Sebaceous Cysts in Dogs

The appearance of a sebaceous cyst can vary depending on the type.

• There may be a raised area of skin called a nodule
• Cysts may be round or elongated
• Some cysts are slightly mobile under the skin
• Size can vary from less than ½ an inch to over 2 inches
• You may see multiple tumors
• There could be inflammation
• A cyst can become infected
• A cyst may bleed
• The cyst may ooze a yellow substance

Types

Sebaceous cysts are prone to secondary infection. It is recommended that you have a veterinarian check any type of growth that may appear on your dog.

• Sebaceous gland overgrowth or hyperplasia
• These usually appear on older dogs
• They present as a shiny lump
• This type of cyst is most often seen on the head and abdomen
• Manchester, Wheaton, and Welsh Terriers are prone
• Sebaceous gland adenoma/epithelioma
• These are usually found on older canines
• The cysts are found on the head and may have pus, covered with crust
• They can sometimes be found on the eyelid
• Alaskan Malamute, Samoyed, Husky, Coonhound and English Cocker Spaniel are the breeds that are predisposed
• Sebaceous gland hamartoma
• This type of cyst is often noticed after birth
• They are usually about 2 inches in length or diameter
• Sebaceous gland adenocarcinoma
• These are malignant cysts found in middle age to older dogs
• Males are predisposed
• Cavalier King Charles Spaniels, Cocker Spaniels, Scottish, Cairn and West Highland White Terriers are the most likely breed to have this cyst though it is rare
• This cyst can metastasize to the lymph nodes and lungs

Not only can cysts be unsightly, but they can also emit a foul odor or pus. Secondary infection or the possibility of a malignancy are good reasons to have a cyst investigated by the veterinarian.

• Genetic predisposition
• Injury or trauma
• Blockage of a follicle opening (similar to a blocked pore in humans)
• Insect bite reaction
• Allergic reaction
• Follicular inactivity
• Lack of sebum secretion (for example sebaceous adenitis)
• Swollen hair follicle
• Hormonal imbalance

The veterinarian will carefully check the entire body of your furry family member to determine the location, number, and appearance of the cysts.

Studies have determined that the best method of evaluating the tissues that make up the cyst is histopathology. This involves a microscopic examination of the tissue (removed by needle aspirate for biopsy, or completely extracted surgically) in order to determine the nature of the cyst. Determining the cause, discovering the prognosis, and ruling out other skin conditions are quite possible with histopathology.

Treatment will depend upon the state of the cysts, the number of cysts, and the health condition of your beloved pet.

If the cyst appears to be relatively new in appearance, you and the veterinary caregiver may take a wait and see approach, which basically means delaying any further treatment until the cyst, if it does, develops.

At a later time, the veterinarian may choose to open and drain the cyst and treat it with a topical medication.

If the cyst has ruptured by the time you make the visit to the clinic, the veterinarian may decide to treat any inflammation or infection that is present, and then surgically remove the cyst. Sometimes a cyst might need to be treated for infection first, and then when that is cleared up, draining is done, and finally a surgical procedure for removal.

If a cyst is found to be a malignant adenocarcinoma, chemotherapy and radiation will most likely follow the best option, which is surgery.

It should be noted that with sebaceous gland overgrowth or adenoma, recurrence is common. The prognosis of removal is usually good, but the recurrence factor must be kept in mind. Also, if many cysts are present, removal is not an easy task.

If the cysts found on your dog are cancerous, then the recovery and management will involve subsequent treatment with follow up appointments to determine if the cancer is being eradicated.

In the case of the simple removal of a few cysts, you will be required to keep the area clean. However, you will be advised not to bathe your dog until the veterinary caregiver gives permission.

Your canine companion may have to wear an Elizabethan collar to prevent him from licking or biting the area as it heals. Check the surgery site daily for swelling, redness or bleeding. Consult with the veterinary team if you are unsure of the condition of the surgery site, or if you feel the wound is not improving. The veterinarian will prescribe additional topical medication or antibiotics if necessary.

Though the area where the cysts were located will eventually heal, it is not uncommon for them to resurface, or for new cysts to appear.