Dogs have glands throughout their body, but the ones most pet owners are asking about are the anal glands (anal sacs), located on either side of the anus. Beyond those, dogs also have salivary glands, lymph nodes you can feel through the skin, mammary glands, thyroid glands, and several others worth knowing about.
Anal Glands
The anal glands are by far the most searched-for glands in dogs, usually because something has gone wrong with them. These two small sacs sit just inside the anal opening. If you picture the anus as a clock face, one gland sits at roughly the 4 o’clock position and the other at 8 o’clock. Each one feels like a small, firm, marble-sized lump just beneath the muscular ring of the anal sphincter.
These sacs produce a strong-smelling, oily fluid that normally gets expressed in small amounts each time your dog has a bowel movement. The scent is part of how dogs identify each other. Problems arise when the sacs don’t empty properly and become impacted, infected, or abscessed. Signs include scooting on the floor, licking at the rear end, a fishy smell, or visible swelling near the anus. Some dogs, especially smaller breeds, need their anal glands manually expressed by a groomer or veterinarian on a regular basis.
Salivary Glands
Dogs have four major pairs of salivary glands, each named for the part of the head or jaw where it sits:
- Parotid gland: A triangular gland sitting just over the vertical ear canal, near the base of the ear.
- Mandibular gland: A large gland you can sometimes feel just behind and below the angle of the jawbone. It’s the most prominent of the four.
- Sublingual gland: Closely paired with the mandibular gland and partially sharing the same capsule, located under the tongue.
- Zygomatic gland: Tucked just below and slightly in front of the eye, on the inner side of the cheekbone. When this gland swells or becomes infected, it can push the eye outward or cause swelling below the eye socket.
Salivary gland problems aren’t common, but a mucocele (a buildup of saliva that leaks from a damaged gland or duct) is the condition owners are most likely to encounter. It typically appears as a soft, painless swelling under the jaw or tongue.
Lymph Nodes
Lymph nodes are often called “glands,” and there are three pairs you can feel on a healthy dog. Knowing where they are matters because swollen lymph nodes can be an early sign of infection, inflammation, or lymphoma.
- Mandibular (submandibular): Under the jaw, in the soft tissue beneath the lower edge of the jawbone. Their exact position varies a bit from dog to dog.
- Superficial cervical (prescapular): In front of the shoulder joint, in the loose skin of the lower neck. You can find them by feeling just ahead of where the shoulder blade begins.
- Popliteal: On the back of each hind leg, opposite the knee (stifle) joint. These are the easiest to locate on most dogs because the area has less surrounding tissue.
In a healthy dog, these nodes are small, smooth, and roughly the same size on both sides. If one feels noticeably larger than its partner on the opposite side, or if multiple nodes are enlarged, that’s worth having checked.
Mammary Glands
Female dogs have five pairs of mammary glands, ten in total, arranged in two symmetrical rows running from the chest all the way down to the groin. They start near the front legs and end near the hind legs. Male dogs have the same nipple arrangement, though the glandular tissue behind them is rudimentary.
Mammary tumors are common in unspayed female dogs, particularly those spayed later in life. You can check for lumps by gently running your fingers along each row of mammary tissue. Any firm lump, even a small one, is worth a veterinary exam. About half of mammary tumors in dogs are benign, but the other half are malignant, so early detection matters.
Thyroid Gland
The thyroid gland controls your dog’s metabolism and sits in the neck. It has two lobes positioned on either side of the trachea (windpipe), slightly toward the back and side. In most dogs, the thickest part of each lobe sits near the second or third cervical vertebra, which is the upper portion of the neck just below the base of the skull. You can’t feel a normal thyroid gland through the skin. If you can feel a lump in that area, it could indicate an enlarged or abnormal thyroid.
Hypothyroidism, where the thyroid produces too little hormone, is one of the most common hormonal disorders in dogs. It causes weight gain, lethargy, hair thinning, and skin problems. It’s diagnosed with a blood test rather than by feeling for the gland itself.
Adrenal Glands
Dogs have two adrenal glands, one near each kidney, deep inside the abdomen. These small glands produce stress hormones, help regulate blood pressure, and play a role in metabolism. They’re tucked against major blood vessels near the aorta and are impossible to feel from the outside. Veterinarians locate them using ultrasound.
The most common adrenal gland problem in dogs is Cushing’s disease, where one or both glands overproduce stress hormones. This causes increased thirst, frequent urination, a pot-bellied appearance, and hair loss. Addison’s disease is the opposite condition, where the glands don’t produce enough hormones.
Prostate Gland
In male dogs, the prostate gland wraps around the urethra near the base of the bladder. Its exact position shifts with age. In puppies under two months, it sits in the lower abdomen. As the dog matures, it moves back into the pelvic canal. After sexual maturity, it grows and pushes forward into the abdominal cavity again. The prostate makes direct contact with the rectum above it, which is why veterinarians can assess its size through a rectal exam.
Unneutered male dogs commonly develop an enlarged prostate as they age, which can cause difficulty urinating or defecating. Neutering typically causes the prostate to shrink significantly within weeks.
Tail Gland
Dogs have a specialized oil-producing gland on the top side of the tail, a few centimeters from the base. This gland, sometimes called the supracaudal or violet gland, produces sebaceous oils. In most dogs you’d never notice it, but when it becomes overactive, a condition called “stud tail,” the fur over the gland gets greasy, the hair follicles become plugged, and the skin turns scaly or develops a bald patch. It’s most common in intact males but can affect any dog.