoma, is actually something entirely different.
The problem with lumps and bumps in dogs is that they’re impossible to accurately diagnosis without a biopsy or fine-needle aspiration.
Only about 2% of sebaceous tumors are malignant (cancerous).
The good news is that even if the tumor is malignant, they rarely spread.
Malignant, localized tumors are easier to treat (depending on their location) through surgical removal.
If surgical removal is necessary, a wide-margin around the tumor is excised in order to capture all of the cancerous cells.
Malignant Tumors You Should Know About
Any time you hear the word “carcinoma”, think cancer.
However, this specific type of tumor is rarely malignant and is unlikely to spread. For that reason, treatment options are easier and quicker.
In the unlikely event that your dog has sebaceous carcinoma, the veterinarian will discuss the treatment options with you.
Don’t be afraid to ask about the prognosis, staging, or grading of the tumor.
Malignant tumors require a surgical procedure in order to get wide margins and deeper tissue planes. For this reason, the procedure is done under general anesthesia.
If further treatment is needed, your veterinarian will inform you of options.
Mast Cell Tumors
The first malignant tumor that comes to mind are mast cell tumors.
Generally speaking, they don’t have the same cauliflower appearance of a sebaceous adenoma, but they still require the care of a licensed veterinarian.
Mast cell tumors can appear anywhere on the body and are not easily identified without a biopsy. Depending on the stage and grade of the tumor, surgical removal may be recommended.
During the operation, a wide margin of skin around the tumor is taken for further testing.
The idea is to get all of the cancer out and to make sure it hasn’t had a chance to spread.
Melanoma is a type of skin cancer that can affect people and pets. The disease is caused by exposure to direct sunlight and results in a dark sore or lump on the dog’s body.
Like many new lumps and bumps, it’s hard to know exactly what you’re dealing with until you seek the help of a veterinarian.
If you spot a lump on your dog’s head (including the mouth, lips, and eye) that doesn’t share any of the characteristics of a sebaceous adenoma, make an appointment with the veterinarian as soon as possible.
The life expectancy of a dog with malignant melanoma depends on the stage and grade of the lump.
Other factors that could play into your dog’s life expectancy include age and underlying health conditions.
What’s the Difference Between Sebaceous Adenomas and Sebaceous Hyperplasia?
Benign tumors in dogs can all look very much alike. Common tumors of the sebaceous glands include (but are not limited to):
- Nodular hyperplasia
- Sebaceous Epithelioma
- Meibomian Adenoma
- Meibomian Ductal Adenoma
- Hepatoid Gland Adenoma
- Hepatoid Gland Epithelioma
The differences involve complicated processes within the skin cells and the various names generally refer to where on the dog’s body the tumors occur (for example, meibomian adenomas occur around the eyelid and hepatoid gland adenoma refers to enlarged sweat glands located around the dog’s anus).
Which Dog Breeds are More Likely to Develop Sebaceous Adenomas?
Dogs between 8-13 years are at an increased risk and the breeds that are genetically predisposed include:
- English Cocker Spaniel
- Cocker Spaniel
- Siberian Husky,
- Alaskan Malamute
- West Highland White Terrier
- Cairn Terrier
- Miniature Poodle
- Miniature Schauzer
- Toy Poodle
- Shih Tzu
- Basset Hounds
- Kerry Blue Terriers.
3 Easy Treatments for Sebaceous Adenomas in Dogs.
It’s important to emphasize just how many different types of benign tumors dogs can develop.
To an untrained eye, they can look a lot alike. Ultimately, the important thing isn’t so much the official title of the tumor. What’s important is making sure the tumor is non-cancerous.
Do not attempt to remove tumors or cysts from home. In addition to causing your dog extreme pain, there is a high risk of infection which can lead to more problems in the long run.
1. Do Nothing
Veterinarians see these common benign tumors frequently. Generally, the advice is to do nothing at all. Sebaceous adenomas are common in middle-aged and senior dogs.
They will not go away on their own, but they shouldn’t pose a problem either. Unless the tumor is in a place where it is particularly bothersome to the dog, it’s safer to leave it alone than to subject an older dog to anesthesia.
2. Watch For Changes
This isn’t exactly a “treatment”, but it’s still an important thing to watch for. It’s rare for sebaceous tumors to become cancerous, but it’s worth watching for signs of change including the following:
- sudden growth of the tumor
- changes in color and texture
- signs of ulceration or bleeding
- excessive scratching or biting of the area
The signs noted above do not mean that the sebaceous tumor has become cancerous.
Sebaceous adenomas can be itchy for dogs and, depending on their location, your dog may decide to bite on it or scratch the area excessively.
Redness, inflammation, and bleeding could be a sign that the lump should be removed.
They can also be a sign of developing cancer in older dogs.
Remember that multiple problems can be going on in your dog at once. That doesn’t mean they are all dangerous.
It’s very important to bring your middle-aged or senior dog for annual check-ups to establish a baseline of what’s “normal” for your dog.
3. Focus on Your Dog’s General Health
It’s easy to become hyper-focused on the benign tumor and forget about the health of the dog as a whole.
Changes to eating habits, appetite, lethargy, vomiting and/or diarrhea can be symptoms of anything from parasitic infections to an upset stomach.
If your dog does exhibit other signs of illness as noted above, be sure to have a veterinarian do an assessment. Better safe than sorry.
Frequently Asked Questions About Sebaceous Adenomas in Dogs
How Do You Treat Sebaceous Adenomas?
In most cases, aggressive treatment is not necessary. They are considered a cosmetic legion. They may be unsightly, but are not usually dangerous.
Could a sebaceous adenoma fall off?
Unfortunately, sebaceous adenomas do not fall off on their own.
How can I tell if my dog has a sebaceous adenoma?
These benign tumors of the oil glands are also known as “old dog warts” because of their appearance.
They commonly affect middle age to senior dogs (especially terriers, poodles, cocker spaniels and miniature schnauzers).
Look for multiple raised, hairless, lobulated (having small lobes) masses that look white or pale pink. They are typically 1/4 inch to 1 inch in diameter and appear on the trunk, legs, feet, or face.
Can sebaceous adenomas become cancerous?
Sebaceous adenomas do not become cancerous. However, it’s always best for a veterinarian to make the diagnosis. Sometimes lumps end up looking alike and it’s difficult to tell a benign lump from a cancerous one.
At the end of the day, it’s important to remember that cysts and tumors can look very much alike. Watch for changes in size and the overall health of your dog.
Lumps and bumps in dogs are complicated and can only truly be diagnosed through examination of the cells.
This post was meant for educational purposes only and has not been verified by a licensed veterinarian. Please bring your dog to a professional for diagnosis, treatment, and follow-up.
Dermatology Clinic for Animals