Cysts in dogs may appear as a raised lump or growth under the skin, or they may not be visible to the naked eye. Cysts are generally indistinguishable from other tumors without a biopsy and microscopic examination of the tissue, reports VCA Animal Hospitals.
Sebaceous cysts are some of the most common superficial cysts, reports PetMD. These growths occur when a sebaceous gland, which normally secretes necessary oils onto the skin and hair, gets clogged. It may be clogged by dirt, shed skin cells, sweat or outside substances. These are usually benign and may eventually rupture on their own, although some can develop chronic issues that need veterinary treatment. There is a malignant form of sebaceous cyst, known as sebaceous adenoma, which is usually easily treated with surgical removal.
Other cysts form when sweat glands, pores or hair follicles are clogged, according to VCA Animal Hospitals. Trauma can also form a type of cyst, known as a false cyst, if it is severe enough to kill tissue. The area then fills with fluid, forming a cyst. This type of cyst usually resolves by itself.
Owners who notice a strange growth or lump on their dogs should visit a veterinarian to get an accurate diagnosis, reports PetMD. Most cysts are benign and are fairly easily treated with surgical removal, but growths can also be cancerous.