Scent gland
Scent glands are exocrine glands found in most mammals. They produce semi-viscous secretions which contain pheromones and other semiochemical compounds. These odor-messengers indicate information such as status, territorial marking, mood, and sexual power. The odor may be subliminal—not consciously detectable. Though it is not their primary function, the salivary glands may also function as scent glands in some animals.
In even-toed ungulates
The even-toed ungulates (Artiodactyla) have many specialized skin glands, the secretions of which are involved in semiochemical communication. These glands include the sudoriferous glands (located on the forehead, between the antlers and eyes), the preorbital glands (extending from the medial canthus of each eye), the nasal glands (located inside the nostrils), the interdigital glands (located between the toes), the preputial gland (located inside the foreskin of the penis), the metatarsal glands (located outside of the hind legs), and the tarsal glands (located inside of the hind legs).