Apocrine Gland Cysts and Adenomas in Dogs

Apocrine gland cysts and adenomas are common benign conditions seen in middle-aged to older dogs, particularly affecting breeds like the Great Pyrenees, Chow Chows, and Alaskan Malamutes. These cysts and adenomas develop from apocrine glands, which are associated with hair follicles and are found in the skin. This article provides an in-depth look at these conditions, including causes, symptoms, and treatment options.

What are Apocrine Gland Cysts?

Apocrine gland cysts are non-cancerous cysts that occur in the skin of dogs. They are typically seen in the middle to upper skin layers, loosely associated with hair follicles. Apocrine cysts can form on the head, neck, and other areas, often presenting as one or more fluid-filled sacs under the skin. These cysts are usually benign, meaning they do not spread or become cancerous.

There are two forms of apocrine gland cysts:

Localized Apocrine Cysts: These develop in or near individual hair follicles and are more commonly found on the head and neck of dogs.
Diffuse Apocrine Cysts: This form involves multiple cysts forming in the apocrine glands associated with multiple hair follicles. They can appear in areas of uninjured skin, making them harder to treat if they become widespread.

While benign, these cysts may sometimes cause discomfort, especially if they grow large or rupture.

What are Apocrine Gland Adenomas?

Apocrine gland adenomas are benign tumors that can arise in the apocrine glands. They appear as firm to soft masses and may contain fluid that ranges in color from clear to brownish. Typically, these cysts are not larger than 1.6 inches (4 centimeters) in diameter. Like apocrine cysts, adenomas are also found on the head, neck, and legs of older dogs, and, in rare cases, cats and horses.

Apocrine adenomas come in two types:

Apocrine Adenomas: These are solid, benign growths formed by the apocrine glands.
Apocrine Ductular Adenomas: These involve the ducts of the apocrine glands, leading to cystic formations.

Breeds at Higher Risk

Certain dog breeds are more prone to developing apocrine gland cysts and adenomas. The most commonly affected breeds include:

Great Pyrenees
Chow Chows
Alaskan Malamutes

Older dogs in these breeds are more likely to develop these conditions, though the exact cause remains unknown. Genetics, environmental factors, and age may play a role in their development.

Symptoms to Look For

Visible cysts or lumps on the head, neck, or legs
Fluid-filled sacs under the skin
Soft to firm masses that may vary in size
Discoloration of the skin or cyst fluid (clear to brown)
Possible rupture of cysts causing localized inflammation or infection

While these cysts and adenomas are generally painless, they can cause discomfort if they rupture or grow in sensitive areas.

Treatment Options

The primary treatment for apocrine gland cysts and adenomas is surgical removal. However, this can be challenging, particularly in cases where cysts are diffuse and spread across a larger area of the skin. In localized cases, the surgery is typically straightforward, and the prognosis is excellent after removal.

In situations where surgery is not an option, veterinarians may recommend monitoring the cysts for changes in size or discomfort. If cysts rupture, antibiotics may be required to prevent infection.

Apocrine gland cysts and adenomas in dogs are generally benign and treatable conditions. While they can cause cosmetic issues and occasional discomfort, early detection and treatment can help prevent complications. Owners of at-risk breeds such as Great Pyrenees, Chow Chows, and Alaskan Malamutes should monitor their dogs for the development of these cysts as they age, and consult a veterinarian for proper diagnosis and treatment.